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Note: This page contains sample records for the topic "radiant heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

Radiant Heating  

Energy.gov (U.S. Department of Energy (DOE))

Radiant heating systems involve supplying heat directly to the floor or to panels in the walls or ceiling of a house. The systems depend largely on radiant heat transfer: the delivery of heat...

2

Radiant heat transfer from storage casks to the environment  

SciTech Connect

A spent fuel storage cask must efficiently transfer the heat released by the fuel assemblies through the cask walls to the environment. This heat must be transferred through passive means, limiting the energy transfer mechanisms from the cask to natural convection and radiation heat transfer.. Natural convection is essentially independent of the characteristics of the array of casks, provided there is space between casks to permit a convection loop. Radiation heat transfer, however, depends on the geometric arrangement of the array of casks because the peripheral casks will shadow the interior casks and restrict radiant heat transfer from all casks to the environment. The shadowing of one cask by its neighbors is determined by a view factor that represents the fraction of radiant energy that leaves the surface of a cask and reaches the environment. This paper addresses the evaluation of the view factor between a centrally located spent fuel storage cask and the environment. By combining analytic expressions for the view factor of (1) infinitely long cylinders and (2) finite cylinders with a length-to-diameter ratio of 2 to represent spent fuel storage casks, the view factor can be evaluated for any practical array of spent fuel storage casks.

Carlson, R W; Hovingh, J; Thomas, G R

1999-05-10T23:59:59.000Z

3

Radiant Heating | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Radiant Heating Radiant Heating Radiant Heating June 24, 2012 - 5:52pm Addthis In-wall radiant heating in a house under construction near Denver. | Photo courtesy of Warren Gretz, NREL. In-wall radiant heating in a house under construction near Denver. | Photo courtesy of Warren Gretz, NREL. Radiant heating systems supply heat directly to the floor or to panels in the wall or ceiling of a house. The systems depend largely on radiant heat transfer -- the delivery of heat directly from the hot surface to the people and objects in the room via infrared radiation. Radiant heating is the effect you feel when you can feel the warmth of a hot stovetop element from across the room. When radiant heating is located in the floor, it is often called radiant floor heating or simply floor heating.

4

Radiant Heating | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Radiant Heating Radiant Heating Radiant Heating June 24, 2012 - 5:52pm Addthis In-wall radiant heating in a house under construction near Denver. | Photo courtesy of Warren Gretz, NREL. In-wall radiant heating in a house under construction near Denver. | Photo courtesy of Warren Gretz, NREL. Radiant heating systems supply heat directly to the floor or to panels in the wall or ceiling of a house. The systems depend largely on radiant heat transfer -- the delivery of heat directly from the hot surface to the people and objects in the room via infrared radiation. Radiant heating is the effect you feel when you can feel the warmth of a hot stovetop element from across the room. When radiant heating is located in the floor, it is often called radiant floor heating or simply floor heating.

5

Numerical heat transfer attic model using a radiant barrier system  

Science Conference Proceedings (OSTI)

A two-dimensional, steady-state finite-element model was developed to simulate the thermal effects of the application of an attic radiant barrier system (ARBS) inside a ventilated residential attic. The attic is ventilated using the exhaust air from an evaporative cooler. The study uses a {kappa}-{epsilon} turbulent model to describe the velocity and temperature distributions in the attic. The ambient temperature and solar isolation densities on the outside inclined attic surfaces are used as driving functions for the model. The model also included the appropriate heat exchange modes of convection and radiation on these outside surfaces. Several recirculation zones were visually observed in the attic flow pattern. Also, the use of the ARBS seems to lower the heat transfer through the ceiling by 25--30%, but this effect decreases significantly as the outside ventilation rates are increased through the attic space. The 2D model revealed some interesting temperature distributions along the attic surfaces that could not have been predicted by the one-dimensional models. The lower emissivity ARBS seems to raise the temperature of the inclined attic surfaces as well as the temperature of the exhausted ventilation air.

Moujaes, S.F.; Alsaiegh, N.T.

2000-04-01T23:59:59.000Z

6

Radiant Heating Basics | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Radiant Heating Basics Radiant Heating Basics Radiant Heating Basics August 19, 2013 - 10:33am Addthis Radiant heating systems involve supplying heat directly to the floor or to panels in the walls or ceiling of a house. The systems depend largely on radiant heat transfer: the delivery of heat directly from the hot surface to the people and objects in the room via the radiation of heat, which is also called infrared radiation. Radiant heating is the effect you feel when you can feel the warmth of a hot stovetop element from across the room. When radiant heating is located in the floor, it is often called radiant floor heating or simply floor heating. Despite the name, radiant floor heating systems also depend heavily on convection, the natural circulation of heat within a room, caused by heat rising from the floor. Radiant floor

7

Radiant Heating Basics | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Radiant Heating Basics Radiant Heating Basics Radiant Heating Basics August 19, 2013 - 10:33am Addthis Radiant heating systems involve supplying heat directly to the floor or to panels in the walls or ceiling of a house. The systems depend largely on radiant heat transfer: the delivery of heat directly from the hot surface to the people and objects in the room via the radiation of heat, which is also called infrared radiation. Radiant heating is the effect you feel when you can feel the warmth of a hot stovetop element from across the room. When radiant heating is located in the floor, it is often called radiant floor heating or simply floor heating. Despite the name, radiant floor heating systems also depend heavily on convection, the natural circulation of heat within a room, caused by heat rising from the floor. Radiant floor

8

Energy Basics: Radiant Heating  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

very low heat capacity and have the quickest response time of any heating technology. More Information Visit the Energy Saver website for more information about radiant heating...

9

Energy Basics: Radiant Heating  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

low heat capacity and have the quickest response time of any heating technology. More Information Visit the Energy Saver website for more information about radiant heating in homes...

10

Finite-volume model for chemical vapor infiltration incorporating radiant heat transfer. Interim report  

SciTech Connect

Most finite-volume thermal models account for the diffusion and convection of heat and may include volume heating. However, for certain simulation geometries, a large percentage of heat flux is due to thermal radiation. In this paper a finite-volume computational procedure for the simulation of heat transfer by conduction, convection and radiation in three dimensional complex enclosures is developed. The radiant heat transfer is included as a source term in each volume element which is derived by Monte Carlo ray tracing from all possible radiating and absorbing faces. The importance of radiative heat transfer is illustrated in the modeling of chemical vapor infiltration (CVI) of tubes. The temperature profile through the tube preform matches experimental measurements only when radiation is included. An alternative, empirical approach using an {open_quotes}effective{close_quotes} thermal conductivity for the gas space can match the initial temperature profile but does not match temperature changes that occur during preform densification.

Smith, A.W.; Starr, T.L. [Georgia Institute of Technology, Atlanta, GA (United States). School of Materials Science and Engineering

1995-05-01T23:59:59.000Z

11

Radiant Heating | Department of Energy  

NLE Websites -- All DOE Office Websites (Extended Search)

heating because it eliminates duct losses. People with allergies often prefer radiant heat because it doesn't distribute allergens like forced air systems can. Hydronic...

12

An Evaluation of the Placement of the Placement of Radiant Barriers on their Effectiveness in Reducing Heat Transfer in Attics  

E-Print Network (OSTI)

Experimental tests were conducted to measure the influence of radiant barriers and the effect of the radiant barrier location on attic heat transfer. All the tests were conducted in an attic simulator at a steady state. The heat flux through the attic floor was measured at two different roof deck temperatures (120°F and 140°F). The temperature distribution within the base fibrous insulation was also measured. Three different solid kraft laminates with aluminum foil backing were tested. There was a 34 percent reduction (sample A) in heat flux through the ceiling for the case where the radiant barrier was placed 6 inches below the roof deck in addition to the base fibrous insulation (R-11), with the roof deck at 140 F. The reduction for the same sample with the radiant barrier placed on the studs of the attic floor was 46 percent. For all the three samples, the heat flux through the attic floor was reduced when the radiant barrier was placed on the attic floor studs.

Katipamula, S.; O'Neal, D.

1986-01-01T23:59:59.000Z

13

A transient heat and mass transfer model of residential attics used to simulate radiant barrier retrofits. Part 1: Development  

SciTech Connect

This paper describes a transient heat and mass transfer model of residential attics. The model is used to predict hourly ceiling heat gain/loss in residences with the purpose of estimating reductions in cooling and heating loads produced by radiant barriers. The model accounts for transient conduction, convection, and radiation and incorporates moisture and air transport across the attic. Environmental variables, such as solar loads on outer attic surfaces and sky temperatures, are also estimated. The model is driven by hourly weather data which include: outdoor dry bulb air temperature, horizontal solar and sky radiation, wind speed and direction, relative humidity (or dew point), and cloud cover data. The output of the model includes ceiling heat fluxes, inner and outer heat fluxes from all surfaces, inner and outer surface temperatures, and attic dry bulb air temperatures. The calculated fluxes have been compared to experimental data of side-by-side testing of attics retrofit with radiant barriers. The model predicts ceiling heat flows with an error of less than 10% for most cases.

Medina, M.A. [Texas A and M Univ., Kingsville, TX (United States). Dept. of Mechanical and Industrial Engineering; O`Neal, D.L. [Texas A and M Univ., College Station, TX (United States). Dept. of Mechanical Engineering; Turner, W.D. [Texas Engineering Experiment Station, College Station, TX (United States). Energy Systems Lab.

1998-02-01T23:59:59.000Z

14

Development of a Transient Heat and Mass Transfer Model of Residential Attics to Predict Energy Savings Produced by the Use of Radiant Barriers  

E-Print Network (OSTI)

A transient heat and mass transfer model was developed to predict ceiling heat gain/loss through the attic space in residences and to accurately estimate savings in cooling and heating loads produced by the use of radiant barriers. The model accounted for transient conduction, convection and radiation and incorporated moisture and air transport across the attic. Environmental variables such as solar loads on outer attic surfaces and sky temperatures were also estimated. The model was driven by hourly weather data which included: time, outdoor air temperature, horizontal sun and sky radiation, wind speed and direction, relative humidity (dew point), and cloud cover data. The outputs of the model were ceiling heat fluxes, inner and outer heat fluxes from all surfaces, inner and outer surface temperatures and attic air temperatures. Transient conduction was modeled using response factors. Response factors were calculated for each attic component based on construction type. Convective heat transfer was modeled using “flat plate” correlations found in the literature and radiative heat transfer was modeled using radiation enclosure theory. Moisture was incorporated via a condensation/evaporation model. A new procedure was developed to account for attic air stratification. Both forced and natural attic ventilation patterns were added to the model for three types of louver combination arrangements. An iterative technique was used to solve a set of simultaneous heat balance equations. The model predictions were compared to experimental data gathered throughout a three year experimental effort of side-by-side testing of attics retrofit with radiant barriers. The model was compared to the experimental data for a variety of situations which included: different attic insulation levels, various attic airflow rates, cooling and heating seasons, and different radiant barrier orientations. The model predicted ceiling heat flows within 10% for most cases. The model was used to run simulations and parametric studies under a diversity of climates, insulation levels and attic airflow patterns. Model predictions and results were presented on the basis of savings produced by the use of radiant barriers. Hourly, daily, and seasonal predictions by the model were in excellent agreement with observed experimental data and with literature.

Medina, M. A.

1992-12-01T23:59:59.000Z

15

Radiant Barrier Performance during the Heating Season  

E-Print Network (OSTI)

Results of winter experiments conducted in Central Texas are presented. The experiments were side-by-side tests using two identical 144 ft2 houses which responded similarly to weather variations prior to any retrofits. Two radiant barrier orientations were tested, horizontal barrier and barrier against the rafters, in vented and non-vented attics. The results compiled in this paper are for attics with R-19 fiberglass insulation. The data showed that radiant barriers were still effective during the winter season. During a typical day radiant barriers prevented approximately 9-17 percent of the indoor heat from escaping into the attic. No significant difference in moisture accumulation was detected in the attic with the radiant barrier.

Medina, M. A.; O'Neal, D. L.; Turner, W. D.

1992-05-01T23:59:59.000Z

16

A transient heat and mass transfer model of residential attics used to simulate radiant barrier retrofits. Part 2: Validation and simulations  

Science Conference Proceedings (OSTI)

A computer program was developed and used to implement the model described on Part 1 of this paper. The program used an iterative process to predict temperatures and heat fluxes using linear algebra principles. The results from the program were compared to experimental data collected during a three-year period. The model simulated different conditions such as variations in attic ventilation, variations in attic ceiling insulation, and different radiant barrier orientations for summer and winter seasons. It was observed that the model predicted with an error of less than 10% for most cases. This paper presents model results for nonradiant barrier cases as well as cases for radiant barriers installed horizontally on top of the attic floor (HRB) and for radiant barriers stapled to the attic rafters (TRB). Savings produced by radiant barriers and sensitivity analyses are also presented. The model results supported the experimental trend that emissivity was the single most significant parameter that affected the performance of radiant barriers.

Medina, M.A. [Texas A and M Univ., Kingsville, TX (United States). Dept. of Mechanical and Industrial Engineering

1998-02-01T23:59:59.000Z

17

Radiant zone heated particulate filter  

DOE Patents (OSTI)

A system includes a particulate matter (PM) filter including an upstream end for receiving exhaust gas and a downstream end. A radiant zoned heater includes N zones, where N is an integer greater than one, wherein each of the N zones includes M sub-zones, where M is an integer greater than or equal to one. A control module selectively activates at least a selected one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones, restricts exhaust gas flow in a portion of the PM filter that corresponds to the selected one of the N zones, and deactivates non-selected ones of the N zones.

Gonze, Eugene V [Pinckney, MI

2011-12-27T23:59:59.000Z

18

Impact of Solar Heat Gain on Radiant Floor Cooling System Design  

E-Print Network (OSTI)

Bauman F. 2013. Impact of Solar Heat Gain on Radiant FloorBauman F. 2013. Impact of Solar Heat Gain on Radiant FloorBauman F. 2013. Impact of Solar Heat Gain on Radiant Floor

Feng, Jingjuan Dove; Schiavon, Stefano; Bauman, Fred

2013-01-01T23:59:59.000Z

19

Experiment System Analysis of an Indirect Expansion Solar Assisted Water Source Heat Pump Radiant Floor Heating System  

Science Conference Proceedings (OSTI)

A solar assisted water source heat pump for Radiant Floor Heating (SWHP-RFH) experimental system with heat pipe vacuum tube solar collector as heating source and radiant floor as terminal device is proposed in the paper. The Mathematics Model of dynamic ... Keywords: solar energy, water source heat pump, radiant floor heating systems, system dynamic COP

Qu Shilin; Ma Fei; Liu Li; Yue Jie

2009-10-01T23:59:59.000Z

20

Inverse optimal design of the radiant heating in materials processing and manufacturing  

Science Conference Proceedings (OSTI)

Combined convective, conductive, and radiative heat transfer is analyzed during heating of a continuously moving load in the industrial radiant oven. A transient, quasi-three-dimensional model of heat transfer between a continuous load of parts moving inside an oven on a conveyor belt at a constant speed and an array of radiant heaters/burners placed inside the furnace enclosure is developed. The model accounts for radiative exchange between the heaters and the load, the conduction in the load, and convective heat transfer between the moving load and oven environment. The thermal model developed has been used to construct a general framework for an inverse optimal design of an industrial oven as an example. In particular, the procedure based on the Levenberg-Marquardt nonlinear least squares optimization algorithm has been developed to obtain the optimal temperatures of the heaters/burners that need to be specified to achieve a prescribed temperature distribution of the surface of a load. The results of calculations for several sample cases are reported to illustrate the capabilities of the procedure developed for the optimal inverse design of an industrial radiant oven.

Fedorov, A.G.; Lee, K.H.; Viskanta, R. [Purdue Univ., West Lafayette, IN (United States)] [Purdue Univ., West Lafayette, IN (United States)

1998-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "radiant heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Ocean Radiant Heating. Part I: Optical Influences  

Science Conference Proceedings (OSTI)

Radiative transfer calculations are used to quantify the effects of physical and biological processes on variations in the transmission of solar radiation through the upper ocean. Results indicate that net irradiance at 10 cm and 5 m can vary by ...

J. Carter Ohlmann; David A. Siegel; Curtis D. Mobley

2000-08-01T23:59:59.000Z

22

Where radiant barriers really shine  

Science Conference Proceedings (OSTI)

Manufactures of radiant barrier materials claim their products significantly cut cooling costs by reducing summertime radiant heat gain through attics and ceilings. A new study confirms that radiant barriers can indeed conserve cooling energy. However, the study`s authors found that radiant barriers are much more effective at reducing energy losses from attic air conditioner duct runs than at directly lowering heat transfer through the attic floor into conditioned living space. Furthermore the study demonstrated that radiant barrier savings can be significant even in a new well-weatherized house and that these saving may justify specifying smaller capacity cooling systems. This article discusses the findings of the study.

Engel, R.

1996-07-01T23:59:59.000Z

23

Design and Experiments of a Solar Low-temperature Hot Water Floor Radiant Heating System  

E-Print Network (OSTI)

The solar low-temperature hot water floor radiant heating system combines solar energy heating with floor radiant heating. This kind of environmental heating way not only saves fossil resources and reduces pollution, but also makes people feel more comfortable. First, the authors devised an experimental scheme and set up the laboratory. Second, we collected a great deal of data on the system in different situations. Finally, we conclude that such heating system is feasible and one of the best heating methods.

Wu, Z.; Li, D.

2006-01-01T23:59:59.000Z

24

Incorporating Radiant Heat Exchange into Finite Element Models of ...  

Science Conference Proceedings (OSTI)

In order to simplify this non-linear mode of heat transfer, the effects of ... Technical Risk Mitigation Through Rheometallurgical Generation of Process and ...

25

Heating energy measurements of unoccupied single-family houses with attics containing radiant barriers  

Science Conference Proceedings (OSTI)

Tests were conducted by Oak Ridge National Laboratory (ORNL) to determine the magnitude of the heating energy savings achieved by installing attic radiant barriers. The radiant barriers used for the test consist of a material with two reflective aluminum surfaces on a kraft paper base. The experiment was conducted in three unoccupied research houses operated by ORNL. Two variations in the installation of radiant barriers were studied. One house was used as the control house (no barrier was installed), while the other two were used to test the two methods for installing the radiant barriers. In one house, the radiant barrier was laid on top of the attic fiberglass batt insulation, and in the other house, the barrier was attached to the underside of the roof trusses. The attics of all three houses were insulated with a kraft-paper-faced R-19 fiberglass batt insulation. The winter test with the radiant barrier showed that the horizontal barrier was able to save space-heating electical energy in both the resistance and heat pump modes amounting to 10.1% and 8.5%, respectively. The roof truss radiant barrier increased consumption by 2.6% in the resistance mode and 4.0% in the heat pump mode. The horizontal orientation of the radiant barrier is the more energy-effective method of installation.

Levins, W.P.; Karnitz, M.A.

1987-01-01T23:59:59.000Z

26

Experimental Study on Operating Characteristic of the System of Ground Source Heat Pump Combined with Floor Radiant Heating of Capillary Tube  

Science Conference Proceedings (OSTI)

At first, the article presented particularly the working theory of the system of ground source heat pump combined with floor radiant heating of capillary tube, the characteristic of soil layers and the arrangement form of capillary tube mat and the floor ... Keywords: Ground source heat pump, Capillary tube, Radiant heating, Characteristic, Experiment

Yunzhun Fu; Cai Yingling; Jing Li; Yeyu Wang

2009-10-01T23:59:59.000Z

27

Heat transfer. [heat transfer roller employing a heat pipe  

SciTech Connect

A heat transfer roller embodying a heat pipe is disclosed. The heat pipe is mounted on a shaft, and the shaft is adapted for rotation on its axis.

Sarcia, D.S.

1978-05-23T23:59:59.000Z

28

Cooling energy measurements of houses with attics containing radiant barriers  

Science Conference Proceedings (OSTI)

Tests were conducted by Oak Ridge National Laboratory (ORNL) to determine the magnitude of the energy savings brought about by installing radiant barriers in the attics of single-family houses. The radiant barrier used for this test was a product with two reflective aluminum surfaces on a kraft paper base. The radiant barrier has the potential to reduce the radiant heat transfer component impinging on the fiberglass attic insulation. Working as a system in conjunction with an air space, the radiant barrier could theoretically block up to 95% of far-infrared radiation heat transfer. The results showed a savings in the cooling loads of 21% when the radiant barrier was laid on top of the attic fiberglass insulation and 13% with the radiant barrier attached to the underside of the roof trusses. The savings in electrical consumption was 17% and 9%, respectively.

Levins, W.P.; Karnitz, M.A.; Knight, D.K.

1986-01-01T23:59:59.000Z

29

Study of thermosiphon and radiant panel passive heating systems for metal buildings  

DOE Green Energy (OSTI)

A study of passive-heating systems appropriate for use on metal buildings is being conducted at Los Alamos National Laboratory for the Naval Civil Engineering Laboratory, Port Hueneme, California. The systems selected for study were chosen on the basis of their appropriateness for retrofit applications, although they are also suitable for new construction: simple radiant panels that communicate directly with the building interior and a backflow thermosiphon that provides heat indirectly.

Biehl, F.A.; Schnurr, N.M.; Wray, W.O.

1983-01-01T23:59:59.000Z

30

Combined Operation of Solar Energy Source Heat Pump, Low-vale Electricity and Floor Radiant System  

E-Print Network (OSTI)

Today energy sources are decreasing and saving energy conservation becomes more important. Therefore, it becomes an important investigative direction how to use reproducible energy sources in the HVAC field. The feasibility and necessity of using solar energy, low-vale electricity as heat sources in a floor radiant system are analyzed. This paper presents a new heat pump system and discusses its operational modes in winter.

Liu, G.; Guo, Z.; Hu, S.

2006-01-01T23:59:59.000Z

31

Study of the Heating Load of a Manufactured Space with a Gas-fired Radiant Heating System  

E-Print Network (OSTI)

A thermal balance mathematics model of a manufactured space with a gas-fired radiant heating system is established to calculate the heating load. Computer programs are used to solve the model. Envelope internal surface temperatures under different outdoor temperatures are obtained, and the heating load of the manufactured space is analyzed. The relationship between the envelope internal surface temperature and the workspace temperature is also analyzed in this paper. CFD simulation software is used to simulate the temperature field and the envelope's internal surface temperature of the manufacture space with hot-air heating system. Comparison and analysis of heating loads are done between the manufactured spaces with convection heating and radiant heating systems.

Zheng, X.; Dong, Z.

2006-01-01T23:59:59.000Z

32

Heat transfer system  

DOE Patents (OSTI)

A heat transfer system for a nuclear reactor is described. Heat transfer is accomplished within a sealed vapor chamber which is substantially evacuated prior to use. A heat transfer medium, which is liquid at the design operating temperatures, transfers heat from tubes interposed in the reactor primary loop to spaced tubes connected to a steam line for power generation purposes. Heat transfer is accomplished by a two-phase liquid-vapor-liquid process as used in heat pipes. Condensible gases are removed from the vapor chamber through a vertical extension in open communication with the chamber interior.

Not Available

1980-03-07T23:59:59.000Z

33

Heat transfer system  

DOE Patents (OSTI)

A heat transfer system for a nuclear reactor. Heat transfer is accomplished within a sealed vapor chamber which is substantially evacuated prior to use. A heat transfer medium, which is liquid at the design operating temperatures, transfers heat from tubes interposed in the reactor primary loop to spaced tubes connected to a steam line for power generation purposes. Heat transfer is accomplished by a two-phase liquid-vapor-liquid process as used in heat pipes. Condensible gases are removed from the vapor chamber through a vertical extension in open communication with the chamber interior.

McGuire, Joseph C. (Richland, WA)

1982-01-01T23:59:59.000Z

34

Numerical Simulation of Thermal Performance of Floor Radiant Heating System with Enclosed Phase Change Material  

E-Print Network (OSTI)

In the present paper, a kind of enclosed phase change material (PCM) used in solar and low-temperature hot water radiant floor heating is investigated. On the basis of obtaining the best performance of PCM properties, a new radiant heating structure of the energy storage floor is designed,which places heat pipes in the enclosed phase change material (PCM) layer, without concrete in it. The PCM thermal storage time is studied in relation to the floor surface temperature under different low-temperature hot water temperatures. With the method of enthalpy , the PCM thermal storage time is studied under different supply water temperatures, supply water flows, distances between water wipe in the floor construction, floor covers and insulation conditions.

Qiu, L.; Wu, X.

2006-01-01T23:59:59.000Z

35

Effect of Radiant Barrier Technology on Summer Attic Heat Load in South Texas  

E-Print Network (OSTI)

The objective of the study was to experimentally evaluate the performance of radiant barriers in single-family occupied housing units in South Texas. Ceiling heat fluxes, attic air temperatures, indoor air temperatures, ambient air temperatures. roof temperatures, and solar radiation were measured. Results of the radiant barrier experiment using two side-by-side 600 ft2 units are presented. Attic fiberglass insulation of nominal R-11 was installed in the two apartments when the units were last remodeled in 1974. The test houses responded similarly to weather variations, that is, attic temperature and heat flux profiles were similar in magnitude prior to the retrofit. Residents of the housing units were asked to set the thermostats at 76°F. Data were analyzed for periods of time which had the greatest attic temperatures (11 a.m. - 11 p.m.) and for which the indoor temperature differences were less than 1 percent. The results showed that radiant barriers reduced ceiling heat loads (on daily basis) by an average of 60 percent.

Ashley, R.; Garcia, O.; Medina, M. A.; Turner, W. D.

1994-01-01T23:59:59.000Z

36

Convection Heat Transfer  

Science Conference Proceedings (OSTI)

...Heat-Transfer Equations, Fundamentals of Modeling for Metals Processing, Vol 22A, ASM Handbook, ASM International, 2009, p 625â??658...

37

Heat transfer dynamics  

Science Conference Proceedings (OSTI)

As heat transfer technology increases in complexity, it becomes more difficult for those without thermal dynamics engineering training to choose between competitive heat transfer systems offered to meet their drying requirements. A step back to the basics of heat transfer can help professional managers and papermakers make informed decisions on alternative equipment and methods. The primary forms of heat and mass transfer are reviewed with emphasis on the basics, so a practical understanding of each is gained. Finally, the principles and benefits of generating infrared energy by combusting a gaseous hydrocarbon fuel are explained.

Smith, T.M. (Marsden, Inc., Pennsauken, NJ (United States))

1994-08-01T23:59:59.000Z

38

Radiant barrier applications: Symposium and workshop proceedings  

Science Conference Proceedings (OSTI)

Electric utilities and their customers are continually looking for ways to improve the thermal integrity of buildings. Radiant barrier systems can reduce summer air conditioning loads by reducing radiant heat transfer in attics. EPRI conducted two programs to help utilities with radiant barriers. A Symposium and Workshop were conducted in April 1988. The Symposium reviewed the state of the art in radiant barriers. The Workshop brought industry experts together to identify research needs for radiant barriers. The Workshop found that research is needed in six major areas. Listed in order of importance these are: (1) Field and laboratory testing, (2) Materials research, (3) Modeling, (4) Materials standards, (5) Economic issues, and (6) Installation methods. The leading research topics within these six major areas in order of importance include:(1) Modeling to fill voids in existing field data and aid in the development of performance standards, (2) Calculation of energy savings for various configurations, (3) Analysis of existing data to better understand radiant barrier performance, (4) Assessment of the effect of dust accumulation on performance, (5) Development of standard testing procedures, (6) Development of systems standards, (7) Measurement of changes in the emissivity of radiant barrier materials with time, (8) Determination of the possibility of moisture accumulation under horizontal radiant barriers during heating season operation, (9) Ventilation effects, (10) Configuration testing, (11) Costs of new and retrofit applications, and (12) Characterization of side effects. 34 refs., 5 figs.

Isaksen, L.

1989-02-01T23:59:59.000Z

39

Applied heat transfer  

Science Conference Proceedings (OSTI)

Heat transfer principles are discussed with emphasis on the practical aspects of the problems. Correlations for heat transfer and pressure drop from several worldwide sources for flow inside and outside of tubes, including finned tubes are presented, along with design and performance calculations of heat exchangers economizers, air heaters, condensers, waste-heat boilers, fired heaters, superheaters, and boiler furnaces. Vibration analysis for tube bundles and heat exchangers are also discussed, as are estimating gas-mixture properties at atmospheric and elevated pressures and life-cycle costing techniques. (JMT)

Ganapathy, V.

1982-01-01T23:59:59.000Z

40

Radiant Barriers | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Radiant Barriers Radiant Barriers Radiant Barriers May 30, 2012 - 2:07pm Addthis What does this mean for me? Properly installed radiant barriers can reduce your cooling costs. Radiant barriers are easiest to install in new construction, but can be installed in your existing house, especially if it has an open attic. How does it work? Radiant barriers work by reflecting radiant heat away from living spaces. Radiant barriers are installed in homes -- usually in attics -- primarily to reduce summer heat gain and reduce cooling costs. The barriers consist of a highly reflective material that reflects radiant heat rather than absorbing it. They don't, however, reduce heat conduction like thermal insulation materials. How They Work Heat travels from a warm area to a cool area by a combination of

Note: This page contains sample records for the topic "radiant heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Handbook of radiative heat transfer in high-temperature gases  

Science Conference Proceedings (OSTI)

This work offers both an original method for calculating optical properties of low-temperature plasma at elevated densities ... and an effective new means for calculating radiative heat transfer in hot gases and plasma with arbitrary temperature and pressure distributions. These methods allow for automatic accounting of all details of the plasma spectrum, including the line structure. This volume contains radiant transfer in problems of heat transfer; integration over frequency; methods of partial characteristics; method of effective populations; calculation of partial characteristics; appendix: tabular data.

Soloukhin, R.I.; Golovnev, I.F.; Zamurayev, V.P.; Katsnelson, S.S.; Kovalskaya, G.A.; Sevastyanenko, V.G.; Soloukhin, R.I.

1987-01-01T23:59:59.000Z

42

Heat transfer and heat exchangers reference handbook  

Science Conference Proceedings (OSTI)

The purpose of this handbook is to provide Rocky Flats personnel with an understanding of the basic concepts of heat transfer and the operation of heat exchangers.

Not Available

1991-01-15T23:59:59.000Z

43

Radiant Barriers | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Barriers Barriers Radiant Barriers May 30, 2012 - 2:07pm Addthis What does this mean for me? Properly installed radiant barriers can reduce your cooling costs. Radiant barriers are easiest to install in new construction, but can be installed in your existing house, especially if it has an open attic. How does it work? Radiant barriers work by reflecting radiant heat away from living spaces. Radiant barriers are installed in homes -- usually in attics -- primarily to reduce summer heat gain and reduce cooling costs. The barriers consist of a highly reflective material that reflects radiant heat rather than absorbing it. They don't, however, reduce heat conduction like thermal insulation materials. How They Work Heat travels from a warm area to a cool area by a combination of

44

HEAT TRANSFER METHOD  

DOE Patents (OSTI)

A method is given for increasing burn-out heat fluxes under nucleate boiling conditions in heat exchanger tubes without incurring an increase in pumping power requirements. This increase is achieved by utilizing a spinning flow having a rotational velocity sufficient to produce a centrifugal acceleration of at least 10,000 g at the tube wall. At this acceleration the heat-transfer rate at burn out is nearly twice the rate which can be achieved in a similar tube utilizing axial flow at the same pumping power. At higher accelerations the improvement over axial flow is greater, and heat fluxes in excess of 50 x 10/sup 6/ Btu/hr/sq ft can be achieved.

Gambill, W.R.; Greene, N.D.

1960-08-30T23:59:59.000Z

45

Cooling Energy Measurements of Houses with Attics Containing Radiant Barriers  

E-Print Network (OSTI)

Tests were conducted by Oak Ridge National Laboratory (ORNL) to determine the magnitude of the energy savings brought about by installing radiant barriers in the attics of single-family houses. The radiant barrier used for this test was a product with two reflective aluminum surfaces on a kraft paper base. The radiant barrier has the potential to reduce the radiant heat transfer component impinging on the fiberglass attic insulation. Working as a system in conjunction with an air space, the radiant barrier could theoretically block up to 95% of far-infrared radiation heat transfer. The experiment was conducted in three unoccupied research houses that are operated by ORNL. One house was used as the control house (no barrier was installed), while the other two were used to test the two different methods for installing the radiant barriers. In one house, the barrier was laid on top of the attic fiberglass batt insulation, and in the other house, the barrier was attached to the underside of the roof trusses. The attics of all three houses were insulated with kraft paper faced nominal R-19 fiberglass batt insulation. The results showed a savings in the cooling loads of 21% when the radiant barrier was laid on top of the attic fiberglass insulation and 13% with the radiant barrier attached to the underside of the roof trusses. The savings in electrical consumption was 17% and 9%, respectively. The electrical consumption data and the cooling load data indicated that the most effective way of installing the foil was to lay it on top of the fiberglass batt insulation. The radiant barriers reduced the measured peak ceiling heat fluxes by 39% for the case where the barrier was laid on top of the attic fiberglass insulation. The radiant barrier reduced the integrated heat flows from the attic to house by approximately 30-35% over a 7-day time period.

Levins, W. P.; Karnitz, M. A.; Knight, D. K.

1986-01-01T23:59:59.000Z

46

Heat Transfer Fluids Containing Nanoparticles  

commercial and industrial heat-transfer applications. ... Refrigeration and other cooling systems Nuclear reactors Aerospace Defense Grinding and ...

47

HEAT TRANSFER IN UNDERGROUND HEATING EXPERIMENTS IN GRANITE, STRIPA, SWEDEN  

E-Print Network (OSTI)

Analysis of. Nonlinear Heat Transfer Problems." Report no.Berkeley, Ca. , APPENDIX A. HEAT TRANSFER BY CONDUCTION ANDMeeting, Technical Session on Heat Transfer in Nuclear Waste

Chan, T.

2010-01-01T23:59:59.000Z

48

Heat Transfer Correlation for Finned Casks  

SciTech Connect

Design of finned casks for dissipation of heat from radioactive decay usually requires reliance on generalized correlations in the literature which do not necessarily apply to the specific cask design. A correlation was developed, based on temperature profile measurements, for the design of upright cylindrical casks with vertical fins for convective and radiant heat transfer to ambient air. Temperature data at various heat loads were obtained for two different cask sizes of the same basic design. Each cask is mounted on a steel pallet and contained within a steel mesh cage. The smaller cask, which has 23 fins, has been approved (DOT-SP-6321) for shipment of up to 1400 W (th), and approval is being obtained (AEC AL USA/9503 BLF) for shipment of up to 3500 W heat load in the larger, 60-fin cask. The applicable theoretical equations were fit to the temperature data for both casks by simply adjusting the value used for the number of fins. The resulting correlation provides a reliable method for interpolation and extrapolation and for design of similar finned casks.

Griffin, J. F.

1974-04-01T23:59:59.000Z

49

HEAT TRANSFER IN UNDERGROUND HEATING EXPERIMENTS IN GRANITE, STRIPA, SWEDEN  

E-Print Network (OSTI)

standing of the heat transfer processes associated withto investigate the heat transfer and related processes in an

Chan, T.

2010-01-01T23:59:59.000Z

50

Frame Heat Transfer Research  

NLE Websites -- All DOE Office Websites (Extended Search)

Developing Low-Conductance Window Frames: Capabilities and Developing Low-Conductance Window Frames: Capabilities and Limitations of Current Window Heat Transfer Design Tools Arild Gustavsen 1,* , Dariush Arasteh 2 , Bjørn Petter Jelle 3,4 , Charlie Curcija 5 and Christian Kohler 2 1 Department of Architectural Design, History and Technology, Norwegian University of Science and Technology, Alfred Getz vei 3, NO-7491 Trondheim, Norway 2 Windows and Daylighting Group, Lawrence Berkeley National Laboratory, 1 Cyclotron Road Mail Stop 90R3111, Berkeley, CA 94720- 8134, USA 3 Department of Civil and Transport Engineering, Norwegian University of Science and Technology, Høgskoleringen 7A, NO-7491 Trondheim, Norway 4 Department of Building Materials and Structures, SINTEF Building and Infrastructure, Høgskoleringen 7B,NO-7465 Trondheim, Norway

51

MOLTEN SALT HEAT TRANSFER FLUID  

thermal energy storage tanks Sandia has developed a heat transfer fluid (HTF) for use at elevated temperatures that has a lower freezing point

52

Handbook of heat transfer fundamentals  

SciTech Connect

This handbook is on the fundamentals of heat transfer. It provides coverage on conduction, convection, and radiation and on thermophysical properties of materials.

Rohsenow, W.M.; Hartnett, J.P.; Ganic, E.N.

1985-01-01T23:59:59.000Z

53

Electrohydrodynamically enhanced condensation heat transfer.  

E-Print Network (OSTI)

??In a condenser the thickness of the liquid condensate film covering the cooled surface constitutes a resistance to the heat transfer. By establishing a non… (more)

Wawzyniak, Markus

2012-01-01T23:59:59.000Z

54

Heat Transfer in Complex Fluids  

SciTech Connect

Amongst the most important constitutive relations in Mechanics, when characterizing the behavior of complex materials, one can identify the stress tensor T, the heat flux vector q (related to heat conduction) and the radiant heating (related to the radiation term in the energy equation). Of course, the expression 'complex materials' is not new. In fact, at least since the publication of the paper by Rivlin & Ericksen (1955), who discussed fluids of complexity (Truesdell & Noll, 1992), to the recently published books (Deshpande et al., 2010), the term complex fluids refers in general to fluid-like materials whose response, namely the stress tensor, is 'non-linear' in some fashion. This non-linearity can manifest itself in variety of forms such as memory effects, yield stress, creep or relaxation, normal-stress differences, etc. The emphasis in this chapter, while focusing on the constitutive modeling of complex fluids, is on granular materials (such as coal) and non-linear fluids (such as coal-slurries). One of the main areas of interest in energy related processes, such as power plants, atomization, alternative fuels, etc., is the use of slurries, specifically coal-water or coal-oil slurries, as the primary fuel. Some studies indicate that the viscosity of coal-water mixtures depends not only on the volume fraction of solids, and the mean size and the size distribution of the coal, but also on the shear rate, since the slurry behaves as shear-rate dependent fluid. There are also studies which indicate that preheating the fuel results in better performance, and as a result of such heating, the viscosity changes. Constitutive modeling of these non-linear fluids, commonly referred to as non-Newtonian fluids, has received much attention. Most of the naturally occurring and synthetic fluids are non-linear fluids, for example, polymer melts, suspensions, blood, coal-water slurries, drilling fluids, mud, etc. It should be noted that sometimes these fluids show Newtonian (linear) behavior for a given range of parameters or geometries; there are many empirical or semi-empirical constitutive equations suggested for these fluids. There have also been many non-linear constitutive relations which have been derived based on the techniques of continuum mechanics. The non-linearities oftentimes appear due to higher gradient terms or time derivatives. When thermal and or chemical effects are also important, the (coupled) momentum and energy equations can give rise to a variety of interesting problems, such as instability, for example the phenomenon of double-diffusive convection in a fluid layer. In Conclusion, we have studied the flow of a compressible (density gradient type) non-linear fluid down an inclined plane, subject to radiation boundary condition. The heat transfer is also considered where a source term, similar to the Arrhenius type reaction, is included. The non-dimensional forms of the equations are solved numerically and the competing effects of conduction, dissipation, heat generation and radiation are discussed. It is observed that the velocity increases rapidly in the region near the inclined surface and is slower in the region near the free surface. Since R{sub 7} is a measure of the heat generation due to chemical reaction, when the reaction is frozen (R{sub 7}=0.0) the temperature distributions would depend only on R{sub 1}, and R{sub 2}, representing the effects of the pressure force developed in the material due to the distribution, R{sub 3} and R{sub 4} viscous dissipation, R{sub 5} the normal stress coefficient, R{sub 6} the measure of the emissivity of the particles to the thermal conductivity, etc. When the flow is not frozen (RP{sub 7} > 0) the temperature inside the flow domain is much higher than those at the inclined and free surfaces. As a result, heat is transferred away from the flow toward both the inclined surface and the free surface with a rate that increases as R{sub 7} increases. For a given temperature, an increase in {zeta} implies that the activation energy is smaller and thus, the reaction ra

Mehrdad Massoudi

2012-01-01T23:59:59.000Z

55

Urban Sewage Delivery Heat Transfer System (2): Heat Transfer  

E-Print Network (OSTI)

The thimble delivery heat-transfer (TDHT) system is one of the primary modes to utilize the energy of urban sewage. Using the efficiency-number of transfer units method ( ), the heat-transfer efficiencies of the parallel-flow and reverse-flow TDTH forms are analyzed and the calculation formulas and characteristic are also given. The results indicate that the efficiency of the parallel-flow form is greater than that of the reverse-flow, so the TDTH system must choose the parallel-flow form. The distance-load ratio (DLR) is defined and the minimum DLR is obtained by the technical and economic feasibility analysis. The paper will provide references for heat-transfer calculation and schematic determination of urban sewage cool or heat source applied delivery heat transfer methods.

Zhang, C.; Wu, R.; Li, X.; Li, G.; Zhuang, Z.; Sun, D.

2006-01-01T23:59:59.000Z

56

Radiant vessel auxiliary cooling system  

DOE Patents (OSTI)

In a modular liquid-metal pool breeder reactor, a radiant vessel auxiliary cooling system is disclosed for removing the residual heat resulting from the shutdown of a reactor by a completely passive heat transfer system. A shell surrounds the reactor and containment vessel, separated from the containment vessel by an air passage. Natural circulation of air is provided by air vents at the lower and upper ends of the shell. Longitudinal, radial and inwardly extending fins extend from the shell into the air passage. The fins are heated by radiation from the containment vessel and convect the heat to the circulating air. Residual heat from the primary reactor vessel is transmitted from the reactor vessel through an inert gas plenum to a guard or containment vessel designed to contain any leaking coolant. The containment vessel is conventional and is surrounded by the shell.

Germer, John H. (San Jose, CA)

1987-01-01T23:59:59.000Z

57

Cooling-energy measurements of unoccupied single-family houses with attics containing radiant barriers  

Science Conference Proceedings (OSTI)

Tests were conducted by Oak Ridge National Laboratory (ORNL) to determine the magnitude of the energy savings brought about by installing radiant barriers in the attics of single-family houses. The radiant barrier used for this test is a product with two reflective aluminum surfaces on a kraft paper base. The purpose of the radiant barrier is to reduce the radiant heat transfer component impinging on the fiberglass attic insulation. The radiant barrier works as a system in conjunction with an air space and can theoretically block up to 95% of far-infrared radiation heat transfer. The experiment was conducted in three unoccupied research houses that are operated by ORNL. Two variations on the installation of radiant barriers were studied. One house was used as the control house (no barrier was installed), while the other two were used to test the two different methods for installing the radiant barriers. In one house the barrier was laid on top of the attic fiberglass batt insulation, and in the other house, the barrier was attached to the underside of the roof trusses. The attics of all three houses were insulated with kraft-paper-faced R-19 fiberglass batt insulation. The results showed a savings in the cooling loads of 21% when the radiant barrier was laid on top of the attic fiberglass insulation and 13% with the radiant barrier attached to the underside of the roof trusses. The savings in electrical consumption were 17% and 9%, respectively. The electrical consumption data and the cooling load data indicate that the most effective way of installing the foil is to lay it on top of the fiberglass insulation. The radiant barriers reduced the measured peak ceiling heat fluxes by 39% for the case where the barrier was laid on top of the fiberglass insulation. The radiant barrier reduced the integrated heat flows from the attic to the house by approximately 30 to 35% over a 7-day time period.

Levins, W.P.; Karnitz, M.A.

1986-07-01T23:59:59.000Z

58

HEAT TRANSFER MEANS  

DOE Patents (OSTI)

A heat exchanger is adapted to unifomly cool a spherical surface. Equations for the design of a spherical heat exchanger hav~g tubes with a uniform center-to-center spining are given. The heat exchanger is illustrated in connection with a liquid-fueled reactor.

Fraas, A.P.; Wislicenus, G.F.

1961-07-11T23:59:59.000Z

59

Controlling the Heat Transfer  

Science Conference Proceedings (OSTI)

Through experimental validation that air conduction is shown to be typically the dominant thermal transport mechanism in the contact region, the heat conduction

60

Heat and moisture transfer through clothing  

E-Print Network (OSTI)

R. C. Eberhart (ed), Heat transfer in medicine and biology.Convective and radiative heat transfer coefficients for2008. Study of heat and moisture transfer within multi-layer

Voelker, Conrad; Hoffmann, Sabine; Kornadt, Oliver; Arens, Edward; Zhang, Hui; Huizenga, Charlie

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "radiant heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Heat Transfer Enhancement in Thermoelectric Power Generation.  

E-Print Network (OSTI)

??Heat transfer plays an important role in thermoelectric (TE) power generation because the higher the heat-transfer rate from the hot to the cold side of… (more)

Hu, Shih-yung

2009-01-01T23:59:59.000Z

62

Heating energy measurements of single-family houses with attics containing radiant barriers in combustion with R-11 and R-30 ceiling insulation  

Science Conference Proceedings (OSTI)

Tests were conducted by Oak Ridge National Laboratory to determine the heating energy performance of two levels of fiberglass-batt attic insulation (R-11 and R-30) in combination with truss and horizontally installed radiant barriers. The tests, a continuation of work started in the summer of 1985, were conducted in three unoccupied ranch-style houses in Karns, Tennessee, during the winter of 1986-87. The measured results of the heating tests showed that a horizontal radiant barrier used with R-11 attic insulation reduced the house heating load by 9.3% compared with R-11 with no radiant barrier, while a truss barrier showed essentially no change in the heating load. Horizontal and truss barriers each reduced the heating load by 3.5% when added to R-30 attic insulation. Moisture condensed on the bottom of the horizontal barrier during cold early morning weather but usually dissipated in the warmer afternoon hours at Karns and left no accumulation in the insulation. Depending on the level of attic insulation, an annual heating and cooling HVAC savings ranging from $5 to $65 is estimated to be attainable when a radiant barrier is installed in the attic at Karns. 8 refs., 64 figs., 18 tabs.

Levins, W.P.; Karnitz, M.A.

1988-08-01T23:59:59.000Z

63

Development of a Heat Transfer Model for the Integrated Facade Heating  

E-Print Network (OSTI)

Façade heating is a special application of radiant heating and cooling technology and is used to enhance the indoor comfort level of offices, hotels and museums. Mullion radiators are typically used to implement façade heating. This paper analyzes the heat transfer process of facade heating (mullion radiators) in a pilot research project in Pittsburgh, PA. The heat transfer model for facade heating is developed and verified by measured data. The comparison shows that the heat transfer model predicts the measured temperatures with a root mean squared error (RMSE) of the hot water return temperature, the mullion surface temperature, and the window surface temperature of 0.90°F, 0.98°F and 1.15°F, respectively. The factors which affect the heating capacity of mullion radiators have been analyzed. The analysis shows that the supply water temperature is the primary factor which affects the heating or cooing capacity of window mullions and the mullion surface temperature. Return water temperature and mullion surface temperature are quasi-linear functions often water supply temperature. Mullion surface temperature, indoor air temperature gradient on the glazing surface within one foot from mullions is much higher than in the central part of the window. The temperatures in the central 2 feet of a 4-foot window show almost no influence by the mullion surface temperature. Also, the conductive thermal resistance of the mullion double tubes with fillings between two tubes plays a decisive role in controlling the mullion and window frame temperatures.

Gong, X.; Archer, D. H.; Claridge, D. E.

2007-01-01T23:59:59.000Z

64

Enhanced heat transfer using nanofluids  

DOE Patents (OSTI)

This invention is directed to a method of and apparatus for enhancing heat transfer in fluids such as deionized water. ethylene glycol, or oil by dispersing nanocrystalline particles of substances such as copper, copper oxide, aluminum oxide, or the like in the fluids. Nanocrystalline particles are produced and dispersed in the fluid by heating the substance to be dispersed in a vacuum while passing a thin film of the fluid near the heated substance. The fluid is cooled to control its vapor pressure.

Choi, Stephen U. S. (Lisle, IL); Eastman, Jeffrey A. (Naperville, IL)

2001-01-01T23:59:59.000Z

65

Influence of Dust on the Emissivity of Radiant Barriers  

E-Print Network (OSTI)

A model of the radiant heat transfer in attics containing dusty radiant barriers was developed. The geometrical model was a triangular enclosure in which the temperatures of the enclosing surfaces were known. The dust particles were simulated as areas of diameter equal to the mean diameter of the real dust to be analyzed and an emissivity substantially larger than the emissivity of the radiant barrier. Several shape factors were calculated using shape factor algebra, including a procedure to find the shape factor between a small rectangle and a triangular surface perpendicular to the rectangular plane. The thermal model was developed using the "Net Radiation Method" in which the net heat exchange between the surfaces surrounding the enclosure was found by solving a system of equations that has as many equations as the number of surfaces involved in the calculations. This led to the necessity of solving a very large system of equations in order to account for the dust particles in a representative amount. The solution of the system of equations provided the heat flux for each element of the enclosure. Finally, replacing the radiant barrier and the dust particles for an equivalent surface corresponding to the dusty radiant barrier provided the means to calculate the emissivity of this dusty radiant barrier. The theoretical model was tested to assess its validity. The experimentation was carried out using a reflection emissometer to measure the increase of the emissivity of aluminum radiant barrier when known quantities of dust were artificially applied to it. The experimental results showed good agreement with the theoretical model. A linear relationship between the emissivity and the area of dust coverage was found. The simple relation developed can be used in future research which still has to deal with the determination of the area of dust coverage by using the geometrical model of dust superposition or other statistical model to simulate the random location of random size dust particles over the radiant barrier.

Noboa, Homero L.

1991-12-01T23:59:59.000Z

66

Nanoscale heat transfer - from computation to experiment  

E-Print Network (OSTI)

Heat transfer can differ distinctly at the nanoscale from that at the macroscale. Recent advancement in

Luo, Tengfei

2013-04-09T23:59:59.000Z

67

Performance Testing of Radiant Barriers  

E-Print Network (OSTI)

TVA has conducted a study to determine the effects of radiant barriers (RBI (i.e., material with a low emissivity surface facing an air space), when used with fiberglass, on attic heat transfer during summer and winter. This study employed five small test cells exposed to ambient conditions and having attics with gable and soffit vents. Three different RB configurations were tested and compared to the non-RR configuration. Heat flux transducers determined the heat transfer between the attic and conditioned space. The results showed that all RB con figurations significantly reduced heat gain through the ceiling during the summer. Reductions in heat gain during daylight and peak electric load hours were especially attractive. Roof temperatures for the RB configurations were only slightly higher than for the non-RB case. Heat transfer reductions for the RB configurations in the winter were smaller than those for the summer but were still significant in many, but not all, situations. Savings during night and peak electric load hours were especially attractive.

Hall, J. A.

1986-01-01T23:59:59.000Z

68

Optimization of Phase Change Heat Transfer in Biporous Media  

E-Print Network (OSTI)

Aspectcs of Boiling Heat Transfer”. PhD Thesis dissertation,Celled Foams”. Numerical Heat Transfer, Vol. 54, issue 1,Dimensional Fluid Flow and Heat Transfer”. Numerical Heat

Reilly, Sean

2013-01-01T23:59:59.000Z

69

Influence of Infrared Radiation on Attic Heat Transfer  

E-Print Network (OSTI)

An experimental study concerned with different modes of heal transfer in fibrous and cellulose insulating material is presented. A series of experiments were conducted using an attic simulator to determine the effects of ventilation on attic heat transfer, and the effect of infrared radiation on the thermal conductivity of the insulation system and on attic heat transfer. All the tests were performed at steady state conditions by controlling the roof deck temperature. Calculations are performed for insulation thicknesses between 1 inch (2.54cm) and 6.0 inches (15.24cm) and roof deck temperatures between 145°F (62.78°C) and 100°F (36.78°C). The temperature profiles within the insulation were measured by placing thermocouples at various levels within the insulation. The profiles for the cellulose insulation are linear. The profiles within the glass fiber insulation are non-linear due to the effect of infrared radiation. Also heat fluxes were measured through different insulation thicknesses and for different roof temperatures. It was found that a radiant barrier such as aluminum foil can reduce the heat flux significantly. Experimental results were compared to a Three-Region approximate solution developed at Oak Ridge National Laboratories (ORNL). The model was in good agreement with experimental results.

Katipamula, S.; Turner, W. D.; Murphy, W. E.; O'Neal, D. L.

1985-01-01T23:59:59.000Z

70

Heat Flow, Heat Transfer And Lithosphere Rheology In Geothermal...  

Open Energy Info (EERE)

Flow, Heat Transfer And Lithosphere Rheology In Geothermal Areas- Features And Examples Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Heat Flow,...

71

Technical evaluation of a solar heating system having conventional hydronic solar collectors and a radiant panel slab. Final report  

DOE Green Energy (OSTI)

A simple innovative solar heating design (Solar Option One) using conventional hydronic solar collectors and a radiant panel slab was constructed. An objective of hybrid solar design is to combine the relative advantages of active and passive design approaches while minimizing their respective disadvantages. A test house using the Solar Option One heating system was experimentally monitored to determine its energy based performance during the 1982-83 heating season. The test residence is located in Lyndonville, Vermont, an area which has a characteristically cold and cloudy climate. The two story residence has a floor area of about 1400 square feet and is constructed on a 720 square foot 5.5 inch thick floor slab. A 24 inch packed gravel bed is located beneath the slab and the slab-gravel bed is insulated by two inches of polystyrene insulation. The test building is of frame construction and uses insulation levels which have become commonplace throughout the country. The structure would not fall into the superinsulated category but was tightly constructed so as to have a low infiltration level. The building is sun-tempered in that windows were concentrated somewhat on the South side and all but avoided on the North. A solar greenhouse on the South side of the building was closed off from the structure permanently throughout the testing so as to better observe the solar heating invention without confounding variables. The monitoring equipment generated an internal gain of about 17,000 BTUs per day, roughly the equivalent of occupancy by two persons. A full description of the experimental testing program is given. System efficiency and performance are reported.

Starr, R.J.

1984-04-01T23:59:59.000Z

72

Available Technologies: Heat Transfer Interface for Thermo ...  

Refrigeration systems; Internal combustion engines; ... The components of the technology could be used to improve heat transfer in industrial, ...

73

Heat Transfer & Alternative Energy Systems Group Staff ...  

Science Conference Proceedings (OSTI)

Heat Transfer and Alternative Energy Systems Group Staff. Staff Listing. Dr. William M. Healy, Leader, Supervisory Mechanical ...

2013-08-07T23:59:59.000Z

74

Acoustically Enhanced Boiling Heat Transfer  

E-Print Network (OSTI)

An acoustic field is used to increase the critical heat flux (CHF) of a flat-boiling-heat-transfer surface. The increase is a result of the acoustic effects on the vapor bubbles. Experiments are performed to explore the effects of an acoustic field on vapor bubbles in the vicinity of a rigid-heated wall. Work includes the construction of a novel heater used to produce a single vapor bubble of a prescribed size and at a prescribed location on a flatboiling surface for better study of an individual vapor bubble's reaction to the acoustic field. Work also includes application of the results from the single-bubble heater to a calibrated-copper heater used for quantifying the improvements in CHF.

Z. W. Douglas; M. K. Smith; A. Glezer

2008-01-07T23:59:59.000Z

75

Topic 14. Retrofit and optimal operation of the building energy systems Performances of Low Temperature Radiant Heating Systems  

E-Print Network (OSTI)

panel system are given by its energy (the consumption of gas for heating, electricity for pumps for residential buildings are increasingly used. According to some studies, this figure exceeds 50% (Kilkis et al of new calculation methods. However, in terms of heat transfer modelling, there are several analytical

Paris-Sud XI, Université de

76

Heat transfer via dropwise condensation on hydrophobic microstructured surfaces  

E-Print Network (OSTI)

Dropwise condensation has the potential to greatly increase heat transfer rates. Heat transfer coefficients by dropwise condensation and film condensation on microstructured silicon chips were compared. Heat transfer ...

Ruleman, Karlen E. (Karlen Elizabeth)

2009-01-01T23:59:59.000Z

77

Heat exchanger device and method for heat removal or transfer  

Science Conference Proceedings (OSTI)

Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.

Koplow, Jeffrey P. (San Ramon, CA)

2012-07-24T23:59:59.000Z

78

Handbook of heat transfer applications (2nd edition)  

Science Conference Proceedings (OSTI)

The applications of heat transfer in engineering problems are considered. Among the applications discussed are: mass transfer cooling; heat exchangers; and heat pipes. Consideration is also given to: heat transfer in nonNewtonian fluids; fluidized and packed beds; thermal energy storage; and heat transfer in solar collectors. Additional topics include: heat transfer in buildings; cooling towers and ponds; and geothermal heat transfer.

Rohsenow, W.M.; Hartnett, J.P.; Ganic, E.N.

1985-01-01T23:59:59.000Z

79

Air-to-Water Heat Pumps With Radiant Delivery in Low-Load Homes  

SciTech Connect

Space conditioning represents nearly 50% of average residential household energy consumption, highlighting the need to identify alternative cost-effective, energy-efficient cooling and heating strategies. As homes are better built, there is an increasing need for strategies that are particularly well suited for high performance, low load homes. ARBI researchers worked with two test homes in hot-dry climates to evaluate the in-situ performance of air-to-water heat pump (AWHP) systems, an energy efficient space conditioning solution designed to cost-effectively provide comfort in homes with efficient, safe, and durable operation. Two monitoring projects of test houses in hot-dry climates were initiated in 2010 to test this system. Both systems were fully instrumented and have been monitored over one year to capture complete performance data over the cooling and heating seasons. Results are used to quantify energy savings, cost-effectiveness, and system performance using different operating modes and strategies. A calibrated TRNSYS model was developed and used to evaluate performance in various climate regions. This strategy is most effective in tight, insulated homes with high levels of thermal mass (i.e. exposed slab floors).

Backman, C.; German, A.; Dakin, B.; Springer, D.

2013-12-01T23:59:59.000Z

80

Heat transfer pathways in underfloor air distribution (UFAD) systems  

E-Print Network (OSTI)

the following heat transfer processes: conduction throughtudes of the major heat transfer processes in a typical room

Bauman, F.; Jin, H.; Webster, T.

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "radiant heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Heat Flow, Heat Transfer And Lithosphere Rheology In Geothermal Areas-  

Open Energy Info (EERE)

Flow, Heat Transfer And Lithosphere Rheology In Geothermal Areas- Flow, Heat Transfer And Lithosphere Rheology In Geothermal Areas- Features And Examples Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Heat Flow, Heat Transfer And Lithosphere Rheology In Geothermal Areas- Features And Examples Details Activities (5) Areas (5) Regions (0) Abstract: Surface heat flow measurements over active geothermal systems indicate strongly positive thermal anomalies. Whereas in "normal" geothermal settings, the surface heat flow is usually below 100-120 mW m- 2, in active geothermal areas heat flow values as high as several watts per meter squared can be found. Systematic interpretation of heat flow patterns sheds light on heat transfer mechanisms at depth on different lateral, depth and time scales. Borehole temperature profiles in active geothermal

82

Enhanced heat transfer for thermionic power modules  

DOE Green Energy (OSTI)

The thermionic power module is capable of operating at very high heat fluxes, which in turn serve to reduce capital costs. The most efficient operation also requires uniform heat fluxes. The development of enhanced heat transfer systems is required to meet the demand for high heat fluxes (>20 w/cm/sup 2/) at high temperatures (>1500K) which advanced thermionic power modules place upon combustion systems. Energy transfer from the hot combustion gases may take place by convection, radiation, or a combination of radiation and convection. Enhanced convective heat transfer with a jet impingement system has been demonstrated in a thermionic converter. The recently-developed cellular ceramic radiative heat transfer system has also been applied to a thermionic converter. By comparing the jet impingement and cellular ceramic radiative heat transfer systems, an appropriate system may be selected for utilization in advanced thermionic power modules. Results are reported.

Johnson, D.C.

1981-07-01T23:59:59.000Z

83

Heat Transfer In Turbine Mid Structures.  

E-Print Network (OSTI)

??In order to estimate the life time of a cooled gas turbine component, knowledge of the heat transfer is essential in order to predict the… (more)

Abou-Taouk, Abdallah

2006-01-01T23:59:59.000Z

84

Enhanced Heat Transfer in Composite Materials.  

E-Print Network (OSTI)

??Many composite materials are composed of a matrix reinforced with fibers. Carbon fiber composites are currently being used for high heat transfer applications. Carbon fibers… (more)

Pathak, Sayali V.

2013-01-01T23:59:59.000Z

85

Interface Heat Transfer Effects for Solidification Processes  

Science Conference Proceedings (OSTI)

The solidification rate of a casting is governed by the rate of heat extraction, which in turn is dominated by the rate of heat transfer across the casting-mold ...

86

HEAT EXCHANGER DEVICE AND METHOD FOR HEAT REMOVAL OR TRANSFER ...  

Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a ...

87

Low heat transfer, high strength window materials  

DOE Patents (OSTI)

A multi-pane window with improved insulating qualities; comprising a plurality of transparent or translucent panes held in an essentially parallel, spaced-apart relationship by a frame. Between at least one pair of panes is a convection defeating means comprising an array of parallel slats or cells so designed as to prevent convection currents from developing in the space between the two panes. The convection defeating structures may have reflective surfaces so as to improve the collection and transmittance of the incident radiant energy. These same means may be used to control (increase or decrease) the transmittance of solar energy as well as to decouple the radiative transfer between the interior surfaces of the transparent panes.

Berlad, Abraham L. (Stony Brook, NY); Salzano, Francis J. (Patchogue, NY); Batey, John E. (Stony Brook, NY)

1978-01-01T23:59:59.000Z

88

Heat Transfer Characteristics of a Generalized Divided Flow Heat Exchanger  

E-Print Network (OSTI)

The concept of a "Divided-flow" heat exchanger is generalized by locating the shell inlet (or outlet) nozzle off-center such that the two shell sub-streams are unequal and traverse unequal flow paths. The governing equations for heat transfer in such an exchanger are derived and solved leading to an optimization problem. In this problem, the optimal subdivision of heat transfer surface to minimize required overall heat transfer surface, under certain restricted conditions, is sought. It is shown that the off-center nozzle location can be selected judiciously so as to maintain (or even improve heat transfer) while reducing the gross shellside pressure loss. Thus, the pumping costs are minimized without sacrificing heat transfer.

Singh, K. P.

1979-01-01T23:59:59.000Z

89

Containment condensing heat transfer. [PWR; BWR  

SciTech Connect

This report presents a mechanistic heat-transfer model that is valid for large scale containment heat sinks. The model development is based on the determination that the condensation is controlled by mass diffusion through the vapor-air boundary layer, and the application of the classic Reynolds' analogy to formulate expressions for the transfer of heat and mass based on hydrodynamic measurements of the momentum transfer. As a result, the analysis depends on the quantification of the shear stress (momentum transfer) at the interface between the condensate film and the vapor-air boundary layer. In addition, the currently used Tagami and Uchida test observations and their range of applicability are explained.

Gido, R.G.; Koestel, A.

1983-01-01T23:59:59.000Z

90

Radiative heat transfer between dielectric bodies  

E-Print Network (OSTI)

The recent development of a scanning thermal microscope (SThM) has led to measurements of radiative heat transfer between a heated sensor and a cooled sample down to the nanometer range. This allows for comparision of the known theoretical description of radiative heat transfer, which is based on fluctuating electrodynamics, with experiment. The theory itself is a macroscopic theory, which can be expected to break down at distances much smaller than 10-8m. Against this background it seems to be reasonable to revisit the known macroscopic theory of fluctuating electrodynamics and of radiative heat transfer.

Svend-Age Biehs

2011-03-16T23:59:59.000Z

91

"Nanotechnology Enabled Advanced Industrial Heat Transfer Fluids"  

DOE Green Energy (OSTI)

ABSTRACT Nanotechnology Enabled Advanced industrial Heat Transfer Fluids” Improving the efficiency of Industrial Heat Exchangers offers a great opportunity to improve overall process efficiencies in diverse industries such as pharmaceutical, materials manufacturing and food processing. The higher efficiencies can come in part from improved heat transfer during both cooling and heating of the material being processed. Additionally, there is great interest in enhancing the performance and reducing the weight of heat exchangers used in automotives in order to increase fuel efficiency. The goal of the Phase I program was to develop nanoparticle containing heat transfer fluids (e.g., antifreeze, water, silicone and hydrocarbon-based oils) that are used in transportation and in the chemical industry for heating, cooling and recovering waste heat. Much work has been done to date at investigating the potential use of nanoparticle-enhanced thermal fluids to improve heat transfer in heat exchangers. In most cases the effect in a commercial heat transfer fluid has been marginal at best. In the Phase I work, we demonstrated that the thermal conductivity, and hence heat transfer, of a fluid containing nanoparticles can be dramatically increased when subjected to an external influence. The increase in thermal conductivity was significantly larger than what is predicted by commonly used thermal models for two-phase materials. Additionally, the surface of the nanoparticles was engineered so as to have a minimal influence on the viscosity of the fluid. As a result, a nanoparticle-laden fluid was successfully developed that can lead to enhanced heat transfer in both industrial and automotive heat exchangers

Dr. Ganesh Skandan; Dr. Amit Singhal; Mr. Kenneth Eberts; Mr. Damian Sobrevilla; Prof. Jerry Shan; Stephen Tse; Toby Rossmann

2008-06-12T23:59:59.000Z

92

Influence of Attic Radiant Barrier Systems on Air Conditioning Demand in an Utility Pilot Project  

E-Print Network (OSTI)

A utility monitoring project has evaluated radiant barrier systems (RBS) as a new potential demand site management (DSM) program. The study examined how the retrofit of attic radiant barriers can be expected to alter utility residential space conditioning loads. An RBS consists of a layer of aluminum foil fastened to roof decking or roof trusses to block radiant heat transfer between the hot roof surface and the attic below. The radiant barrier can significantly lower summer heat transfer to the attic insulation and to the cooling duct system. Both of these mechanisms have strong potential impacts on cooling energy use as illustrated in Figures 1 and 2. The pilot project involved installation of RBS in nine homes that had been extensively monitored over the preceding year. The houses varied in conditioned floor area from 939 to 2,440 square feet; attic insulation varied from R-9 to R-30. The homes had shingle roofs with varying degrees of attic ventilation. The radiant barriers were installed during the summer of 2000. Data analysis on the pre and post cooling and heating consumption was used to determine impacts on energy use and peak demand for the utility. The average cooling energy savings from the RBS retrofit was 3.6 kWh/day, or about 9%. The average reduction in summer afternoon peak demand was 420 watts (or about 16%).

Parker, D. S.; Sherwin, J. R.

2002-01-01T23:59:59.000Z

93

Heat Transfer Enhancement: Second Generation Technology  

E-Print Network (OSTI)

This paper reviews current activity in the field of enhanced heat transfer, with the aim of illustrating the technology and typical applications. Guidelines for application of enhanced surfaces are given, and practical concerns and economics are discussed. Special attention is directed toward use of enhanced surfaces in industrial process heat exchangers and heat recovery equipment.

Bergles, A. E.; Webb, R. L.

1984-01-01T23:59:59.000Z

94

Fundamental heat transfer experiments of heat pipes for turbine cooling  

SciTech Connect

Fundamental heat transfer experiments were carried out for three kinds of heat pipes that may be applied to turbine cooling in future aero-engines. In the turbine cooling system with a heat pipe, heat transfer rate and start-up time of the heat pipe are the most important performance criteria to evaluate and compare with conventional cooling methods. Three heat pipes are considered, called heat pipe A, B, and C, respectively. All heat pipes have a stainless steel shell and nickel sintered powder metal wick. Sodium (Na) was the working fluid for heat pipes A and B; heat pipe C used eutectic sodium-potassium (NaK). Heat pipes B and C included noncondensible gas for rapid start-up. There were fins on the cooling section of heat pipes. In the experiments, an infrared image furnace supplied heat to the heat pipe simulating turbine blade surface conditions. In the results, heat pipe B demonstrated the highest heat flux of 17 to 20 W/cm{sup 2}. The start-up time was about 6 minutes for heat pipe B and about 6 minutes for heat pipe A. Thus, adding noncondensible gas effectively reduced start-up time. Although NaK is a liquid phase at room temperature, the start-up time of heat pipe C (about 7 to 8 minutes) was not shorter than the heat pipe B. The effect of a gravitational force on heat pipe performance was also estimated by inclining the heat pipe at an angle of 90 deg. There was no significant gravitational dependence on heat transport for heat pipes including noncondensible gas.

Yamawaki, S. [Ishikawajima-Harima Heavy Industries Co., Ltd., Tokyo (Japan); Yoshida, T.; Taki, M.; Mimura, F. [National Aerospace Lab., Tokyo (Japan)

1998-07-01T23:59:59.000Z

95

Dynamics of heat transfer between nano systems  

E-Print Network (OSTI)

We develop a dynamical theory of heat transfer between two nano systems. In particular, we consider the resonant heat transfer between two nanoparticles due to the coupling of localized surface modes having a finite spectral width. We model the coupled nanosystem by two coupled quantum mechanical oscillators, each interacting with its own heat bath, and obtain a master equation for the dynamics of heat transfer. The damping rates in the master equation are related to the lifetimes of localized plasmons in the nanoparticles. We study the dynamics towards the steady state and establish connection with the standard theory of heat transfer in steady state. For strongly coupled nano particles we predict Rabi oscillations in the mean occupation number of surface plasmons in each nano particle.

Svend-Age Biehs; Girish S. Agarwal

2012-10-18T23:59:59.000Z

96

Passive heat transfer means for nuclear reactors  

DOE Patents (OSTI)

An improved passive cooling arrangement is disclosed for maintaining adjacent or related components of a nuclear reactor within specified temperature differences. Specifically, heat pipes are operatively interposed between the components, with the vaporizing section of the heat pipe proximate the hot component operable to cool it and the primary condensing section of the heat pipe proximate the other and cooler component operable to heat it. Each heat pipe further has a secondary condensing section that is located outwardly beyond the reactor confinement and in a secondary heat sink, such as air ambient the containment, that is cooler than the other reactor component. Means such as shrouding normally isolated the secondary condensing section from effective heat transfer with the heat sink, but a sensor responds to overheat conditions of the reactor to open the shrouding, which thereby increases the cooling capacity of the heat pipe. By having many such heat pipes, an emergency passive cooling system is defined that is operative without electrical power.

Burelbach, James P. (Glen Ellyn, IL)

1984-01-01T23:59:59.000Z

97

Heat transfer pathways in underfloor air distribution (UFAD) systems  

E-Print Network (OSTI)

permission. QC-06-053 Heat Transfer Pathways in Underfloorchange the dynamics of heat transfer within a room as wellchange the dynamics of heat transfer within a room as well

Bauman, F.; Jin, H.; Webster, T.

2006-01-01T23:59:59.000Z

98

AN EXPERIMENTAL AND THEORETICAL STUDY OF HEAT TRANSFER WITH COMBUSTION  

E-Print Network (OSTI)

Figure 7.6. Thin film heat transfer gauge. I I il j i II· Figure 2. 2. Thin 1m heat transfer gauge. 'l' :i t jt IIIII. MEASUREMENTS AND HEAT TRANSFER IN THE SOLID Experiments

Heperkan, Hasan A.

2013-01-01T23:59:59.000Z

99

Clean Boiler Waterside Heat Transfer Surfaces  

SciTech Connect

This revised ITP tip sheet on cleaning boiler water-side heat transfer surfaces provides how-to advice for improving industrial steam systems using low-cost, proven practices and technologies.

2006-01-01T23:59:59.000Z

100

Nonequilibrium Electromagnetic Fluctuations: Heat Transfer and Interactions  

E-Print Network (OSTI)

The Casimir force between arbitrary objects in equilibrium is related to scattering from individual bodies. We extend this approach to heat transfer and Casimir forces in nonequilibrium cases where each body, and the ...

Kruger, Matthias

Note: This page contains sample records for the topic "radiant heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Daytime heat transfer processes over mountainous terrain  

Science Conference Proceedings (OSTI)

The daytime heat transfer mechanisms over mountainous terrain are investigated by means of large-eddy simulations over idealized valleys. Two- and three-dimensional topographies, corresponding to infinite and finite valleys, are used in order to ...

Juerg Schmidli

102

NEWTON: Greenhouse Gas and Heat Transfer  

NLE Websites -- All DOE Office Websites (Extended Search)

Greenhouse Gas and Heat Transfer Greenhouse Gas and Heat Transfer Name: Robert Status: teacher Grade: 9-12 Location: AK Country: USA Date: Summer 2013 Question: It would appear from a superficial reading that heat flows out of a greenhouse gas more slowly than heat flows into the same gas. This has to be an incorrect interpretation. It seems more likely that molecules with high heat capacities resist heat transfer-both into and out of such a molecular system. At a molecular level how does heat move out of a hot greenhouse gas? I have seen plots of Cv vs Tempt which indicates that heat moves from translational modes of motion-into rotational modes and finally into modes of vibration. The energy spacing of vibrations is generally grater that rotation which are greater than translation. Could it be that it is this quantization of the energy levels and the difference in energy between such quantum states that is the source of the resistance to heat flow or transfer?

103

Development and Demonstration of a High Efficiency, Rapid Heating, Low NOx Alternative to Conventional Heating of Round Steel Shapes, Steel Substrate (Strip) and Coil Box Transfer Bars  

SciTech Connect

Direct Flame Impingement involves the use of an array of very high-velocity flame jets impinging on a work piece to rapidly heat the work piece. The predominant mode of heat transfer is convection. Because of the locally high rate of heat transfer at the surface of the work piece, the refractory walls and exhaust gases of a DFI furnace are significantly cooler than in conventional radiant heating furnaces, resulting in high thermal efficiency and low NOx emissions. A DFI furnace is composed of a successive arrangement of heating modules through or by which the work piece is conveyed, and can be configured for square, round, flat, and curved metal shapes (e.g., billets, tubes, flat bars, and coiled bars) in single- or multi-stranded applications.

Kurek, Harry; Wagner, John

2010-01-25T23:59:59.000Z

104

Economic Evaluation of Insulation/Radiant Barrier Systems for the State of Texas  

E-Print Network (OSTI)

This paper presents simulated performance of insulation/radiant barrier systems under different Texas climates. A transient heat and mass transfer model which predicts thermal performance of residential attics (Medina, 1992) was coupled with an "economic" subroutine. Simple payback periods were estimated which were based on current insulation and radiant barrier (RB) prices (materials and installation), and current and forecast electric rates. It was found that when the analyses were based solely on reductions of ceiling heat loads during the summer time, a combination of R-11 with RB was more effective than upgrading the insulation level to R-19. Similarly, adding a radiant barrier to an existing insulation level of R-19 proved more effective than upgrading to R-30. When heat gains to the cold air traveling inside A/C ducts (\\which are usually installed in attic spaces) were considered, all insulation/radiant barrier combinations showed faster payback periods than insulation upgrades, During the winter time, insulation upgrades proved to be more effective than insulation/radiant barrier combinations. The simple payback analyses presented herein include both summer and winter simulations.

Medina, M. A.; Turner, W. D.; O'Neal, D. L.

1994-01-01T23:59:59.000Z

105

Analysis of Heat Transfer in Metal Hydride Based Hydrogen Separation  

DOE Green Energy (OSTI)

This thesis presents a transient heat transfer analysis to model the heat transfer in the Pd/k packed column, and the impact of adding metallic foam.

Fleming, W.H. Jr.

1999-10-20T23:59:59.000Z

106

Aerodynamic Losses and Heat Transfer in a Blade Cascade with...  

NLE Websites -- All DOE Office Websites (Extended Search)

Aerodynamic Losses and Heat Transfer in a Aerodynamic Losses and Heat Transfer in a Blade Cascade with 3 Blade Cascade with 3 - - D D Endwall Endwall Contouring Contouring...

107

Experimental study on turbulent natural convection heat transfer in ...  

Science Conference Proceedings (OSTI)

Feb 16, 2010 ... ments are conducted to investigate flow and heat transfer ... turbulent region, the heat transfer deterioration occurs for a bubble flow rate Q = 33 ...

108

Heat transfer via dropwise condensation on hydrophobic microstructured surfaces.  

E-Print Network (OSTI)

??Dropwise condensation has the potential to greatly increase heat transfer rates. Heat transfer coefficients by dropwise condensation and film condensation on microstructured silicon chips were… (more)

Ruleman, Karlen E. (Karlen Elizabeth)

2009-01-01T23:59:59.000Z

109

Characterization and Development of Advanced Heat Transfer Technologies (Presentation)  

DOE Green Energy (OSTI)

Advancing heat transfer technologies is a critical factor in power electronics equipment. NREL aims to characterize and develop advanced heat transfer technologies.

Abraham, T.

2007-11-08T23:59:59.000Z

110

Heat transfer in excimer laser melting of thin polysilicon layers  

NLE Websites -- All DOE Office Websites (Extended Search)

Heat transfer in excimer laser melting of thin polysilicon layers Title Heat transfer in excimer laser melting of thin polysilicon layers Publication Type Journal Article Year of...

111

Modeling of Heat Transfer in Geothermal Heat Exchangers  

E-Print Network (OSTI)

Ground-coupled heat pump (GCHP) systems have been gaining increasing popularity for space conditioning in residential and commercial buildings. The geothermal heat exchanger (GHE) is devised for extraction or injection of thermal energy from/into the ground. This paper summarizes the authors' studies on heat transfer in ground-coupled heat pump systems. Taking the fluid axial convective heat transfer and thermal “short-circuiting” among U-tube legs into account, a quasi-3-D model has been solved for heat transfer inside boreholes. The transient 2-D temperature response in a semi-infinite medium with a line-source of finite length has also been derived for heat conduction outside boreholes. In order to investigate the impact of groundwater advection on the performance of ground heat exchangers, an analytical solution is obtained for a line heat source in an infinite porous medium with groundwater advection. These explicit expressions have more solid theoretical basis, and can be easily incorporated into computer programs for thermal analysis and engineering design of ground heat exchangers.

Cui, P.; Man, Y.; Fang, Z.

2006-01-01T23:59:59.000Z

112

FILM COOLING CALCULATIONS WITH AN ITERATIVE CONJUGATE HEAT TRANSFER APPROACH USING EMPIRICAL HEAT TRANSFER COEFFICIENT CORRECTIONS.  

E-Print Network (OSTI)

??An iterative conjugate heat transfer technique was developed and automated to predict the temperatures on film cooled surfaces such as flat plates and turbine blades.… (more)

Dhiman, Sushant

2010-01-01T23:59:59.000Z

113

Nonequilibrium Electromagnetic Fluctuations: Heat Transfer and Interactions  

Science Conference Proceedings (OSTI)

The Casimir force between arbitrary objects in equilibrium is related to scattering from individual bodies. We extend this approach to heat transfer and Casimir forces in nonequilibrium cases where each body, and the environment, is at a different temperature. The formalism tracks the radiation from each body and its scatterings by the other objects. We discuss the radiation from a cylinder, emphasizing its polarized nature, and obtain the heat transfer between a sphere and a plate, demonstrating the validity of proximity transfer approximation at close separations and arbitrary temperatures.

Krueger, Matthias; Kardar, Mehran [Massachusetts Institute of Technology, Department of Physics, Cambridge, Massachusetts 02139 (United States); Emig, Thorsten [Laboratoire de Physique Theorique et Modeles Statistiques, CNRS UMR 8626, Ba circumflex timent 100, Universite Paris-Sud, 91405 Orsay cedex (France)

2011-05-27T23:59:59.000Z

114

Analysis in Support of the Radiant Barrier Fact Sheet 2010 Update  

Science Conference Proceedings (OSTI)

Quantifying the benefits of radiant barriers is complex because the benefits depend upon the climate, attic geometry, duct arrangements, and other building parameters. Homeowners, however, require simplified guidance regarding building envelope options, even those options that seem to have no simple answers. An extensive parametric evaluation of radiant barrier installation alternatives was made using a newly expanded and benchmarked version of an attic simulation program. To complement this anal- ysis, a detailed numerical analysis of radiation heat transfer within the attic and within the small space bounded by the rafters and the sheathing was completed. The results provide guidance for homeowners and builders.

Stovall, Therese K [ORNL; Shrestha, Som S [ORNL; Arimilli, Rao V [ORNL; Yarbrough, David W [ORNL; Pearson, Thomas [ASHRAE, Student Member

2010-01-01T23:59:59.000Z

115

Electrically heated liquid tank employing heat pipe heat transfer means  

SciTech Connect

The heating apparatus for applying heat to the interior of a chamber includes a modular, removable, electrical, heat-producing unit and a heat pipe mountable in a wall of the chamber with one end of the pipe arranged to receive heat from the electrical heat producing unit exterior of the housing and with another end of the pipe constructed and arranged to apply heat to the medium within the chamber. The heat pipe has high conductivity with a low temperature differential between the ends thereof and the heat producing unit includes an electric coil positioned about and removably secured to the one end of the heat pipe. The electric coil is embedded in a high thermal conducitivity, low electrical conductivity filler material which is surrounded by a low thermal conductivity insulating jacket and which is received around a metal core member which is removably secured to the one end of the heat pipe.

Shutt, J.R.

1978-12-26T23:59:59.000Z

116

Handbook of heat and mass transfer. Volume 1  

Science Conference Proceedings (OSTI)

This two-volume series, the work of more than 100 contributors, presents advanced topics in industrial heat and mass transfer operations and reactor design technology. Volume 1 emphasizes heat transfer operations. The contents are: Fundamentsls of momentum and heat transfer. Scaling in laminar and turbulent heat and mass transfer. Heat flux in the Benar-Rayleigh problem. Hydrodynamics of free liquid jets and their influence on heat transfer. Natural convection heat transfer to power law fluids. Natural convection in evaporating droplets. Principles of heat and mass transfer with liquid evaporation. Bubble nucleation, growth, and departure in boiling heat transfer. Forced convection boiling in uniformly heated channels. Transient boiling heat transfer under forced convection. Prediction of heat transfer during forced convection subcooled boiling. Liquid metal heat transfer in turbulent pipe flows. Mixed convection in buoyant plumes. Nucleation and growth in the diffusion cloud chamber. Convective and radiative heat transfer of flowing gaseous-solid suspensions. Heat transfer in gas-solid fluidized beds. Gas convection and unsteady conduction in fluid bed heat transfer. Heat transfer between tubes and gas-solid fluid beds. Periodic heat transfer through inhomogeneous layers.

Cheremisinoff, N.P.

1986-01-01T23:59:59.000Z

117

Heat transfer 1990. Proceedings of the ninth international heat transfer conference  

Science Conference Proceedings (OSTI)

This book contains the proceedings of the Ninth International Heat Transfer Conference. Included in Volume 6 are the following chapters: Local void fraction measurements in finned tube bundles, Unsteady heat and mass transfer in low two-phase flows and The effect of physical properties on drop size in annular flow.

Hetsroni, G.

1990-01-01T23:59:59.000Z

118

Handbook of numerical heat transfer  

Science Conference Proceedings (OSTI)

A comprehensive presentation is given of virtually all numerical methods that are suitable for the analysis of the various heat transverse and fluid flow problems that occur in research, practice, and university instruction. After reviewing basic methodologies, the following topics are covered: finite difference and finite element methods for parabolic, elliptic, and hyperbolic systems; a comparative appraisal of finite difference versus finite element methods; integral and integrodifferential systems; perturbation methods; Monte Carlo methods; finite analytic methods; moving boundary problems; inverse problems; graphical display methods; grid generation methods; and programing methods for supercomputers.

Minkowycz, W.J.; Sparrow, E.M.; Schneider, G.E.; Pletcher, R.H.

1988-01-01T23:59:59.000Z

119

Radiative Heat Transfer between Neighboring Particles  

E-Print Network (OSTI)

The near-field interaction between two neighboring particles is known to produce enhanced radiative heat transfer. We advance in the understanding of this phenomenon by including the full electromagnetic particle response, heat exchange with the environment, and important radiative corrections both in the distance dependence of the fields and in the particle absorption coefficients. We find that crossed terms of electric and magnetic interactions dominate the transfer rate between gold and SiC particles, whereas radiative corrections reduce it by several orders of magnitude even at small separations. Radiation away from the dimer can be strongly suppressed or enhanced at low and high temperatures, respectively. These effects must be taken into account for an accurate description of radiative heat transfer in nanostructured environments.

Alejandro Manjavacas; F. Javier Garcia de Abajo

2012-01-26T23:59:59.000Z

120

Inverse Problems in Heat Transfer  

E-Print Network (OSTI)

This chapter presents a stochastic modeling and statistical inference approach to the solution of inverse problems in thermal transport systems. Of particular interest is the inverse heat conduction problem (IHCP) of estimating an unknown boundary heat flux in a conducting solid given temperature data within the domain. Even though deterministic sequential and whole time domain estimation methods have been applied with success over the years for the solution of such problems, we herein introduce stochastic approaches to representing and solving the IHCP. As most engineering systems and processes operate in an uncertain environment, it becomes increasingly important to address their analysis and inverse design in a stochastic manner using statistical data-driven prior and concurrent information on the system response. Recent advances in spectral stochastic modeling, computational Bayesian and spatial statistics enable complete and e#cient solution procedures to such problems. Two distinct approaches to the IHCP are presented in this chapter one based on spectral stochastic modeling and the other on Bayesian inference. Although these techniques are discussed in the context of the IHCP, the methodologies presented are general and applicable to design and estimation problems in other more complex problems in thermal transport systems including problems in the presence of convection, radiation and conduction. 1

Nicholas Zabaras

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "radiant heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Splice connector with internal heat transfer jacket  

DOE Patents (OSTI)

A heat transfer jacket is placed over the terminal portions of the conductors of a pair of high voltage cables which are connected in a splice connection wherein a housing surrounds the connected conductor portions, the heat transfer jacket extending longitudinally between the confronting ends of a pair of adaptor sleeves placed upon the insulation of the cables to engage and locate the adaptor sleeves relative to one another, and laterally between the conductors and the housing to provide a path of relatively high thermal conductivity between the connected conductor portions and the housing.

Silva, Frank A. (Basking Ridge, NJ); Mayer, Robert W. (Hackettstown, NJ)

1977-01-01T23:59:59.000Z

122

Nanoscale Heat Transfer: from Computation to Experiment  

E-Print Network (OSTI)

Heat transfer can differ distinctly at the nanoscale from that at the macroscale. Recent advancement in computational and experimental techniques has enabled a large number of interesting observations and understanding of heat transfer processes at the nanoscale. In this review, we will first discuss recent advances in computational and experimental methods used in nanoscale thermal transport studies, followed by reviews of novel thermal transport phenomena at the nanoscale observed in both computational and experimental studies, and discussion on current understanding of these novel phenomena. Our perspectives on challenges and opportunities on computational and experimental methods are also presented.

Luo, Tengfei

2013-01-01T23:59:59.000Z

123

Optimization of Phase Change Heat Transfer in Biporous Media  

E-Print Network (OSTI)

transfer analysis of a loop heat pipe with biporous wicks”.Planes”. Frontiers in Heat Pipes Journal 1, 013001 (2010).transfer model of a loop heat pipe with a bidisperse wick

Reilly, Sean

2013-01-01T23:59:59.000Z

124

High intensity discharge lamp self-adjusting ballast system sensitive to the radiant energy or heat of the lamp  

SciTech Connect

This patent describes a self-adjusting ballast system for mercury vapor, high intensity discharge lamps having outputs of 100 watts or greater, comprising: a direct current source; a lamp circuit containing a high intensity discharge lamp; sensing means for sensing the radiant energy output of the lamp; a pulse width modulator which, in response to the output of the sensing means, varies the width of the pulses that power the lamp during warm-up of the lamp; a high frequency oscillator; a DC to AC converter that converts current from the direct source to pulses of alternating current for powering the lamp, the converter comprising: at least one switch for gating current to the lamp; a switch control means, responsive to the high frequency oscillator, for controlling the switch and controlling the frequency of the alternating current pulses that power the lamp; current sensing means for sensing the current being supplied to the lamp; and current control means for limiting the current through the lamp to a predetermined safe level when the current sensed by the current sensing means exceeds a reference value.

Kuhnel, D.S.; Ottenstein, S.A.

1987-07-21T23:59:59.000Z

125

Heat and mass transfer in porous media  

DOE Green Energy (OSTI)

Field test data on the OOSI MR3 experiments are used as a basis for exhibiting the computational capabilities of the WAFE computer code, which is a generalized tool for the analysis of heat and mass transfer in multi-dimensional domains of porous geothermal materials.

Cook, T.L.; Harlow, F.H.; Travis, B.J.; Bartel, T.J.; Tyner, C.E.

1981-01-01T23:59:59.000Z

126

Convective heat transfer in rotating, circular channels  

E-Print Network (OSTI)

Nusselt number values for flow in a rotating reference frame are obtained through computational fluid dynamic (CFD) analysis for Rossby numbers Ro ~1-4 and Reynolds numbers Re ~1,000-2,000. The heat-transfer model is first ...

Hogan, Brenna Elizabeth

2012-01-01T23:59:59.000Z

127

Cooperative heat transfer and ground coupled storage system  

DOE Patents (OSTI)

A cooperative heat transfer and ground coupled storage system wherein collected solar heat energy is ground stored and permitted to radiate into the adjacent ground for storage therein over an extended period of time when such heat energy is seasonally maximally available. Thereafter, when said heat energy is seasonally minimally available and has propagated through the adjacent ground a substantial distance, the stored heat energy may be retrieved by a circumferentially arranged heat transfer means having a high rate of heat transfer.

Metz, Philip D. (Rocky Point, NY)

1982-01-01T23:59:59.000Z

128

heat transfer | OpenEI Community  

Open Energy Info (EERE)

85 85 Varnish cache server Home Groups Community Central Green Button Applications Developer Utility Rate FRED: FRee Energy Database More Public Groups Private Groups Features Groups Blog posts Content Stream Documents Discussions Polls Q & A Events Notices My stuff Energy blogs 429 Throttled (bot load) Error 429 Throttled (bot load) Throttled (bot load) Guru Meditation: XID: 2142229585 Varnish cache server heat transfer Home Dc's picture Submitted by Dc(15) Member 15 November, 2013 - 13:26 Living Walls ancient building system architect biomimicry building technology cooling cu daylight design problem energy use engineer fred andreas geothermal green building heat transfer heating living walls metabolic adjustment net zero pre-electricity Renewable Energy Solar university of colorado utility grid Wind

129

Advanced Heat Transfer and Thermal Storage Fluids  

DOE Green Energy (OSTI)

The design of the next generation solar parabolic trough systems for power production will require the development of new thermal energy storage options with improved economics or operational characteristics. Current heat-transfer fluids such as VP-1?, which consists of a eutectic mixture of biphenyl and diphenyl oxide, allow a maximum operating temperature of ca. 300 C, a limit above which the vapor pressure would become too high and would require pressure-rated tanks. The use of VP-1? also suffers from a freezing point around 13 C that requires heating during cold periods. One of the goals for future trough systems is the use of heat-transfer fluids that can act as thermal storage media and that allow operating temperatures around 425 C combined with lower limits around 0 C. This paper presents an outline of our latest approach toward the development of such thermal storage fluids.

Moens, L.; Blake, D.

2005-01-01T23:59:59.000Z

130

Heat Transfer and Energy Diffusion Analysis of Cannula Ground Heat Exchanger  

Science Conference Proceedings (OSTI)

A heat transfer model about fluid flow and heat conduct in cannula ground heat exchanger were given in this article. The heat transfer characteristics were analyzed by means of numerical method of finite element. Affect of difference size of buried tubes ... Keywords: heat transfer, energy diffusion, ground heat exchanger, numerical method, couple mode

Jiang Yan; Gao Qing; Li Ming

2010-10-01T23:59:59.000Z

131

Heat Transfer between Graphene and Amorphous SiO2  

E-Print Network (OSTI)

We study the heat transfer between graphene and amorphous SiO2. We include both the heat transfer from the area of real contact, and between the surfaces in the non-contact region. We consider the radiative heat transfer associated with the evanescent electromagnetic waves which exist outside of all bodies, and the heat transfer by the gas in the non-contact region. We find that the dominant contribution to the heat transfer result from the area of real contact, and the calculated value of the heat transfer coefficient is in good agreement with the value deduced from experimental data.

B. N. J. Persson; H. Ueba

2010-07-22T23:59:59.000Z

132

Heat Transfer Analysis of Post-Weld Heat Treatment of Grade 91 Steel  

Science Conference Proceedings (OSTI)

The appropriate heat transfer coefficients are determined through the inverse heat conduction method utilizing ceramic heat blankets as well as a furnace as the ...

133

Reversible limit of processes of heat transfer  

E-Print Network (OSTI)

We study a process of heat transfer between a body of heat capacity C(T) and a sequence of N heat reservoirs, with temperatures equally spaced between an initial temperature T_0 and a final temperature T_N. The body and the heat reservoirs are isolated from the rest of the universe, and the body is brought in thermal contact successively with reservoirs of increasing temperature. We determine the change of entropy of the composite thermodynamic system in the total process in which the temperature of the body changes from T_0 to T_N. We find that for large values of N the total change of entropy of the composite process is proportional to (T_N-T_0)/N, but eventually a non-monotonic behavior is found at small values of N.

Stilck, Jürgen F

2013-01-01T23:59:59.000Z

134

SPECIAL HEAT TRANSFER PHENOMENA FOR SUPERCRITICAL FLUIDS  

SciTech Connect

Present-day knowledge concerning the molecular structure of supercritical fluids is briefly reviewed. It is shown that liquid-like and gas- like phases may coexist at supercritical pressures, although they may not be in equllibrium with each other. it is postulated that on the basis of the coexistence of these two phases a "boiling-like" phenomenon may provide the mechanism of heat transfer to supercritical fluids at high heat fluxes and certain other conditions. An unusual mode of heat transfer was actually observed at supercritical pressures during tests which produced the high heat fluxes and other conditions under which such "boiling" would be expected. The tests and the various conditions are briefly described. An emission of high-frequeney, high- intensity sounds usually accompanied these tests. It is shown that similar screaming sounds were heard during boiling at subcritical pressures, giving further support to the hypothesis that "boiling" may occur at supercritical pressures. A seeond possible explanation for the unusual mode of heat transfer is based on boundarylayer stability considerations. At high heat fluxes large density differences exist between the bulk of the fluid and the fluid in the boundary layer near the wall. A breakdown of the boundary layer may be caused by the build-up of ripples between its low-density fluid and the high-density bulk fluid, in a manner quite similar to the breaking of ocean waves at high wind velocities. It is pointed out that the density variation of supercritical fluide may be used to advantage by certrifuging boundary layers. (auth)

Goldmann, K.

1956-01-01T23:59:59.000Z

135

Modelling Heat Transfer in Nanofluids Based on Coupled MD ...  

Science Conference Proceedings (OSTI)

Simulations have shown that the additional heat transfer caused by the collision of the nanoparticles with the heat source contributes significantly to the ...

136

Optimization of Phase Change Heat Transfer in Biporous Media.  

E-Print Network (OSTI)

??As the heat transfer demands placed on small electronics devices increase, the demand for efficient evaporators for heat pipes and spreaders will increase in kind.… (more)

Reilly, Sean

2013-01-01T23:59:59.000Z

137

Thermal radiant exitance model performance: Soils and forests  

DOE Green Energy (OSTI)

Models of surface temperatures of two land surface types based on their energy budgets were developed to simulate the effects of environmental factors on thermal radiant exitance. The performance of these models is examined in detail. One model solves the non-linear differential equation for heat diffusion in solids using a set of submodels for surface energy budget components. The model performance is examined under three desert conditions thought to be a strong test of the submodels. The accuracy of the temperature predictions and submodels is described. The accuracy of the model is generally good but some discrepancies between some of the submodels and measurements are noted. The sensitivity of the submodels is examined and is seen to be strongly controlled by interaction and feedback among energy components that are a function of surface temperature. The second model simulates vegetation canopies with detailed effects of surface geometry on radiant transfer in the canopy. Foliage solar absorption coefficients are calculated using a radiosity approach for a three layer canopy and long wave fluxes are modeled using a view factor matrix. Sensible and latent heat transfer through the canopy are also simulated using, nearby meteorological data but heat storage in the canopy is not included. Simulations for a coniferous forest canopy are presented and the sensitivity of the model to environmental inputs is discussed.

Balick, L.K. [EG& G Energy Measurements Inc., Las Vegas, NV (United States); Smith, J.A. [NASA/Goddard Space Flight Center, Greenbelt, MD (United States). Lab. for Terrestrial Physics

1995-12-31T23:59:59.000Z

138

FEHM (Finite Element Heat and Mass Transfer Code)  

NLE Websites -- All DOE Office Websites (Extended Search)

FEHM (Finite Element Heat and Mass Transfer Code) FEHM (Finite Element Heat and Mass Transfer Code) FEHM is used to simulate groundwater and contaminant flow and transport in deep...

139

Nanofluid heat transfer enhancement for nuclear reactor applications  

E-Print Network (OSTI)

Colloidal dispersions of nanoparticles are known as `nanofluids'. Such engineered fluids offer the potential for enhancing heat transfer, particularly boiling heat transfer, while avoiding the drawbacks (i.e., erosion, ...

Buongiorno, Jacopo

140

Heat Transfer in Projecting and Sloped Fenestration Products  

NLE Websites -- All DOE Office Websites (Extended Search)

Heat Transfer in Projecting and Sloped Fenestration Products Speaker(s): Dragan Charlie Curcija Date: May 26, 2010 - 12:00pm Location: 90-3122 The heat transfer performance of...

Note: This page contains sample records for the topic "radiant heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Heat transfer during film condensation of potassium vapor  

E-Print Network (OSTI)

The object of this work is to investigate theoretically and experimentally the following two phases of heat transfer during condensation of potassium vapore, a. Heat transfer during film condensation of pure saturated ...

Kroger, Detlev Gustav

1966-01-01T23:59:59.000Z

142

Identification of Convection Heat Transfer Coefficient of Secondary Cooling Zone of CCM based on Least Squares Method and Stochastic Approximation Method  

E-Print Network (OSTI)

The detailed mathematical model of heat and mass transfer of steel ingot of curvilinear continuous casting machine is proposed. The process of heat and mass transfer is described by nonlinear partial differential equations of parabolic type. Position of phase boundary is determined by Stefan conditions. The temperature of cooling water in mould channel is described by a special balance equation. Boundary conditions of secondary cooling zone include radiant and convective components of heat exchange and account for the complex mechanism of heat-conducting due to airmist cooling using compressed air and water. Convective heat-transfer coefficient of secondary cooling zone is unknown and considered as distributed parameter. To solve this problem the algorithm of initial adjustment of parameter and the algorithm of operative adjustment are developed.

Ivanova, Anna

2010-01-01T23:59:59.000Z

143

An experimental study of the flow and heat transfer between enhanced heat transfer plates for PHEs  

Science Conference Proceedings (OSTI)

The flow and heat transfer between inclined discrete rib plates for plate heat exchangers have been experimentally studied. Dye injection method is used to visualize the flow structures. The visualization results show that front vortex, rear vortex and main vortex are formed between the plates. The rib parameter influence is also studied using visualization method. The pressure drop and heat transfer between the inclined discrete rib plates as well as that between inclined continuous rib plates and smooth plates are also measured. The measured results show that the inclined discrete rib plate can enhanced heat transfer 20-25% at the same pumping power compared with the commonly used inclined continuous rib plates. (author)

Li, Xiao-wei [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Meng, Ji-an; Li, Zhi-xin [School of Aerospace, Tsinghua University, Beijing 100084 (China)

2010-11-15T23:59:59.000Z

144

Heat Transfer Operators Associated with Quantum Operations  

E-Print Network (OSTI)

Any quantum operation applied on a physical system is performed as a unitary transformation on a larger extended system. If the extension used is a heat bath in thermal equilibrium, the concomitant change in the state of the bath necessarily implies a heat exchange with it. The dependence of the average heat transferred to the bath on the initial state of the system can then be found from the expectation value of a hermitian operator, which is named as the heat transfer operator (HTO). The purpose of this article is the investigation of the relation between the HTOs and the associated quantum operations. Since, any given quantum operation on a system can be realized by different baths and unitaries, many different HTOs are possible for each quantum operation. On the other hand, there are also strong restrictions on the HTOs which arise from the unitarity of the transformations. The most important of these is the Landauer erasure principle. This article is concerned with the question of finding a complete set of restrictions on the HTOs that are associated with a given quantum operation. An answer to this question has been found only for a subset of quantum operations. For erasure operations, these characterizations are equivalent to the generalized Landauer erasure principle. For the case of generic quantum operations however, it appears that the HTOs obey further restrictions which cannot be obtained from the entropic restrictions of the generalized Landauer erasure principle.

Ç. Aksak; S. Turgut

2010-02-03T23:59:59.000Z

145

NISTIR 6299 A Heat Transfer Model for Fire Fighter's ...  

Science Conference Proceedings (OSTI)

Page 1. NISTIR 6299 A Heat Transfer Model for Fire Fighter's Protective Clothing William E. Mell J. Randall Lawson United ...

1999-05-06T23:59:59.000Z

146

Heat Transfer Fluids Containing Nanoparticles (08-066)  

The issue of heat transfer offers fertile ground for scientific exploration across many disciplines. Argonne researchers have discovered the potential ...

147

Handbook of heat transfer fundamentals (2nd edition)  

SciTech Connect

Recent advances in heat transfer are discussed, providing data and methodology to solve a wide range of heat transfer problems. The topics considered include: basic concepts of heat transfer, mathematical methods, thermophysical properties, conduction, numerical methods in heat transfer, natural convection, and internal duct flow and external flows in forced convection. Also addressed are: rarefied gases, electric and magnetic fields, condensation, boiling, two-phase flow, and radiation.

Rohsenow, W.M.; Hartnett, J.P.; Ganic, E.N.

1985-01-01T23:59:59.000Z

148

Handbook of heat and mass transfer. Volumes 1 and 2  

Science Conference Proceedings (OSTI)

This two-volume series presents advanced topics in industrial heat and mass transfer operations for reactor design technology.

Cheremisinoff, N.P.

1985-01-01T23:59:59.000Z

149

Molten Salt Heat Transfer Fluid (HTF) - Energy Innovation Portal  

Solar Thermal Industrial Technologies Energy Storage Molten Salt Heat Transfer Fluid (HTF) Sandia National Laboratories. Contact SNL About This ...

150

Heat Transfer Characteristics of Magnetite under Microwave Irradiation  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, 2012 TMS Annual Meeting & Exhibition. Symposium , Materials Processing Fundamentals. Presentation Title, Heat Transfer ...

151

Heat transfer of finned tube bundles in crossflow  

SciTech Connect

This volume correlates findings on heat transfer and hydraulic drag of bundles of finned tubes in crossflow at Reynolds numbers from 10/sup 4/ to 10/sup 6/. These studies illustrate fin, local, and mean heat transfer coefficients; effects of geometric parameters of the fins; effect of tube location within the bundle on heat transfer and hydraulic drag; and resistance of finned tube bundles.

Stasiulevicius, J.; Skrinska, A.; Zukauskas, A.

1988-01-01T23:59:59.000Z

152

Exploring the Limits of Boiling and Evaporative Heat Transfer Using Micro/Nano Structures  

E-Print Network (OSTI)

Comparison of various heat transfer coefficient models inpool boiling In summary, high heat transfer coefficientin boiling heat transfer can be generally explained by the

Lu, Ming-Chang

2010-01-01T23:59:59.000Z

153

DEVELOPING FLOW AND HEAT TRANSFER IN STRONGLY CURVED DUCTS OF RECTANGULAR CROSS-SECTION  

E-Print Network (OSTI)

Forced Convection Heat Transfer in Curved RectangularInfluence of Curvature on Heat Transfer to IncompressibleT. , "Forced Convective Heat Transfer in a Curved Channel

Yee, G.

2010-01-01T23:59:59.000Z

154

Heat Transfer Limitations in Hydrogen Production Via Steam Reformation: The Effect of Reactor Geometry  

E-Print Network (OSTI)

Ohsawa, Katsuyuki, “Heat Transfer Enhancement in Methanolsin the Catalyst Bed”, Heat Transfer-Asian Research, Vol.CA FUELCELL2006-97109 HEAT TRANSFER LIMITATIONS IN HYDROGEN

Vernon, David R.; Davieau, David D.; Dudgeon, Bryce A.; Erickson, Paul A.

2006-01-01T23:59:59.000Z

155

Exploring the Limits of Boiling and Evaporative Heat Transfer Using Micro/Nano Structures  

E-Print Network (OSTI)

and condensation processes in heat transfer equipment, 2ndand condensation processes in heat transfer equipment, in,the convection process, the heat transfer coefficient of

Lu, Ming-Chang

2010-01-01T23:59:59.000Z

156

Experimental Study of the Floor Radiant Cooling System Combined with Displacement Ventilation  

E-Print Network (OSTI)

As a comfortable and energy-efficient air conditioning system, the application of floor radiant heating system is used increasingly greatly in the north of China. As a result, the feasibility of floor radiant cooling has gained more attention. To examine the thermodynamic performance of the floor radiant cooling system, we measured the operational conditions including the minimum floor surface temperature, the cooling capacity, and the indoor temperature field distribution under different outdoor temperatures in Beijing. Because the ground temperature changes with the mean temperature of the supplied and returned water and room temperature, the mean temperature of the supplied and retuned water was obtained. Finally, we analyzed the phenomenon of dewing and developed measures for preventing it. The dry air layer near the floor formed by a displacement ventilation system can effectively prevent dews on the surface of the floor in the wet and hot days in summer. In addition, for the sake of the displacement ventilation system, the heat transfer effect between floor and space is enhanced. Our analysis pointed out that floor radiant cooling system combined with displacement ventilation ensures good comfort and energy efficiency.

Ren, Y.; Li, D.; Zhang, Y.

2006-01-01T23:59:59.000Z

157

Air-To-Water Heat Pumps with Radiant Delivery in Low Load Homes: Tucson, Arizona and Chico, California (Fact Sheet)  

SciTech Connect

Space conditioning represents nearly 50% of average residential household energy consumption, highlighting the need to identify alternative cost-effective, energy-efficient cooling and heating strategies. As homes are better built, there is an increasing need for strategies that are particularly well suited for high performance, low load homes. ARBI researchers worked with two test homes in hot-dry climates to evaluate the in-situ performance of air-to-water heat pump (AWHP) systems, an energy efficient space conditioning solution designed to cost-effectively provide comfort in homes with efficient, safe, and durable operation. Two monitoring projects of test houses in hot-dry climates were initiated in 2010 to test this system. Both systems were fully instrumented and have been monitored over one year to capture complete performance data over the cooling and heating seasons. Results are used to quantify energy savings, cost-effectiveness, and system performance using different operating modes and strategies. A calibrated TRNSYS model was developed and used to evaluate performance in various climate regions. This strategy is most effective in tight, insulated homes with high levels of thermal mass (i.e. exposed slab floors).

Not Available

2013-11-01T23:59:59.000Z

158

Heat Transfer Fluids for Solar Water Heating Systems | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Heat Transfer Fluids for Solar Water Heating Systems Heat Transfer Fluids for Solar Water Heating Systems Heat Transfer Fluids for Solar Water Heating Systems May 16, 2013 - 3:02pm Addthis Illustration of a solar water heater. Illustration of a solar water heater. Heat-transfer fluids carry heat through solar collectors and a heat exchanger to the heat storage tanks in solar water heating systems. When selecting a heat-transfer fluid, you and your solar heating contractor should consider the following criteria: Coefficient of expansion - the fractional change in length (or sometimes in volume, when specified) of a material for a unit change in temperature Viscosity - resistance of a liquid to sheer forces (and hence to flow) Thermal capacity - the ability of matter to store heat Freezing point - the temperature below which a liquid turns into a

159

Effects of winglets to augment tube wall heat transfer in louvered fin heat exchangers  

E-Print Network (OSTI)

Effects of winglets to augment tube wall heat transfer in louvered fin heat exchangers Paul A Abstract The louvered fin heat exchanger, a type of compact heat exchanger, has been used heavily transfer along the tube wall of the compact heat exchanger through the use of winglets placed

Thole, Karen A.

160

CORRELATING EVAPORATION HEAT TRANSFER COEFFICIENT OF REFRIGERANT R-134a IN A PLATE HEAT EXCHANGER  

E-Print Network (OSTI)

1 CORRELATING EVAPORATION HEAT TRANSFER COEFFICIENT OF REFRIGERANT R-134a IN A PLATE HEAT EXCHANGER for evaporation heat transfer coefficient of refrigerant R-134a flowing in a plate heat exchanger. Correlation heat exchanger are found to result in large discrepancies with their own experimental data

Kandlikar, Satish

Note: This page contains sample records for the topic "radiant heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Characteristics of multimode heat transfer in a differentially-heated horizontal rectangular duct.  

E-Print Network (OSTI)

??This study presents the numerical analysis of steady laminar flow heat transfer in a horizontal rectangular duct with differential heating on the vertical walls. Three… (more)

Wangdhamkoom, Panitan

2007-01-01T23:59:59.000Z

162

Factors affecting oscillating motion and heat transfer in an oscillating heat pipe .  

E-Print Network (OSTI)

??As demand has grown for thermal management solutions, interest in passive heat transfer devices such as heat pipes has grown as well. In particular, oscillating… (more)

Smoot, Christopher

2013-01-01T23:59:59.000Z

163

Heat transfer assembly for a fluorescent lamp and fixture  

DOE Patents (OSTI)

In a lighting fixture including a lamp and a housing, a heat transfer structure is disclosed for reducing the minimum lamp wall temperature of a fluorescent light bulb. The heat transfer structure, constructed of thermally conductive material, extends from inside the housing to outside the housing, transferring heat energy generated from a fluorescent light bulb to outside the housing where the heat energy is dissipated to the ambient air outside the housing. Also disclosed is a method for reducing minimum lamp wall temperatures. Further disclosed is an improved lighting fixture including a lamp, a housing and the aforementioned heat transfer structure. 11 figs.

Siminovitch, M.J.; Rubenstein, F.M.; Whitman, R.E.

1992-12-29T23:59:59.000Z

164

Heat transfer assembly for a fluorescent lamp and fixture  

DOE Patents (OSTI)

In a lighting fixture including a lamp and a housing, a heat transfer structure is disclosed for reducing the minimum lamp wall temperature of a fluorescent light bulb. The heat transfer structure, constructed of thermally conductive material, extends from inside the housing to outside the housing, transferring heat energy generated from a fluorescent light bulb to outside the housing where the heat energy is dissipated to the ambient air outside the housing. Also disclosed is a method for reducing minimum lamp wall temperatures. Further disclosed is an improved lighting fixture including a lamp, a housing and the aforementioned heat transfer structure.

Siminovitch, Michael J. (Richmond, CA); Rubenstein, Francis M. (Berkeley, CA); Whitman, Richard E. (Richmond, CA)

1992-01-01T23:59:59.000Z

165

Heat transfer to impacting drops and post critical heat flux dispersed flow  

E-Print Network (OSTI)

Heat transfer to drops impacting on a hot surface is examined in context of dispersions of flowing, boiling fluids. The liquid contribution to heat transfer from a hot tube to a two-phase dispersion is formulated in terms ...

Kendall, Gail E.

1978-01-01T23:59:59.000Z

166

HEAT TRANSFER AND TRITIUM PRODUCING SYSTEM  

DOE Patents (OSTI)

This invention related to a circulating lithium-containing blanket system in a neution source hav'ing a magnetic field associated therewith. The blanket serves simultaneously and efficiently as a heat transfer mediunm and as a source of tritium. The blanket is composed of a lithium-6-enriched fused salt selected from the group consisting of lithium nitrite, lithium nitrate, a mixture of said salts, a mixture of each of said salts with lithium oxide, and a mixture of said salts with each other and with lithium oxide. The moderator, which is contained within the blanket in a separate conduit, can be water. A stellarator is one of the neutron sources which can be used in this invention. (AEC)

Johnson, E.F.

1962-06-01T23:59:59.000Z

167

Heat transfer in bundles of finned tubes in crossflow  

SciTech Connect

This book provides correlations of heat transfer and hydraulic data for bundles of finned tubes in crossflow at high Reynolds numbers. Results of studies of the effectiveness of the fin, local, and mean heat transfer coefficients are presented. The effect of geometric parameters of the fins and of the location of tubes in the bundle on heat transfer and hydraulic drag are described. The resistance of the finned tube bundles under study and other factors are examined.

Stasiulevicius, J.; Skrinska, A.; Zukauskas, A.; Hewitt, G.F.

1986-01-01T23:59:59.000Z

168

ETTM - Heat Transfer Calculations Version 1.0  

Science Conference Proceedings (OSTI)

ETTM Heat Transfer Calculations is a computer based training module that allows users to access training when desired and review it at their own pace. It provides graphics and limited interactive features to enhance learning. This module reviews the basic engineering principles used to calculate heat transfer and how to apply these principles to typical nuclear plant applications. The calculation of heat transfer in plant systems is an important element of many engineering calculations. Students should r...

2010-09-27T23:59:59.000Z

169

Heat transfer in freeboard region of fluidized beds  

SciTech Connect

This research involved the study of heat transfer and fluid mechanic characteristics around a horizontal tube in the freeboard region of fluidized beds. Heat transfer coefficients were experimetnally measured for different bed temperatures, particle sizes, gas flow rates, and tube elevations in the freeboard region of air fluidized beds at atmospheric pressure. Local heat transfer coefficients were found to vary significantly with angular position around the tube. Average heat transfer coefficients were found to decrease with increasing freeboard tube elevation and approach the values for gas convection plus radiation for any given gas velocity. For a fixed tube elevation, heat transfer coefficients generally increased with increasing gas velocity and with high particle entrainment they can approach the magnitudes found for immersed tubes. Heat transfer coefficients were also found to increase with increasing bed temperature. It was concluded that this increase is partly due to increase of radiative heat transfer and partly due to change of thermal properties of the fluidizing gas and particles. To investigate the fluid mechanic behavior of gas and particles around a freeboard tube, transient particle tube contacts were measured with a special capacitance probe in room temperature experiments. The results indicated that the tube surface experiences alternating dense and lean phase contacts. Quantitative information for local characteristics was obtained from the capacitance signals and used to develop a phenomenological model for prediction of the heat transfer coefficients around freeboard tubes. The packet renewal theory was modified to account for the dense phase heat transfer and a new model was suggested for the lean phase heat transfer. Finally, an empirical freeboard heat transfer correlation was developed from functional analysis of the freeboard heat transfer data using nondimensional groups representing gas velocity and tube elevation.

Biyikli, S.; Tuzla, K.; Chen, J.C.

1983-10-01T23:59:59.000Z

170

HEAT TRANSFER IN UNDERGROUND HEATING EXPERIMENTS IN GRANITE, STRIPA, SWEDEN  

E-Print Network (OSTI)

CLOSED-FORM INTEGRAL SOLUTIONS FOR LINEAR HEAT CONDUCTION.For linear heat conduction in a homogeneous, isotropiclaw of similitude for linear heat conduction was utilized to

Chan, T.

2010-01-01T23:59:59.000Z

171

Comparison of Zone Cooling Load for Radiant and All-Air Conditioning Systems  

E-Print Network (OSTI)

Load for Radiant and Air Conditioning Systems. ProceedingsRefrigerating and Air Conditioning Engineers Inc. Babiak,of European Heating ahd Air-Conditioning Associations. CEN (

Feng, Jingjuan; Schiavon, Stefano; Bauman, Fred

2012-01-01T23:59:59.000Z

172

Study on the Interfacial Heat Transfer Coefficient of High Pressure ...  

Science Conference Proceedings (OSTI)

The heat transfer behavior between an AM60B alloy casting and die during .... for Spent Nuclear Fuel and Measuring the Composition of Molten Salt by Using ...

173

Thermal Storage and Advanced Heat Transfer Fluids (Fact Sheet...  

NLE Websites -- All DOE Office Websites (Extended Search)

Thermophysical Properties In our Thermal Storage Materials Laboratory, we use a variety of instruments to measure the thermophysical properties of heat transfer fluids and storage...

174

Characterization and Development of Advanced Heat Transfer Technologies (Presentation)  

DOE Green Energy (OSTI)

This presentation gives an overview of the status and FY09 accomplishments for the NREL thermal management research project 'Characterization and Development of Advanced Heat Transfer Technologies'.

Kelly, K.

2009-05-01T23:59:59.000Z

175

Estimation of Heat Transfer Coefficient in Squeeze Casting of ...  

Science Conference Proceedings (OSTI)

The casting-die interfacial heat transfer coefficient(IHTC) in 5-step casting was .... from First-Principles: Solid-Solution Strengthening, Softening, and Cross-Slip.

176

Handbook of thermodynamics, heat transfer and fluid flow  

E-Print Network (OSTI)

9 Nov 2010 ... Handbook of thermodynamics, heat transfer and fluid flow | JUNE 1992 | 3 Volume | U.S. Department of Energy FSC-6910 Washington, D.C. ...

177

A versatile procedure for calculating heat transfer through windows  

SciTech Connect

Advances in window technologies and the desire to standardize the reporting of standard window heat transfer indices have necessitated the development of a comprehensive analytical procedure for calculating heat transfer through windows. This paper shows how complete window heat transfer can be considered as the area-weighted sum of the three window component areas: the center-of-glass area, the edge-of-glass area, and the frame area. Algorithms for calculating heat transfer through each of these areas and for combining these to calculate total window indices are presented. 36 refs., 5 figs., 6 tabs.

Arasteh, D.K.; Reilly, M.S.; Rubin, M.D.

1989-05-01T23:59:59.000Z

178

Impact of Heat Transfer Media on Materials for Concentrated Solar ...  

Science Conference Proceedings (OSTI)

Presentation Title, Impact of Heat Transfer Media on Materials for Concentrated Solar Power. Author(s), Dane Wilson. On-Site Speaker (Planned), Dane Wilson.

179

Applications of COMSOL Multiphysics Software to Heat Transfer Processes.  

E-Print Network (OSTI)

??This thesis used the study of Heat Transfer and COMSOL Multiphysics software as a reference which was made for the purpose of future education in… (more)

Xiong, Wei

2010-01-01T23:59:59.000Z

180

Microcellular Biomorphous Ceramics for Two Phase Heat Transfer ...  

Science Conference Proceedings (OSTI)

Heat transfer behavior of microcellular biomorphous Al2O3 was evaluated by a fluid-dynamic approach and tested in a planar capillary evaporator.

Note: This page contains sample records for the topic "radiant heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

NREL Improves Window Heat Transfer Calculations (Fact Sheet)...  

NLE Websites -- All DOE Office Websites (Extended Search)

and interior radiation. The most significant errors were found in detailed window heat transfer algorithms due to implementation problems. The results show a decrease in...

182

Heat Transfer through Materials: Application to Silica Aerogels...  

NLE Websites -- All DOE Office Websites (Extended Search)

Heat Transfer through Materials: Application to Silica Aerogels and Building Envelopes Speaker(s): Brangre Lartigue Date: December 19, 2005 - 12:00pm Location: Bldg. 90 After...

183

Phase Change Materials for Enhancing Heat Transfer in Thermal ...  

Science Conference Proceedings (OSTI)

One of the main issues with using phase change materials is that solidification often reduces total heat transfer, reducing the efficiency of the storage system.

184

Rotating Heat Transfer in High Aspect Ratio Rectangular Cooling...  

NLE Websites -- All DOE Office Websites (Extended Search)

Reynolds Number (Nu Nu o ) (f f o ) 24% Increase in Cooling Performance Rotating Heat Transfer in High Aspect Ratio Rectangular Cooling Passages with Shaped Turbulators...

185

CFD Modelling of Heat Transfer in Supersonic Nozzles for ... - TMS  

Science Conference Proceedings (OSTI)

May 1, 2007 ... CFD Modelling of Heat Transfer in Supersonic Nozzles for Magnesium Production by Peter Witt, M.N.H. Khan, and Geoffrey Brooks ...

186

Enhanced boiling heat transfer by submerged, vibration induced jets .  

E-Print Network (OSTI)

??In this analysis, the efficacy of cavitation jets for heat transfer enhancement was demonstrated. The cavitation jet was formed from a cluster of cavitation bubbles… (more)

Tillery, Steven W.

2005-01-01T23:59:59.000Z

187

Evaluation of Transient Heat Transfer Coefficient Evolution in ...  

Science Conference Proceedings (OSTI)

As known, physical and geometrical aspects play a fundamental role on the heat transfer conditions during the solidification process. This high dependence of ...

188

Determination of Heat Transfer Coefficient Distribution at Part ...  

Science Conference Proceedings (OSTI)

... of oil flow on the heat transfer coefficient (HTC) distribution at the gear surface. ... Multiphase Flow in a Steelmaking Converter Using an Unconventional Lance.

189

Comparison of heat transfer in solar collectors with heat pipe versus flow through absorbers  

DOE Green Energy (OSTI)

Analysis of heat transfer in solar collectors with heat pipe absorbers is compared to that for collectors with flow through absorbers. Both pumped and thermosiphon systems that produce hot water or other heated fluids are discussed. In these applications the heat pipe absorber suffers a heat transfer penalty compared with the flow through absorber, but in many cases the penalty can be minimized by proper design at the heat pipe condenser and system manifold. When the solar collector is used to drive an absorption chiller, the heat pipe absorber has better heat transfer characteristics than the flow through absorber.

Hull, J.R.

1985-01-01T23:59:59.000Z

190

2.51 Intermediate Heat and Mass Transfer, Fall 2001  

E-Print Network (OSTI)

Analysis, modeling, and design of heat and mass transfer processes with application to common technologies. Unsteady heat conduction in one or more dimensions, steady conduction in multidimensional configurations, numerical ...

Lienhard, John H., 1961-

191

Heat transfer and pressure drop in tape generated swirl flow  

E-Print Network (OSTI)

The heat transfer and pressure drop characteristics of water in tape generated swirl flow were investigated. The test sections were electrically heated small diameter nickel tubes with tight fitting full length Inconel ...

Lopina, Robert F.

1967-01-01T23:59:59.000Z

192

Heat transfer and condensation of water vapour from humid air in compact heat exchangers.  

E-Print Network (OSTI)

??In this thesis, an experimental and simulation study of heat transfer in water-to-air compact-plate heat exchanger is presented. A compact-plate heat exchanger made of polypropylene,… (more)

Saraireh, Mohammad

2012-01-01T23:59:59.000Z

193

HEAT TRANSFER IN UNDERGROUND HEATING EXPERIMENTS IN GRANITE, STRIPA, SWEDEN  

E-Print Network (OSTI)

law of similitude for linear heat conduction was utilized tothe analogy between heat conduction and fluid flow in por­the effects of heat conduction through the vermiculite heat

Chan, T.

2010-01-01T23:59:59.000Z

194

Gas heat transfer in a heated vertical channel under deteriorated turbulent heat transfer regime  

E-Print Network (OSTI)

Passive cooling via natural circulation of gas after a loss of coolant (LOCA) accident is one of the major goals of the Gas-cooled Fast Reactor (GFR). Due to its high surface heat flux and low coolant velocities under ...

Lee, Jeongik

2007-01-01T23:59:59.000Z

195

Gas Heat Transfer in a Heated Vertical Channel under Deteriorated Turbulent Heat Transfer Regime  

E-Print Network (OSTI)

Passive cooling via natural circulation of gas after a loss of coolant (LOCA) accident is one of the major goals of the Gas-cooled Fast Reactor (GFR). Due to its high surface heat flux and low coolant velocities under ...

Lee, Jeongik

196

Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump  

DOE Patents (OSTI)

Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium. A combination of weak and rich liquor working solution is used as the heat transfer medium.

Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI)

1996-12-03T23:59:59.000Z

197

Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump  

DOE Patents (OSTI)

Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium.

Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI); Marsala, Joseph (Glen Ellyn, IL)

1994-11-29T23:59:59.000Z

198

Developing Low-Conductance Window Frames: Capabilities and Limitations of Current Window Heat Transfer Design Tools  

E-Print Network (OSTI)

860. Batchelor, G.K. 1954. Heat transfer by free convectionfree convection. In: Heat Transfer and Turbulent BuoyantHEAT2, A PC-program for heat transfer in two dimensions.

Gustavsen, Arild

2009-01-01T23:59:59.000Z

199

Heat and moisture transfer through clothing  

E-Print Network (OSTI)

capacitance of clothing. Heat capacity of the clothing hasSuffix a cl c e m n r s area (m²) specific heat capacity (J/kgK) heat capacity (J/K) clothing surface area factor view

Voelker, Conrad; Hoffmann, Sabine; Kornadt, Oliver; Arens, Edward; Zhang, Hui; Huizenga, Charlie

2009-01-01T23:59:59.000Z

200

Engineering Fundamentals - Heat Transfer & Fluid Flow, Version 6.0  

Science Conference Proceedings (OSTI)

The Heat Transfer and Fluid Flow module covers basic terms and concepts of heat transfer and fluid flow and discusses their applications in nuclear power plants. This course will help new engineers understand how their work might impact and/or be ...

2013-01-17T23:59:59.000Z

Note: This page contains sample records for the topic "radiant heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Enhanced radiative heat transfer between nanostructured gold plates  

E-Print Network (OSTI)

We compute the radiative heat transfer between nanostructured gold plates in the framework of the scattering theory. We predict an enhancement of the heat transfer as we increase the depth of the corrugations while keeping the distance of closest approach fixed. We interpret this effect in terms of the evolution of plasmonic and guided modes as a function of the grating's geometry.

R. Guérout; J. Lussange; F. S. S. Rosa; J. -P. Hugonin; D. A. R. Dalvit; J. -J. Greffet; A. Lambrecht; S. Reynaud

2012-03-07T23:59:59.000Z

202

Vaporization, dispersion, and radiant fluxes from LPG spills. Final technical report  

SciTech Connect

Both burning and non-burning spills of LPG (primarily propane) were studied. Vaporization rates for propane spills on soil, concrete, insulating concrete, asphalt, sod, wood, and polymer foams were measured. Thermal conductivity, heat transfer coefficients, and steady state vaporization rates were determined. Vapor concentrations were measured downwind of open propane pools and a Gaussian dispersion model modified for area sources provided a good correlation of measured concentrations. Emitted and incident radiant fluxes from propane fires were measured. Simplified flame radiation models were adequate for predicting radiant fluxes. Tests in which propane was sprayed into the air showed that at moderately high spray rates all the propane flashed to vapor or atomized; no liquid collected on the ground.

1982-05-01T23:59:59.000Z

203

Dual circuit embossed sheet heat transfer panel  

DOE Patents (OSTI)

A heat transfer panel provides redundant cooling for fusion reactors or the like environment requiring low-mass construction. Redundant cooling is provided by two independent cooling circuits, each circuit consisting of a series of channels joined to inlet and outlet headers. The panel comprises a welded joinder of two full-size and two much smaller partial-size sheets. The first full-size sheet is embossed to form first portions of channels for the first and second circuits, as well as a header for the first circuit. The second full-sized sheet is then laid over and welded to the first full-size sheet. The first and second partial-size sheets are then overlaid on separate portions of the second full-sized sheet, and are welded thereto. The first and second partial-sized sheets are embossed to form inlet and outlet headers, which communicate with channels of the second circuit through apertures formed in the second full-sized sheet. 6 figs.

Morgan, G.D.

1984-02-21T23:59:59.000Z

204

Dual circuit embossed sheet heat transfer panel  

DOE Patents (OSTI)

A heat transfer panel provides redundant cooling for fusion reactors or the like environment requiring low-mass construction. Redundant cooling is provided by two independent cooling circuits, each circuit consisting of a series of channels joined to inlet and outlet headers. The panel comprises a welded joinder of two full-size and two much smaller partial-size sheets. The first full-size sheet is embossed to form first portions of channels for the first and second circuits, as well as a header for the first circuit. The second full-sized sheet is then laid over and welded to the first full-size sheet. The first and second partial-size sheets are then overlaid on separate portions of the second full-sized sheet, and are welded thereto. The first and second partial-sized sheets are embossed to form inlet and outlet headers, which communicate with channels of the second circuit through apertures formed in the second full-sized sheet.

Morgan, Grover D. (St. Louis County, MO)

1984-01-01T23:59:59.000Z

205

The heat transfer mechanism in aqueous foam flow in a channel  

Science Conference Proceedings (OSTI)

The Heat transfer mechanism in two-phase aqueous foam flow was investigated for developing energy-efficient heat exchangers. Such heat exchangers can provide low consumption of energy resources due to enhanced heat transfer rates. An enhanced heat transfer ... Keywords: aqueous foam flow, heat exchangers, heat transfer

Irena Gabrielaitien?; Jonas Gylys; Rolandas Jonynas; Tadas Ždankus

2011-12-01T23:59:59.000Z

206

Heat transfer between elastic solids with randomly rough surfaces  

E-Print Network (OSTI)

We study the heat transfer between elastic solids with randomly rough surfaces. We include both the heat transfer from the area of real contact, and the heat transfer between the surfaces in the noncontact regions. We apply a recently developed contact mechanics theory, which accounts for the hierarchical nature of the contact between solids with roughness on many different length scales. For elastic contact, at the highest (atomic) resolution the area of real contact typically consists of atomic (nanometer) sized regions, and we discuss the implications of this for the heat transfer. For solids with very smooth surfaces, as is typical in many modern engineering applications, the interfacial separation in the non-contact regions will be very small, and for this case we show the importance of the radiative heat transfer associated with the evanescent electromagnetic waves which exist outside of all bodies.

B. N. J. Persson; B. Lorenz; A. I. Volokitin

2009-08-27T23:59:59.000Z

207

Heat Transfer Fluids for Solar Water Heating Systems | Department...  

NLE Websites -- All DOE Office Websites (Extended Search)

exchanger. | Photo from iStockphoto.com Heat Exchangers for Solar Water Heating Systems Rooftop solar water heaters need regular maintenance to operate at peak efficiency. |...

208

Modeling of Residential Attics with Radiant Barriers  

E-Print Network (OSTI)

This paper gives a summary of the efforts at ORNL in modeling residential attics with radiant barriers. Analytical models based on a system of macroscopic heat balances have been developed. Separate models have been developed for horizontal radiant barriers laid on top of the insulation, and for radiant barriers attached to the bottom of the top chords of the attic trusses. The models include features such as a radiation interchange analysis within the attic space, convective coupling with the ventilation air, and sorption/desorption of moisture at surfaces facing the attic enclosure. The paper gives details of the models and the engineering assumptions that were made in their development. The paper also reports on the status of efforts that are underway to verify the models by comparing their predictions with the results of laboratory and field tests on residential attics and test cells, both with and without radiant barriers. Comparisons are given for a number of selected sets of experimental data. Suggestions are given for needed model refinements and additional experimental data. Plans for utilization of the models for extrapolation to seasonal and annual performance in a variety of climatic conditions are also described.

Wilkes, K. E.

1988-01-01T23:59:59.000Z

209

Liquid Crystal Technique Application for Heat Transfer Investigation in a Fin-Tube Heat Exchanger Element  

Science Conference Proceedings (OSTI)

The use of thermochromic liquid crystal technique (LCT) and true-colour image processing system in heat transfer modelling is described. Experimental procedure, led on rig at Technical University of Gdansk, cover full-field flow patterns in heat exchanger ... Keywords: heat transfer, thermochromic liquid crystals, vortex generator, wind tunnel

M. Wierzbowski; J. Stasiek

2002-04-01T23:59:59.000Z

210

Improved Heat Transfer and Performance of High Intensity Combustion Systems for Reformer Furnace Applications  

E-Print Network (OSTI)

Developments over the past fifteen years have evolved new short flame, high intensity (1,000,000 BTU/HR/ft3 ) combustion systems for industrial uses. Such systems produce a more uniform and higher heat flux than conventional low intensity systems and should enable substantial capital cost savings in new furnace applications. Recent performance improvements established from tests of high intensity combustion systems are described along with advances made in the analytical prediction of design performance. High intensity combustion systems can operate at zero excess air conditions without generating undesirable constituents in the exhaust. A more uniform gas temperature and gas emissivity renders modeling and design of the furnace radiant heat transfer section more realistic. 'Over-design' to allow for the less determinate conditions typical of low intensity, turbulent diffusion oil flame systems should be avoidable. A model has been set up and results generated which indicate the potentialities of the above premise. The application of vortex stabilized high intensity burners for reformer furnaces in the petrochemical industry is then reviewed and emphasized.

Williams, F. D. M.; Kondratas, H. M.

1983-01-01T23:59:59.000Z

211

Error Analysis of Heat Transfer for Finned-Tube Heat-Exchanger Text-Board  

E-Print Network (OSTI)

In order to reduce the measurement error of heat transfer in water and air side for finned-tube heat-exchanger as little as possible, and design a heat-exchanger test-board measurement system economically, based on the principle of test-board system error analyses and design, the equation of measurement error of heat transfer in air side and water side about orifice meter for the finned-tube heat-exchanger was obtained. This paper studies the major factors that may influence the largest admitted measurement error of measurement instruments for heat transfer in water and air side, and analyzes the degree that water temperature and pressure measurement influence heat transfer in water side, and the degree that wet bulb temperature difference measurement influences heat transfer in air side. Finally, this paper indicates that the key problem of reducing heat transfer in water side is water temperature measurement of the in-out pipe of heat-exchanger, and wet bulb temperature difference is a key to decrease the heat transfer in air side for finned-tube heat-exchanger. This paper gives a theoretical instruction for designing the measurement system of a finned-tube heat-exchanger test-board

Chen, Y.; Zhang, J.

2006-01-01T23:59:59.000Z

212

Enhanced two phase flow in heat transfer systems  

DOE Patents (OSTI)

A family of structures and designs for use in devices such as heat exchangers so as to allow for enhanced performance in heat exchangers smaller and lighter weight than other existing devices. These structures provide flow paths for liquid and vapor and are generally open. In some embodiments of the invention, these structures can also provide secondary heat transfer as well. In an evaporate heat exchanger, the inclusion of these structures and devices enhance the heat transfer coefficient of the evaporation phase change process with comparable or lower pressure drop.

Tegrotenhuis, Ward E; Humble, Paul H; Lavender, Curt A; Caldwell, Dustin D

2013-12-03T23:59:59.000Z

213

Handbook of heat and mass transfer. Volume 2  

Science Conference Proceedings (OSTI)

This two-volume series, the work of more than 100 contributors, presents advanced topics in industrial heat and mass transfer operations and reactor design technology. Volume 2 emphasizes mass transfer and reactor design. Some of the contents discussed are: MASS TRANSFER PRINCIPLES - Effect of turbulence promoters on mass transfer. Mass transfer principles with homogeneous and heterogeneous reactions. Convective diffusion with reactions in a tube. Transient mass transfer onto small particles and drops. Modeling heat and mass transport in falling liquid films. Heat and mass transfer in film absorption. Multicomponent mass transfer: theory and applications. Diffusion limitation for reaction in porous catalysts. Kinetics and mechanisms of catalytic deactivation. DISTILLATION AND EXTRACTION - Generalized equations of state for process design. Mixture boiling. Estimating vapor pressure from normal boiling points of hydrocarbons. Estimating liquid and vapor molar fractions in distillation columns. Principles of multicomponent distillation. Generalized design methods for multicomponent distillation. Interfacial films in inorganic substances extraction. Liquid-liquid extraction in suspended slugs. MULTIPHASE REACTOR SYSTEMS - Reaction and mass transport in two-phase reactors. Mass transfer and kinetics in three-phase reactors. Estimating liquid film mass transfer coefficients in randomly packed columns. Designing packed tower wet scrubbers - emphasis on nitrogen oxides. Gas absorption in aerated mixers. Axial dispersion and heat transfer in gas-liquid bubble columns. Operation and design of trickle-bed reactors.

Cheremisinoff, N.P.

1986-01-01T23:59:59.000Z

214

Infrared Thermography applied to measurement of Heat transfer coefficient of water in a pipe heated by Joule effect  

E-Print Network (OSTI)

. Internal sources of heat are due to convection from flow of the heat transfer fluid through the pipes. Heat (material, diameter, spacing, and burial depth), (4) system flow rates, (5) heat transfer fluid properties · heat transfer fluid = 42% propylene glycol @ a flow rate of 350 gpm · heat pump model = Water Furnace

215

Cryogenic apparatus for study of near-field heat transfer  

Science Conference Proceedings (OSTI)

For bodies spaced in vacuum at distances shorter than the wavelength of the thermal radiation, radiative heat transfer substantially increases due to the contribution of evanescent electromagnetic waves. Experimental data on heat transfer in near-field regime are scarce. We have designed a cryogenic apparatus for the study of heat transfer over microscopic distances between metallic and non-metallic surfaces. Using a mechanical positioning system, a planeparallel gap between the samples, concentric disks, each 35 mm in diameter, is set and varied from 10{sup 0} to 10{sup 3} {mu}m. The heat transferred from the hot (10 - 100 K) to the cold sample ({approx}5 K) sinks into a liquid helium bath through a thermal resistor, serving as a heat flux meter. Transferred heat power within {approx}2 nW/cm{sup 2} and {approx}30 {mu}W/cm{sup 2} is derived from the temperature drop along the thermal resistor. For tungsten samples, the distance of the near-field effect onset was inversely proportional to temperature and the heat power increase was observed up to three orders of magnitude greater than the power of far-field radiative heat transfer.

Kralik, T.; Hanzelka, P.; Musilova, V.; Srnka, A.; Zobac, M. [Institute of Scientific Instruments of the ASCR, v.v.i., Kralovopolska 147, Brno (Czech Republic)

2011-05-15T23:59:59.000Z

216

Trace formulas for nonequilibrium Casimir interactions, heat radiation, and heat transfer for arbitrary objects  

E-Print Network (OSTI)

We present a detailed derivation of heat radiation, heat transfer, and (Casimir) interactions for N arbitrary objects in the framework of fluctuational electrodynamics in thermal nonequilibrium. The results can be expressed ...

Bimonte, Giuseppe

217

The deterioration in heat transfer to fluids at supercritical pressure and high heat fluxes  

E-Print Network (OSTI)

At slightly supercritical pressure and in the neighborhood of the pseudo-critical temperature (defined as the temperature corresponding to the peak in specific heat at the operating pressure), the heat transfer coefficient ...

Shiralkar, B. S.

1968-01-01T23:59:59.000Z

218

Heat Transfer and Fluid Mechanics - Nuclear Engineering Division (Argonne)  

NLE Websites -- All DOE Office Websites (Extended Search)

Engineering Computation Engineering Computation and Design > Heat Transfer and Fluid Mechanics Capabilities Engineering Computation and Design Engineering and Structural Mechanics Systems/Component Design, Engineering and Drafting Heat Transfer and Fluid Mechanics Overview Thermal Hydraulic Optimization of Nuclear Systems Underhood Thermal Management Combustion Simulations Advanced Model and Methodology Development Multi-physics Reactor Performance and Safety Simulations Other Capabilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Heat Transfer and Fluid Mechanics Bookmark and Share Engineering Simulation Capabilities at Argonne Nuclear Engineering Division The Engineering Simulation section specializes in the development and

219

Heat Transfer of a Multiple Helical Coil Heat Exchanger Using a Microencapsulated Phase Change Material Slurry  

E-Print Network (OSTI)

The present study has focused on the use of coil heat exchangers (CHEs) with microencapsulated phase change material (MPCM) slurries to understand if CHEs can yield greater rates of heat transfer. An experimental study was conducted using a counterflow CHE consisting of 3 helical coils. Two separate tests were conducted, one where water was used as heat transfer fluid (HTF) on the coil and shell sides, respectively; while the second one made use of MPCM slurry and water on the coil and shell sides, respectively. The NTU-effectiveness relationship of the CHE when MPCM fluid is used approaches that of a heat exchanger with a heat capacity ratio of zero. The heat transfer results have shown that when using a MPCM slurry, an increase in heat transfer rate can be obtained when compared to heat transfer results obtained using straight heat transfer sections. It has been concluded that the increased specific heat of the slurry as well as the fluid dynamics in helical coil pipes are the main contributors to the increased heat transfer.

Gaskill, Travis

2011-12-01T23:59:59.000Z

220

Measurement of flow field and local heat transfer distribution on a scraped heat exchanger crystalliser surface  

E-Print Network (OSTI)

Measurement of flow field and local heat transfer distribution on a scraped heat exchanger.ravelet@laposte.net Geert-Jan Witkamp G.J.Witkamp@xs4all.nl Abstract In a cylindrical scraped heat exchanger crystallizer exchanger surface has been studied by direct measurements of the heat exchanger surface temperature

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "radiant heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Numerical study of 2D heat transfer in a scraped surface heat exchanger  

E-Print Network (OSTI)

Numerical study of 2D heat transfer in a scraped surface heat exchanger K.-H. Sun a,*, D.L. Pyle heat exchanger with non- Newtonian power law fluids is undertaken. Numerical results are generated of scraped surface heat exchanger design are assessed in the light of the results. Ã? 2003 Elsevier Ltd. All

222

Modeling of Heat Transfer in Rooms in the Modelica Buildings Library  

E-Print Network (OSTI)

for convective and radiative heat transfer yielded a twofoldModeling of Heat Transfer in Rooms in the Modelica “of California. MODELING OF HEAT TRANSFER IN ROOMS IN THE

Wetter, Michael

2013-01-01T23:59:59.000Z

223

Rheology and Convective Heat Transfer of Colloidal Gas Aphrons in Horizontal Minichannels  

E-Print Network (OSTI)

Single-phase convective heat transfer in microchannels: aand Newell, M. E. , 1967. Heat transfer in fully developed3 /s at 130 W. Water CGA Heat Transfer Coefficient, h (W/m 2

Tseng, H.; Pilon, L.; Warrier, G.

2006-01-01T23:59:59.000Z

224

Heat-transfer dynamics during cryogen spray cooling of substrate at different initial temperatures  

E-Print Network (OSTI)

Aguilar G 2004 Radial heat transfer dynamics during cryogenof droplet dynamics and heat transfer in spray cooling Exp.S0031-9155(04)84030-2 Heat-transfer dynamics during cryogen

Jia, W; Aguilar, G; Wang, G X; Nelson, J S

2004-01-01T23:59:59.000Z

225

HEAT TRANSFER DURING THE SHOCK-INDUCED IGNITION OF AN EXPOLSIVE GAS  

E-Print Network (OSTI)

11 Stagnation Point Heat Transfer Measurements in Air atR.M. , and Kemp, N.H. , Heat Transfer from High TemperatureProceedings of the 1963 Heat Transfer and Fluid Mechanics

Heperkan, H.

2013-01-01T23:59:59.000Z

226

MEASUREMENTS OF HEAT TRANSFER TO HELIUM II AT ATMOSPHERIC PRESSURE IN A CONFINED GEOMETRY  

E-Print Network (OSTI)

M. X. Francois-:- "Heat Transfer Properties in a VerticalK. T - Tb (K) Fig. 4 . Heat transfer at the lambda point.B. The difference in the heat transfer characteristics on

Warren, R.P.

2011-01-01T23:59:59.000Z

227

Khounsary Named Associate Editor of ASME Journal of Heat Transfer  

NLE Websites -- All DOE Office Websites (Extended Search)

New Science with the APS Superconducting Undulator New Science with the APS Superconducting Undulator Young of XSD Named Associate Editor of New Journal "Structural Dynamics" The Daguerreotype and the X-ray: A Deep Look Questions Rise about Seeding For Ocean C02 Sequestration X-ray Method Shows How Frog Embryos Could Help Thwart Disease APS News Archives: 2012 | 2011 | 2010 | 2009 2008 | 2007 | 2006 | 2005 2004 | 2003 | 2002 | 2001 2000 Subscribe to APS News rss feed Khounsary Named Associate Editor of ASME Journal of Heat Transfer October 22, 2013 Bookmark and Share Ali Khounsary Ali Khounsary of the APS Engineering Support Division has been appointed as an Associate Editor of the ASME Journal of Heat Transfer. The Journal of Heat Transfer, in publication since 1879, "disseminates information of permanent interest in the areas of heat and mass transfer.

228

FEHM (Finite Element Heat and Mass Transfer Code)  

NLE Websites -- All DOE Office Websites (Extended Search)

FEHM (Finite Element Heat and Mass Transfer Code) FEHM (Finite Element Heat and Mass Transfer Code) FEHM (Finite Element Heat and Mass Transfer Code) FEHM is used to simulate groundwater and contaminant flow and transport in deep and shallow, fractured and un-fractured porous media throughout the US DOE complex. June 29, 2013 software FEHM is used to simulate groundwater and contaminant flow and transport in deep and shallow, fractured and un-fractured porous media throughout the US DOE complex. Available for thumbnail of Feynman Center (505) 665-9090 Email FEHM (Finite Element Heat and Mass Transfer Code) FEHM is used to simulate groundwater and contaminant flow and transport in deep and shallow, fractured and un-fractured porous media throughout the US DOE complex. FEHM has proved to be a valuable asset on a variety of

229

Design and fabrication of heat transfer surfaces from superplastic material  

Science Conference Proceedings (OSTI)

The production of complex heat transfer surfaces (i.e., those without straight fins) is restricted by available fabrication techniques, materials, geometries, and cost. Based on the superplastic sheet thermoforming process, a new technique for fabricating ...

J. B. Randolph; F. K. King

1972-05-01T23:59:59.000Z

230

Survey and evaluation of techniques to augment convective heat transfer  

E-Print Network (OSTI)

This report presents a survey and evaluation of the numerous techniques which have been shown to augment convective heat transfer. These techniques are: surface promoters, including roughness and treatment; displaced ...

Bergles A. E.

1965-01-01T23:59:59.000Z

231

Heat transfer during film condensation of a liquid metal vapor  

E-Print Network (OSTI)

The object of this investigation is to resolve the discrepancy between theory and experiment for the case of heat transfer durirnfilm condensation of liquid metal vapors. Experiments by previous investigators have yielded ...

Sukhatme, S. P.

1964-01-01T23:59:59.000Z

232

Investigation of 3-D Heat Transfer Effects in Fenestration Products.  

E-Print Network (OSTI)

??ABSTRACT INVESTIGATION OF 3-D HEAT TRANSFER EFFECTS IN FENESTRATION PRODUCTS SEPTEMBER 2010 SNEH KUMAR B. TECH., INDIAN INSTITUTE OF TECHNOLOGY, CHENNAI INDIA M.S.M.E., UNIVERSITY OF… (more)

Kumar, Sneh

2010-01-01T23:59:59.000Z

233

High Operating Temperature Heat Transfer Fluids for Solar Thermal...  

NLE Websites -- All DOE Office Websites (Extended Search)

Heat Transfer Fluids for Solar Thermal Power Generation UCLA, UCB, Yale Award Number: DE-EE0005941 | January 9, 2013 | Sungtaek Ju 1.1 Thermochemistry modeling Identified promising...

234

Wind heat transfer coefficient in solar collectors in outdoor conditions  

Science Conference Proceedings (OSTI)

Knowledge of wind heat transfer coefficient, h{sub w}, is required for estimation of upward losses from the outer surface of flat plate solar collectors/solar cookers. In present study, an attempt has been made to estimate the wind induced convective heat transfer coefficient by employing unglazed test plate (of size about 0.9 m square) in outdoor conditions. Experiments, for measurement of h{sub w}, have been conducted on rooftop of a building in the Institute campus in summer season for 2 years. The estimated wind heat transfer coefficient has been correlated against wind speed by linear regression and power regression. Experimental values of wind heat transfer coefficient estimated in present work have been compared with studies of other researchers after normalizing for plate length. (author)

Kumar, Suresh; Mullick, S.C. [Centre for Energy Studies, Indian Institute of Technology, Delhi, Hauz Khas, New Delhi 110 016 (India)

2010-06-15T23:59:59.000Z

235

Aspects of Heat Transfer During Production of Remelt Ingot Using ...  

Science Conference Proceedings (OSTI)

Sep 1, 2001 ... Aspects of Heat Transfer During Production of Remelt Ingot Using Chain Casters by J.E Grandfield, TT Nguyen, G. Redden and J.A. Taylor ...

236

Enhancement of heat transfer for ground source heat pump systems.  

E-Print Network (OSTI)

??Uptake of geothermal heat pump (GSHP) systems has been slow in some parts of the world due to the unpredictable operational performance, large installation space… (more)

Mori, Hiromi

2010-01-01T23:59:59.000Z

237

On Water Flow in Hot Fractured Rock -- A Sensitivity Study on the Impact of Fracture-Matrix Heat Transfer  

E-Print Network (OSTI)

is related to the heat transfer between the two phasespossibly be affected. Heat transfer from the matrix can beof Fracture-Matrix Heat Transfer Jens T. Birkholzer and

Birkholzer, Jens T.; Zhang, Yingqi

2005-01-01T23:59:59.000Z

238

Thermal single-well injection-withdrawal tracer tests for determining fracture-matrix heat transfer area  

E-Print Network (OSTI)

Testing for Estimating Heat Transfer Area in FracturedFRACTURE-MATRIX HEAT TRANSFER AREA Karsten Pruess andimprove the flow and heat transfer characteristics of the

Pruess, K.

2011-01-01T23:59:59.000Z

239

Two-Dimensional Computational Fluid Dynamics and Conduction Simulations of Heat Transfer in Horizontal Window Frames with Internal Cavities  

E-Print Network (OSTI)

the two-dimensional heat transfer through building products.Gustavsen, A. 2001. Heat transfer in window frames withand CFD Simulations of Heat Transfer in Horizontal Window

Gustavsen, Arlid

2008-01-01T23:59:59.000Z

240

A unified numerical framework model for simulating flow, transport, and heat transfer in porous and fractured media  

E-Print Network (OSTI)

Flow, Transport, and Heat Transfer in Porous and Fracturedtransport, and heat transfer in porous and fracturedflow, chemical transport, and heat transfer in rock. These

Wu, Yu-Shu

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "radiant heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

A unified numerical framework model for simulating flow, transport, and heat transfer in porous and fractured media  

E-Print Network (OSTI)

transport, and heat transfer processes in porous media. 2.1.mass transport, and heat-transfer processes through porousinvolved. These heat-transfer processes are complicated by

Wu, Yu-Shu

2004-01-01T23:59:59.000Z

242

Handbook of single-phase convective heat transfer  

Science Conference Proceedings (OSTI)

This book presents a comprehensive collection of convective heat transfer basics, methods of calculations, tables, charts and design parameters involving single-phase flows - the most commonly experienced mode in heat transfer problems. Topics covered include natural and forced convection under a wise variety of design conditions, such as ducts, crossflows, turbulent conditions, transitional states, curved and coiled ducts, over rods in metals and through bends, valves and fittings. The book provides sections on radiation interaction and fouling conditions.

Kakac, S.; Shah, R.K.; Aung, W.

1987-01-01T23:59:59.000Z

243

Advanced turbine cooling, heat transfer, and aerodynamic studies  

DOE Green Energy (OSTI)

The contractual work is in three parts: Part I - Effect of rotation on enhanced cooling passage heat transfer, Part II - Effect of Thermal Barrier Coating (TBC) spallation on surface heat transfer, and Part III - Effect of surface roughness and trailing edge ejection on turbine efficiency under unsteady flow conditions. Each section of this paper has been divided into three parts to individually accommodate each part. Part III is further divided into Parts IIIa and IIIb.

Han, Je-Chin; Schobeiri, M.T. [Texas A & M Univ., College Station, TX (United States). Dept. of Mechanical Engineering

1995-12-31T23:59:59.000Z

244

Mpemba effect, Newton cooling law and heat transfer equation  

E-Print Network (OSTI)

In this work we suggest a simple theoretical solution of the Mpemba effect in full agreement with known experimental data. This solution follows simply as an especial approximation (linearization) of the usual heat (transfer) equation, precisely linearization of the second derivation of the space part of the temperature function (as it is well-known Newton cooling law can be considered as the effective approximation of the heat (transfer) equation for constant space part of the temperature function).

Vladan Pankovic; Darko V. Kapor

2010-05-06T23:59:59.000Z

245

Literature survey of heat transfer enhancement techniques in refrigeration applications  

Science Conference Proceedings (OSTI)

A survey has been performed of the technical and patent literature on enhanced heat transfer of refrigerants in pool boiling, forced convection evaporation, and condensation. Extensive bibliographies of the technical literature and patents are given. Many passive and active techniques were examined for pure refrigerants, refrigerant-oil mixtures, and refrigerant mixtures. The citations were categorized according to enhancement technique, heat transfer mode, and tube or shell side focus. The effects of the enhancement techniques relative to smooth and/or pure refrigerants were illustrated through the discussion of selected papers. Patented enhancement techniques also are discussed. Enhanced heat transfer has demonstrated significant improvements in performance in many refrigerant applications. However, refrigerant mixtures and refrigerant-oil mixtures have not been studied extensively; no research has been performed with enhanced refrigerant mixtures with oil. Most studies have been of the parametric type; there has been inadequate examination of the fundamental processes governing enhanced refrigerant heat transfer, but some modeling is being done and correlations developed. It is clear that an enhancement technique must be optimized for the refrigerant and operating condition. Fundamental processes governing the heat transfer must be examined if models for enhancement techniques are to be developed; these models could provide the method to optimize a surface. Refrigerant mixtures, with and without oil present, must be studied with enhancement devices; there is too little known to be able to estimate the effects of mixtures (particularly NARMs) with enhanced heat transfer. Other conclusions and recommendations are offered.

Jensen, M.K.; Shome, B. [Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Mechanical Engineering, Aeronautical Engineering and Mechanics

1994-05-01T23:59:59.000Z

246

Boiling heat transfer in a hydrofoil-based micro pin fin heat sink  

E-Print Network (OSTI)

-flow boiling over circular tube bundles has been meticulously studied; collected data and correlations for circular tube bundles. For exam- ple, Jensen and Hsu [81] conducted a parametric study of boiling heat transfer in a horizontal tube bundle and reported an increase in local heat transfer coefficient

Peles, Yoav

247

Developing Low-Conductance Window Frames: Capabilities and Limitations of Current Window Heat Transfer Design Tools  

E-Print Network (OSTI)

internal cavities the heat transfer process is more complex,heat transfer in these “insulated” zones could be used in the design process

Gustavsen, Arild

2009-01-01T23:59:59.000Z

248

Research on Convective Heat Transfer and Mass Transfer of the Evaporator in Micro/Mini-Channel  

E-Print Network (OSTI)

With the development of science and technology, various heating and cooling equipment have a development trend of micromation. Micro-fabrication processes make it possible to conduct research on condensation heat transfer in micro-channels. Based on the reviewers on the present household air conditioners, the potential requirements for new heat transfer enhancement used for household air conditioners are discussed. Investigations on condensation and boiling of refrigerants in mini/micro channels have indicated that the evaporator and condenser of air conditioner would be more efficient and more compact by using microchannels, and hence it could improve the coefficient of performance of air conditioners to meet the new energy conversion standards in China. The relationship between condensation heat transfer of refrigerants and surface physical characteristics of the evaporator are pointed out and analyzed in order to achieving the corresponding heat transfer coefficients.

Su, J.; Li, J.

2006-01-01T23:59:59.000Z

249

Effect of attic ventilation on the performance of radiant barriers  

Science Conference Proceedings (OSTI)

The objective of the experiments was to quantify how attic ventilation would affect the performance of a radiant barrier. Ceiling heat flux and space cooling load were both measured. Results of side-by-side radiant barrier experiments using two identical 13.38 m[sup 2] (nominal) test houses are presented in this paper. The test houses responded similarly to weather variations. Indoor temperatures of the test houses were controlled to within 0.2 [degrees] C. Ceiling heat fluxes and space cooling load were within a 2.5 percent difference between both test houses. The results showed that a critical attic ventilation flow rate of 1.3 (1/sec)/m[sup 2] of the attic floor existed after which the percentage reduction in ceiling heat fluxes produced by the radiant barriers did not change with increasing attic airflow rates. The ceiling heat flux reductions produced by the radiant barriers were between 25 and 35 percent, with 28 percent being the percent reduction observed most often in the presence of attic ventilation. The space-cooling load reductions observed were between two to four percent. All results compiled in this paper were for attics with unfaced fiberglass insulation with a resistance level of 3.35 m[sup 2]K/W (nominal) and for a perforated radiant barrier with low emissivities (less than 0.05) on both sides.

Medina, M.A.; O'Neal, D.L. (Texas A and M Univ., College Station, TX (United States). Dept. of Mechanical Engineering); Turner, W.D. (Texas A and M Univ., College Station, TX (United States). Coll. of Engineering)

1992-11-01T23:59:59.000Z

250

Pool boiling heat transfer characteristics of nanofluids  

E-Print Network (OSTI)

Nanofluids are engineered colloidal suspensions of nanoparticles in water, and exhibit a very significant enhancement (up to 200%) of the boiling Critical Heat Flux (CHF) at modest nanoparticle concentrations (50.1% by ...

Kim, Sung Joong, Ph. D. Massachusetts Institute of Technology

2007-01-01T23:59:59.000Z

251

Molecular Dynamics Method in Microscale Heat Transfer Shigeo Maruyama  

E-Print Network (OSTI)

1 Molecular Dynamics Method in Microscale Heat Transfer Shigeo Maruyama Department of Mechanical://www.photon.t.u-tokyo.ac.jp/~maruyama/ 1. INTRODUCTION Molecular level understandings are becoming more important and molecular based to take account of nuclei in size of molecular clusters. The effect of the surfactant on the heat and mass

Maruyama, Shigeo

252

Heat Transfer Laboratory of the Savannah River Laboratory  

SciTech Connect

The Heat Transfer Laboratory, recently- constructed adjacent to the main Savannah River Laboratory building, was designed to mock up nuclear heating and cooling of reactor components under a variety- of conditions. Nuclear heating is simulated by electrical resistance heating of test sections with a 3 MW directcurrent power supply. Cooling is provided by water. Three test stations (A, B, and C) are available for testing full-size fuel assemblies, measuring flow instabilities, and for measuring burnout heat fluxes. Safeguards provided in the design of the facility and conservative operating procedures minimize or elimnate potential hazards. (auth)

Knoebel, D.H.; Harris, S.D.

1973-10-01T23:59:59.000Z

253

Non-equilibrium electromagnetic fluctuations: Heat transfer and interactions  

E-Print Network (OSTI)

The Casimir force between arbitrary objects in equilibrium is related to scattering from individual bodies. We extend this approach to heat transfer and Casimir forces in non-equilibrium cases where each body, and the environment, is at a different temperature. The formalism tracks the radiation from each body and its scatterings by the other objects. We discuss the radiation from a cylinder, emphasizing its polarized nature, and obtain the heat transfer between a sphere and a plate, demonstrating the validity of proximity transfer approximation at close separations and arbitrary temperatures.

Matthias Krüger; Thorsten Emig; Mehran Kardar

2011-02-18T23:59:59.000Z

254

Active heat transfer enhancement in integrated fan heat sinks  

E-Print Network (OSTI)

Modern computer processors require significant cooling to achieve their full performance. The "efficiency" of heat sinks is also becoming more important: cooling of electronics consumes 1% of worldwide electricity use by ...

Staats, Wayne Lawrence

2012-01-01T23:59:59.000Z

255

Modulation of near-field heat transfer between two gratings  

E-Print Network (OSTI)

We present a theoretical study of near-field heat transfer between two uniaxial anisotropic planar structures. We investigate how the distance and relative orientation (with respect to their optical axes) between the objects affect the heat flux. In particular, we show that by changing the angle between the optical axes it is possible in certain cases to modulate the net heat flux up to 90% at room temperature, and discuss possible applications of such a strong effect.

Svend-Age Biehs; Felipe S. S. Rosa; Philippe Ben-Abdallah

2011-05-18T23:59:59.000Z

256

Design and operation of solar thermal heat transfer systems  

Science Conference Proceedings (OSTI)

The importance of heat transfer systems in the collection and use of solar energy is discussed. The success or failure of many solar energy systems has been determined by the design of the heat transfer system. This report includes a short summary of some of the DOE sponsored solar industrial process heat sites. From the design, construction, and operation of these systems many lessons were learned which will be important to designers and potential users of solar thermal systems. Also included is a discussion of solar collector foundation over-design that has increased the collector system costs.

Rush, E.E.

1985-01-01T23:59:59.000Z

257

Curvature dependence of the interfacial heat and mass transfer coefficients  

E-Print Network (OSTI)

Nucleation is often accompanied by heat transfer between the surroundings and a nucleus of a new phase. The interface between two phases gives an additional resistance to this transfer. For small nuclei the interfacial curvature is high, which affects not only equilibrium quantities such as surface tension, but also the transport properties. In particular, high curvature affects the interfacial resistance to heat and mass transfer. We develop a framework for determining the curvature dependence of the interfacial heat and mass transfer resistances. We determine the interfacial resistances as a function of a curvature. The analysis is performed for a bubble of a one-component fluid and may be extended to various nuclei of multicomponent systems. The curvature dependence of the interfacial resistances is important in modeling transport processes in multiphase systems.

K. S. Glavatskiy; D. Bedeaux

2013-10-11T23:59:59.000Z

258

Heat Transfer Enhancement in Separated and Vortex Flows  

SciTech Connect

This document summarizes the research performance done at the Heat Transfer Laboratory of the University of Minnesota on heat transfer and energy separation in separated and vortex flow supported by DOE in the period September 1, 1998--August 31, 2003. Unsteady and complicated flow structures in separated or vortex flows are the main reason for a poor understanding of heat transfer under such conditions. The research from the University of Minnesota focused on the following important aspects of understanding such flows: (1) Heat/mass transfer from a circular cylinder; (2) study of energy separation and heat transfer in free jet flows and shear layers; and (3) study of energy separation on the surface and in the wake of a cylinder in crossflow. The current study used three different experimental setups to accomplish these goals. A wind tunnel and a liquid tunnel using water and mixtures of ethylene glycol and water, is used for the study of prandtl number effect with uniform heat flux from the circular cylinder. A high velocity air jet is used to study energy separation in free jets. A high speed wind tunnel, same as used for the first part, is utilized for energy separation effects on the surface and in the wake of the circular cylinder. The final outcome of this study is a substantial advancement in this research area.

Richard J. Goldstein

2004-05-27T23:59:59.000Z

259

Hydronic Radiant Cooling Systems  

NLE Websites -- All DOE Office Websites (Extended Search)

4 4 Hydronic Radiant Cooling Systems Cooling nonresidential buildings in the U.S. contributes significantly to electrical power consumption and peak power demand. Part of the electrical energy used to cool buildings is drawn by fans transporting cool air through the ducts. The typical thermal cooling peak load component for California office buildings can be divided as follows: 31% for lighting, 13% for people, 14% for air transport, and 6% for equipment (in the graph below, these account for 62.5% of the electrical peak load, labeled "chiller"). Approximately 37% of the electrical peak power is required for air transport, and the remainder is necessary to operate the compressor. DOE-2 simulations for different California climates using the California

260

TRANSIENT HEAT TRANSFER IN REACTOR COOLANT CHANNELS  

SciTech Connect

An analysis is presented of the transient behavior of a generalized cooiant channel neglecting temperature dependent reactivity changes. The analysis is applicable to forced convection cooling of heterogeneous reactor fuel elements or electrically heated simulation thereof. Derivations are given for cases of variation of coolant inlet temperature and of heat generation. An approximation is also developed applicable to thin fuel elements. From this, solutions are obtained for cases-of impulsive, step, linear, and step-exponential variations of inlet temperature, and, of impulsive and uniform variations of heat generation. The solutions presented will be of use during preliminary stages of design of new heterogeneous reactor concepts (when the use of computing machines may not be warranted), and, in the design and interpretation of transient experiments simulating reactor fuel channels. (auth)

Stein, R.P.

1957-10-31T23:59:59.000Z

Note: This page contains sample records for the topic "radiant heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Heat Transfer Enhancement for Finned-Tube Heat Exchangers with Vortex Generators: Experimental and Numerical Results  

Science Conference Proceedings (OSTI)

A combined experimental and numerical investigation is under way to investigate heat transfer enhancement techniques that may be applicable to large-scale air-cooled condensers such as those used in geothermal power applications. The research is focused on whether air-side heat transfer can be improved through the use of finsurface vortex generators (winglets,) while maintaining low heat exchanger pressure drop. A transient heat transfer visualization and measurement technique has been employed in order to obtain detailed distributions of local heat transfer coefficients on model fin surfaces. Pressure drop measurements have also been acquired in a separate multiple-tube row apparatus. In addition, numerical modeling techniques have been developed to allow prediction of local and average heat transfer for these low-Reynolds-number flows with and without winglets. Representative experimental and numerical results presented in this paper reveal quantitative details of local fin-surface heat transfer in the vicinity of a circular tube with a single delta winglet pair downstream of the cylinder. The winglets were triangular (delta) with a 1:2 height/length aspect ratio and a height equal to 90% of the channel height. Overall mean fin-surface Nusselt-number results indicate a significant level of heat transfer enhancement (average enhancement ratio 35%) associated with the deployment of the winglets with oval tubes. Pressure drop measurements have also been obtained for a variety of tube and winglet configurations using a single-channel flow apparatus that includes four tube rows in a staggered array. Comparisons of heat transfer and pressure drop results for the elliptical tube versus a circular tube with and without winglets are provided. Heat transfer and pressure-drop results have been obtained for flow Reynolds numbers based on channel height and mean flow velocity ranging from 700 to 6500.

O'Brien, James Edward; Sohal, Manohar Singh; Huff, George Albert

2002-08-01T23:59:59.000Z

262

Cooling load differences between radiant and air systems  

E-Print Network (OSTI)

the differences of the heat transfer process in zonesto capture detailed heat transfer processes in the zones and

Feng, Jingjuan Dove; Schiavon, Stefano; Bauman, Fred

2013-01-01T23:59:59.000Z

263

Heat Transfer in Superfluids: Effect of Gravity  

E-Print Network (OSTI)

We discuss the influence of an external field on energy transport in superfluid. He-II is not isothermal in presence of Earth gravity; instead, it supports finite temperature gradient given by a Fourier-like equation. We calculate asymptotic behavior of the effective heat resistance in the vicinity of the $\\lambda$-transition.

L. A. Melnikovsky

2004-05-19T23:59:59.000Z

264

Aspects of forced convective heat transfer in geothermal systems  

DOE Green Energy (OSTI)

A knowledge of convective heat transfer is essential to understanding geothermal systems and other systems of moving groundwater. A simple, kinematic approach toward convective heat transfer is taken here. Concern is not with the cause of the groundwater motion but only with the fact that the water is moving and transferring heat. The mathematical basis of convective heat transfer is the energy equation which is a statement of the first law of thermodynamics. The general solution of this equation for a specific model of groundwater flow has to be done numerically. The numerical algorithm used here employs a finite difference approximation to the energy equation that uses central differences for the heat conduction terms and one-sided differences for the heat convection terms. Gauss--Seidel iteration is then used to solve the finite difference equation at each node of a non-uniform mesh. The Monroe and Red Hill hot springs, a small hydrothermal system in central Utah, provide an example to illustrate the application of convective heat transfer theory to a geophysical problem. Two important conclusions regarding small geothermal systems follow immediately from the results of this application. First, the most rapid temperature rise in the convecting part of a geothermal system is near the surface. Below this initially rapid temperature increase the temperature increases very slowly, and thus temperatures extrapolated from shallow boreholes can be seriously in error. Second, the temperatures and heat flows observed at Monroe and Red Hill, and probably at many other small geothermal areas, can easily result from moderate vertical groundwater velocities in faults and fracture zones in an area of normal heat flow.

Kilty, K.; Chapman, D.S.; Mase, C.

1978-07-01T23:59:59.000Z

265

Thermodynamics of enhanced heat transfer: a model study  

E-Print Network (OSTI)

Situations where a spontaneous process of energy or matter transfer is enhanced by an external device are widespread in nature (human sweating system, enzyme catalysis, facilitated diffusion across bio-membranes, industrial heat exchangers). The thermodynamics of such processes remains however open. Here we study enhanced heat transfer by a model junction immersed between two thermal baths at different temperatures $T_h$ and $T_c$ ($T_h>T_c$). The transferred heat power is enhanced via controlling the junction by means of external time-dependent fields. Provided that the spontaneous heat flow process is optimized over the junction Hamiltonian, any enhancement of this spontaneous process does demand consumption and subsequent dissipation of work. The efficiency of enhancement is defined via the increment in the heat power divided over the amount of consumed work. We show that this efficiency is bounded from above by $T_c/(T_h-T_c)$. Formally this is identical to the Carnot bound for the efficiency of ordinary refrigerators which transfer heat from cold to hot. It also shares some (but not all) physical features of the Carnot bound.

Karen Hovhannisyan; Armen E. Allahverdyan

2010-07-20T23:59:59.000Z

266

Spray cooling heat-transfer with subcooled trichlorotrifluoroethane (Freon-113) for vertical constant heat flux surfaces  

SciTech Connect

Experiments were done using subcooled Freon-113 sprayed vertically downward. Local and average heat transfers were investigated fro Freon-113 sprays with 40 C subcooling, droplet sizes 200-1250{mu}m, and droplet breakup velocities 5-29 m/s. Full-cone type nozzles were used to generate the spray. Test assemblies consisted of 1 to 6 7.62 cm vertical constant heat flux surfaces parallel with each other and aligned horizontally. Distance between heated surfaces was varied from 6.35 to 76.2 mm. Steady state heat fluxes as high as 13 W/cm{sup 2} were achieved. Dependence on the surface distance from axial centerline of the spray was found. For surfaces sufficiently removed from centerline, local and average heat transfers were identical and correlated by a power relation of the form seen for normal-impact sprays which involves the Weber number, a nondimensionalized temperature difference, and a mass flux parameter. For surfaces closer to centerline, the local heat transfer depended on vertical location on the surface while the average heat transfer was described by a semi-log correlation involving the same parameters. The heat transfer was independent of the distance (gap) between the heated surfaces for the gaps investigated.

Kendall, C.M. [Lawrence Livermore National Lab., CA (United States); Holman, J.P. [Southern Methodist Univ., Dallas, TX (United States). Dept. of Mechanical Engineering

1996-06-06T23:59:59.000Z

267

Convective heat transfer inside passive solar buildings  

DOE Green Energy (OSTI)

Natural convection between spaces in a building can play a major role in energy transfer. Two situations are investigated: convection through a single doorway into a remote room, and a convective loop in a two-story house with a south sunspace where a north stairway serves as the return path. A doorway-sizing equation is given for the single-door case. Detailed data are given from the monitoring of airflow in one two-story house and summary data are given for five others. Observations on the nature of the airflow and design guidelines are presented.

Jones, R.W.; Balcomb, J.D.; Yamaguchi, K.

1983-01-01T23:59:59.000Z

268

Preliminary Heat Transfer Studies for the Double Shell Tanks (DST) Transfer Piping  

SciTech Connect

Heat transfer studies were made to determine the thermal characteristics of double-shell tank transfer piping under both transient and steady-state conditions. A number of design and operation options were evaluated for this piping system which is in its early design phase.

HECHT, S.L.

2000-02-15T23:59:59.000Z

269

Radiant energy collector. [Patent application  

DOE Patents (OSTI)

A cylindrical radiant energy collector is provided which includes a reflector spaced apart from an energy absorber. The reflector is of a particular shape which ideally eliminates gap losses.

McIntire, W.R.

1980-02-14T23:59:59.000Z

270

ORNL Radiant Barrier - ETSD Division  

NLE Websites -- All DOE Office Websites (Extended Search)

in Zone 2), radiant barriers could reduce your utility bills by as much as 150 per year using average residential electricity prices. If you're able to participate in one of...

271

Dispersed-Flow Film Boiling Heat Transfer Data near Spacer Grids in a Rod Bundle  

Science Conference Proceedings (OSTI)

Technical Paper / Radiation Effects and Their Relationship to Geological Repository / Heat Transfer and Fluid Flow

Graydon L. Yoder; Jr.; David G. Morris; Charles B. Mullins; Larry J. Ott

272

Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump  

DOE Patents (OSTI)

Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use, as the heat transfer medium, the working fluid of the absorption system taken from the generator at a location where the working fluid has a rich liquor concentration.

Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI)

1998-07-21T23:59:59.000Z

273

MODELING OF HEAT TRANSFER IN ROOMS IN THE MODELICA  

NLE Websites -- All DOE Office Websites (Extended Search)

MODELING MODELING OF HEAT TRANSFER IN ROOMS IN THE MODELICA "BUILDINGS" LIBRARY Michael Wetter, Wangda Zuo, Thierry Stephane Nouidui Simulation Research Group, Building Technologies Department Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory Berkeley, CA 94720, USA ABSTRACT This paper describes the implementation of the room heat transfer model in the free open-source Modelica "Buildings" library. The model can be used as a single room or to compose a multizone building model. We discuss how the model is de- composed into submodels for the individual heat transfer phenomena. We also discuss the main physical assumptions. The room model can be parameterized to use di↵erent modeling assump- tions, leading to linear or non-linear di↵erential algebraic systems of equations. We present nu- merical experiments that show

274

THERM: Two-Dimensional Building Heat-Transfer Modeling  

NLE Websites -- All DOE Office Websites (Extended Search)

5 5 THERM: Two-Dimensional Building Heat-Transfer Modeling For more information and to download THERM, please visit our website: http://windows.lbl.gov/software/therm The Windows and Daylighting Group's two-year-old computer program THERM 1.0 is a state-of-the-art tool for modeling two-dimensional heat-transfer effects in building components. The thermal property information THERM provides is important for the design and application of building components such as windows, walls, foundations, roofs and doors. This Microsoft Windows-based program has great potential to users such as building component manufacturers, educators, students, architects, engineers and others who are interested in assessing the heat-transfer properties of single products, product interactions, or integrated systems. THERM

275

Heat Transfer in Projecting and Sloped Fenestration Products  

NLE Websites -- All DOE Office Websites (Extended Search)

Heat Transfer in Projecting and Sloped Fenestration Products Heat Transfer in Projecting and Sloped Fenestration Products Speaker(s): Dragan Charlie Curcija Date: May 26, 2010 - 12:00pm Location: 90-3122 The heat transfer performance of fenestration products is routinely determined using computer simulations combined with physical testing. Initial efforts to develop simulation and test procedures for the fenestration products in the 1980's focused on simple planar windows since they are the dominant share of the market. However, once these procedures were developed (with resulting ISO standards and national rating and labeling requirements), manufacturers of more physically complex fenestration products (skylights, green house windows, tubular skylights) demanded procedures for simulating and testing their products. Dr Curcija

276

FEHM: finite element heat and mass transfer code  

DOE Green Energy (OSTI)

The finite element heat and mass (FEHM) transfer code is a computer code developed to simulate geothermal and hot dry rock reservoirs. It is also applicable to natural-state studies of geothermal systems and ground-water flow. It solves the equations of heat and mass transfer for multiphase flow in porous and permeable media using the finite element method. The code also has provisions for a noncoupled tracer; that is, the tracer solutions do not affect the heat and mass transfer solutions. It can simulate two-dimensional, two-dimensional radial, or three-dimensional geometries. A summary of the equations in the model, the numerical solution procedure, and model verification and validation are provided in this report. A user's guide and sample problems are included in the appendices. 17 refs., 10 figs., 4 tabs.

Zyvoloski, G.; Dash, Z.; Kelkar, S.

1988-03-01T23:59:59.000Z

277

Heat and mass transfer analysis of a desiccant dehumidifier matrix  

DOE Green Energy (OSTI)

This report documents the SERI Single-Blow Test Facility's design, fabrication, and testing for characterizing desiccant dehumidifiers for solar cooling applications. The first test article, a silica-gel parallel-plate dehumidifier with highly uniform passages, was designed and fabricated. Transient heat and mass transfer data and pressure drop data across the dehumidifier were obtained. Available heat and mass transfer models were extended to the parallel-place geometry, and the experimental data were compared with model predictions. Pressure drop measurements were also compared with model predictions of the fully developed laminar flow theory. The comparisons between the lumped-capacitance model and the experimental data were satisfactory. The pressure drop data compared satisfactorily with the theory (within 15%). A solid-side resistance model that is more detailed and does not assume symmetrical diffusion in particles was recommended for performance. This study has increased our understanding of the heat and mass transfer in silica gel parallel-plate dehumidifiers.

Pesaran, A.A.

1986-07-01T23:59:59.000Z

278

Heat transfer characteristics of a three-phase volume boiling direct contact heat exchanger  

DOE Green Energy (OSTI)

The advantages of direct contact heat transfer over heat transfer utilizing conventional metallic heat exchangers are listed. The performance characteristics of a three-phase direct contact heat exchanger in near counterflow operation were evaluated using water as the continuous phase fluid and refrigerant 113 as the dispersed phase fluid. Conclusions are drawn from the results having to do with refrigerant injection technique, vessel operating height, mass flow rate of refrigerant, water inlet temperature, operation at pinch point temperature differences below 13 to 20/sup 0/C, and operation with a dispersed phase fluid less dense than water. (MHR)

Blair, C.K.; Boehm, R.F.; Jacobs, H.R.

1976-03-01T23:59:59.000Z

279

Exploring the Limits of Boiling and Evaporative Heat Transfer Using Micro/Nano Structures  

E-Print Network (OSTI)

Heat Transfer Using Micro/Nano Structures by Ming-Chang Lu AHeat Transfer Using Micro/Nano Structures Copyright 2010 byHeat Transfer Using Micro/Nano Structures by Ming-Chang Lu

Lu, Ming-Chang

2010-01-01T23:59:59.000Z

280

AN EXPERIMENTAL INVESTIGATION ON HEAT TRANSFER CHARACTERISTICS OF AIR AND CO2 IN MICROTUBES  

E-Print Network (OSTI)

by a cooling capacity, which is delivered in those rooms by heat exchangers where a heat transfer fluid - 2 and Fluid Science, 1-3:17. Mortada S., 2010. "Heat transfer performance of a mini-channel evaporator are mini-channel heat exchangers (MCHE) combining high heat transfer coefficients and low refrigerant

Kandlikar, Satish

Note: This page contains sample records for the topic "radiant heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Thermal Hydraulic Optimization of Nuclear Systems [Heat Transfer and Fluid  

NLE Websites -- All DOE Office Websites (Extended Search)

Thermal Hydraulic Thermal Hydraulic Optimization of Nuclear Systems Capabilities Engineering Computation and Design Engineering and Structural Mechanics Systems/Component Design, Engineering and Drafting Heat Transfer and Fluid Mechanics Overview Thermal Hydraulic Optimization of Nuclear Systems Underhood Thermal Management Combustion Simulations Advanced Model and Methodology Development Multi-physics Reactor Performance and Safety Simulations Other Capabilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Heat Transfer and Fluid Mechanics Bookmark and Share Thermal Hydraulic Optimization of Nuclear Systems Accelerator Driven Test Facility Target Accelerator Driven Test Facility Target. Click on image to view larger

282

Underhood Thermal Management [Heat Transfer and Fluid Mechanics] - Nuclear  

NLE Websites -- All DOE Office Websites (Extended Search)

Underhood Thermal Underhood Thermal Management Capabilities Engineering Computation and Design Engineering and Structural Mechanics Systems/Component Design, Engineering and Drafting Heat Transfer and Fluid Mechanics Overview Thermal Hydraulic Optimization of Nuclear Systems Underhood Thermal Management Combustion Simulations Advanced Model and Methodology Development Multi-physics Reactor Performance and Safety Simulations Other Capabilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Heat Transfer and Fluid Mechanics Bookmark and Share Underhood Thermal Management Hybrid Vehicle Underhood Thermal Analysis Hybrid Vehicle Underhood Thermal Analysis. Click on image to view larger image. In addition to nuclear system applications, the section applies its

283

Advanced Model and Methodology Development [Heat Transfer and Fluid  

NLE Websites -- All DOE Office Websites (Extended Search)

Advanced Model and Advanced Model and Methodology Development Capabilities Engineering Computation and Design Engineering and Structural Mechanics Systems/Component Design, Engineering and Drafting Heat Transfer and Fluid Mechanics Overview Thermal Hydraulic Optimization of Nuclear Systems Underhood Thermal Management Combustion Simulations Advanced Model and Methodology Development Multi-physics Reactor Performance and Safety Simulations Other Capabilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Heat Transfer and Fluid Mechanics Bookmark and Share Advanced Model and Methodology Development Electrorefiner Model for Treatment of Spent Nuclear Fuel Electrorefiner Model for Treatment of Spent Nuclear Fuel. Click on image to

284

Heat transfer education : Keeping it relevant and vibrant.  

SciTech Connect

The motivation for a fresh look at heat transfer education, both in content and in methodology, is generated by a number of trends in engineering practice. These include the increasing demand for engineers with interdisciplinary skills, rapid integration of technology, emergence of computerized and interactive problem-solving tools, shortening time of concept-to-market, availability of new technologies, and an increasing number of new or redesigned products and processes in which heat transfer plays a part. Examination of heat transfer education in this context can be aided by considering the changes, both qualitatively and quantitatively, in the student, educator, and researcher populations, employment opportunities, in the needs of corporations, government, industry, and universities, and in the relevant technical problems and issues of the day. Such an overview provides the necessary background for charting a response to the difficult question of how to maintain excellence and continuity in heat transfer education in the face of rapid, widespread, and complex changes. The present paper addresses how to make heat transfer education more relevant and stimulating. This paper represents a written summary of a 1996 panel discussion at the 1996 International Mechanical Engineering Conference and Exhibition (IMECE) of the American Society of Mechanical Engineers (ASME) in Atlanta, Georgia, on ''Heat Transfer Education: Keeping it Relevant and Vibrant,'' with significant expansion and amplification by the authors and the panelists in the 1997-98 period. The consensus of the participants is that the steps necessary to ensure the desired outcome in heat transfer education should include: (1) a better understanding of the interaction between the student, course content, and market needs; (2) an appreciation of the need in multidisciplinary industrial environments for engineers trained with a broad background: (3) a revision of the introductory heat transfer course to incorporate illustrative and insightful industrial examples and case studies reducible to order-of-magnitude analyses; (4) a reinforcement of real-world problem-solving abilities in students by introducing them to examples that emphasize multidisciplinary issues in modern thermal management problems and finally (5) industrial collaboration that would provide the educator with meaningful thermal management case studies (and possible funding), the student with an appreciation of industrial practices, and the industrial sponsor with access to academia for assistance in problem solving. Also suggested is an effective regular review program to provide assessment, feedback, and suggestions for quality control to interested institutions on their teaching methodology and materials.

Khounsary, A. M.

1998-08-14T23:59:59.000Z

285

Enhancement and suppression of heat transfer by MHD turbulence  

E-Print Network (OSTI)

We study of the effect of turbulence on heat transfer within magnetized plasmas for energy injection velocities both larger and smaller that the Alfven speed. We find that in the latter regime the heat transfer is partially suppressed, while in the former regime the effects of turbulence depend on the intensity of driving. In fact, the scale l at which the turbulent velocity is equal the Alfven velocity is a new important parameter. When the electron mean free path is larger than l, the stronger the the turbulence, the lower thermal conductivity by electrons is. The turbulent motions, however, induces their own advective heat transport, which, for the parameters of intracluster medium (ICM) provides effective heat diffusivity that exceeds the classical Spitzer value.

A. Lazarian

2006-08-02T23:59:59.000Z

286

Enhanced boiling heat transfer in horizontal test bundles  

Science Conference Proceedings (OSTI)

Two-phase flow boiling from bundles of horizontal tubes with smooth and enhanced surfaces has been investigated. Experiments were conducted in pure refrigerant R-113, pure R-11, and mixtures of R-11 and R-113 of approximately 25, 50, and 75% of R-113 by mass. Tests were conducted in two staggered tube bundles consisting of fifteen rows and five columns laid out in equilateral triangular arrays with pitch-to-diameter ratios of 1.17 and 1.5. The enhanced surfaces tested included a knurled surface (Wolverine`s Turbo-B) and a porous surface (Linde`s High Flux). Pool boiling tests were conducted for each surface so that reference values of the heat transfer coefficient could be obtained. Boiling heat transfer experiments in the tube bundles were conducted at pressures of 2 and 6 bar, heat flux values from 5 to 80 kW/m{sup 2}s, and qualities from 0% to 80%, Values of the heat transfer coefficients for the enhanced surfaces were significantly larger than for the smooth tubes and were comparable to the values obtained in pool boiling. It was found that the performance of the enhanced tubes could be predicted using the pool boiling results. The degradation in the smooth tube heat transfer coefficients obtained in fluid mixtures was found to depend on the difference between the molar concentration in the liquid and vapor.

Trewin, R.R.; Jensen, M.K.; Bergles, A.E.

1994-08-01T23:59:59.000Z

287

Combined heat and mass transfer device for improving separation process  

DOE Patents (OSTI)

A two-phase small channel heat exchange matrix simultaneously provides for heat transfer and mass transfer between the liquid and vapor phases of a multi-component mixture at a single, predetermined location within a separation column, significantly improving the thermodynamic efficiency of the separation process. The small channel heat exchange matrix is composed of a series of channels having a hydraulic diameter no greater than 5.0 millimeters for conducting a two-phase coolant. In operation, the matrix provides the liquid-vapor contacting surfaces within the separation column, such that heat and mass are transferred simultaneously between the liquid and vapor phases. The two-phase coolant allows for a uniform heat transfer coefficient to be maintained along the length of the channels and across the surface of the matrix. Preferably, a perforated, concave sheet connects each channel to an adjacent channel to facilitate the flow of the liquid and vapor phases within the column and to increase the liquid-vapor contacting surface area.

Tran, Thanh Nhon (Flossmoor, IL)

1999-01-01T23:59:59.000Z

288

Combined heat and mass transfer device for improving separation process  

DOE Patents (OSTI)

A two-phase small channel heat exchange matrix simultaneously provides for heat transfer and mass transfer between the liquid and vapor phases of a multi-component mixture at a single, predetermined location within a separation column, significantly improving the thermodynamic efficiency of the separation process. The small channel heat exchange matrix is composed of a series of channels having a hydraulic diameter no greater than 5.0 millimeters for conducting a two-phase coolant. In operation, the matrix provides the liquid-vapor contacting surfaces within the separation column, such that heat and mass are transferred simultaneously between the liquid and vapor phases. The two-phase coolant allows for a uniform heat transfer coefficient to be maintained along the length of the channels and across the surface of the matrix. Preferably, a perforated, concave sheet connects each channel to an adjacent channel to facilitate the flow of the liquid and vapor phases within the column and to increase the liquid-vapor contacting surface area. 12 figs.

Tran, T.N.

1999-08-24T23:59:59.000Z

289

Investigation of methods to transfer heat from solar liquid-heating collectors to heat storage tanks. Final report  

DOE Green Energy (OSTI)

A study was made of the methods available to transfer heat from the collector to the water storage tank in water heating systems. In counterflow heat exchangers used in double loop water heating systems, it was found to be more important to use a high water flowrate than a high heat transfer fluid flowrate. It was earlier thought to be best to have matched WC/sub p/ (mass flowrate-specific heat) products in the loops. It was shown in this study that the water WC/sub p/ product should be about twice as large as that of the heat transfer fluid. It was found that neither the heat exchanger type nor the size was very critical, so that very simple criteria were adequate in determining optimum heat exchanger size. It was found that there is a definite system size below which one should use a traced tank or a coil in a tank. Equations and optimization criteria were developed for traced tanks or tanks with coils. At present, there is no quantitative understanding of liquid to liquid (direct contact) heat exchangers, though they are clearly quite effective. Draindown systems are discussed, and several appendices are included on heat transfer and other characteristics of fluid and of equipment.

Horel, J. D.; de Winter, F.

1978-04-20T23:59:59.000Z

290

Enhanced heat transfer with metal wool filled tubes  

SciTech Connect

The Advanced Photon Source (APS) to be constructed at Argonne National Laboratory (ANL) utilizes magnetic devices which generate x-ray beams with very intense heat flux levels. The flux levels encountered can be one or two orders of magnitude higher than those commonly found in nuclear reactors or fusion devices. The beam line elements and optics on such beams pose significant challenge to the researchers and designers to keep them cooled at acceptable levels of surface temperature and/or temperature gradients. Therefore, methods and techniques achieving heat removal enhancement are constantly sought. One such technique suggested and considered is the use of conductive metal wool filled tubes where the filter is brazed to the tube walls. A comparative investigation of the conventionally achievable heat transfer coefficient h'' with water and the wall conductance of a heavy wall copper tube reveals that major resistance is on the coolant side. Therefore, there exists a significant opportunity to improve heat transfer in the tubes by enhancement of the coolant side. To this end a variety of copper wool filled tubes as well as a commercially available enhanced copper tube were subjected to laboratory tests with water and conventional heating to assess the resulting heat transfer improvement. Design improvements using enhanced cooling are discussed in terms of structural weight, controls, grazing angles, the operational reliability. 9 refs., 11 figs., 5 tabs.

Kuzay, T.M.; Collins, J.T.; Khounsary, A.M. (Argonne National Lab., IL (USA)); Morales, G. (Argonne National Lab., IL (USA) Texas Univ., El Paso, TX (USA))

1990-08-01T23:59:59.000Z

291

Trace formulae for non-equilibrium Casimir interactions, heat radiation and heat transfer for arbitrary objects  

E-Print Network (OSTI)

We present a detailed derivation of heat radiation, heat transfer and (Casimir) interactions for N arbitrary objects in the framework of fluctuational electrodynamics in thermal non-equilibrium. The results can be expressed as basis-independent trace formulae in terms of the scattering operators of the individual objects. We prove that heat radiation of a single object is positive, and that heat transfer (for two arbitrary passive objects) is from the hotter to a colder body. The heat transferred is also symmetric, exactly reversed if the two temperatures are exchanged. Introducing partial wave-expansions, we transform the results for radiation, transfer and forces into traces of matrices that can be evaluated in any basis, analogous to the equilibrium Casimir force. The method is illustrated by (re)deriving the heat radiation of a plate, a sphere and a cylinder. We analyze the radiation of a sphere for different materials, emphasizing that a simplification often employed for metallic nano-spheres is typically invalid. We derive asymptotic formulae for heat transfer and non-equilibrium interactions for the cases of a sphere in front a plate and for two spheres, extending previous results. As an example, we show that a hot nano-sphere can levitate above a plate with the repulsive non-equilibrium force overcoming gravity -- an effect that is not due to radiation pressure.

Matthias Krüger; Giuseppe Bimonte; Thorsten Emig; Mehran Kardar

2012-07-02T23:59:59.000Z

292

Enhanced heat transfer surface for cast-in-bump-covered cooling surfaces and methods of enhancing heat transfer  

DOE Patents (OSTI)

An annular turbine shroud separates a hot gas path from a cooling plenum containing a cooling medium. Bumps are cast in the surface on the cooling side of the shroud. A surface coating overlies the cooling side surface of the shroud, including the bumps, and contains cooling enhancement material. The surface area ratio of the cooling side of the shroud with the bumps and coating is in excess of a surface area ratio of the cooling side surface with bumps without the coating to afford increased heat transfer across the element relative to the heat transfer across the element without the coating.

Chiu, Rong-Shi Paul (Glenmont, NY); Hasz, Wayne Charles (Pownal, VT); Johnson, Robert Alan (Simpsonville, SC); Lee, Ching-Pang (Cincinnati, OH); Abuaf, Nesim (Lincoln City, OR)

2002-01-01T23:59:59.000Z

293

Method of measuring heat influx of a cryogenic transfer system  

DOE Patents (OSTI)

A method is provided for measuring the heat influx of a cryogenic transfer system. A gaseous phase of the cryogen used during normal operation of the system is passed through the system. The gaseous cryogen at the inlet to the system is tempered to duplicate the normal operating temperature of the system inlet. The temperature and mass flow rate of the gaseous cryogen is measured at the outlet of the system, and the heat capacity of the cryogen is determined. The heat influx of the system is then determined from known thermodynamic relationships.

Niemann, Ralph C. (Downers Grove, IL); Zelipsky, Steven A. (Tinley Park, IL); Rezmer, Ronald R. (Lisle, IL); Smelser, Peter (Bruner, MO)

1981-01-01T23:59:59.000Z

294

Numerical and experimental validation of heat and mass transfer during heat treatment of wood  

Science Conference Proceedings (OSTI)

In the current work, the three-dimensional Navier-Stokes equations along with the energy and concentration equations for the fluid coupled with the energy and mass conservation equations for the solid (wood) are solved to study the transient heat and ... Keywords: Luikov's model, conjugate problem, heat and mass transfer, high-temperature wood treatment, mathematical modeling, validation

R. Younsi; D. Kocaefe; S. Poncsak; T. Junjun

2007-05-01T23:59:59.000Z

295

Investigation of Enhanced Heat Transfer Coefficient with an Electrostatic Grid  

Science Conference Proceedings (OSTI)

Some major contributors to efficiency loss in a fossil or nuclear plant are associated with nucleation of moisture from superheated steam, formation and release of liquid films on turbine surfaces, and the flow and condensation of moist steam into the turbine exhaust and condenser. This report investigates the possible effect of an electrostatic charge on these processes and therefore on heat transfer.

2004-09-15T23:59:59.000Z

296

A mesoscopic description of radiative heat transfer at the nanoscale  

E-Print Network (OSTI)

We present a formulation of the nanoscale radiative heat transfer (RHT) using concepts of mesoscopic physics. We introduce the analog of the Sharvin conductance using the quantum of thermal conductance. The formalism provides a convenient framework to analyse the physics of RHT at the nanoscale. Finally, we propose a RHT experiment in the regime of quantized conductance.

Svend-Age Biehs; Emmanuel Rousseau; Jean-Jacques Greffet

2011-03-11T23:59:59.000Z

297

Integration of Heat Transfer, Stress, and Particle Trajectory Simulation  

Science Conference Proceedings (OSTI)

Calabazas Creek Research, Inc. developed and currently markets Beam Optics Analyzer (BOA) in the United States and abroad. BOA is a 3D, charged particle optics code that solves the electric and magnetic fields with and without the presence of particles. It includes automatic and adaptive meshing to resolve spatial scales ranging from a few millimeters to meters. It is fully integrated with CAD packages, such as SolidWorks, allowing seamless geometry updates. The code includes iterative procedures for optimization, including a fully functional, graphical user interface. Recently, time dependent, particle in cell capability was added, pushing particles synchronically under quasistatic electromagnetic fields to obtain particle bunching under RF conditions. A heat transfer solver was added during this Phase I program. Completed tasks include: (1) Added a 3D finite element heat transfer solver with adaptivity; (2) Determined the accuracy of the linear heat transfer field solver to provide the basis for development of higher order solvers in Phase II; (3) Provided more accurate and smoother power density fields; and (4) Defined the geometry using the same CAD model, while maintaining different meshes, and interfacing the power density field between the particle simulator and heat transfer solvers. These objectives were achieved using modern programming techniques and algorithms. All programming was in C++ and parallelization in OpenMP, utilizing state-of-the-art multi-core technology. Both x86 and x64 versions are supported. The GUI design and implementation used Microsoft Foundation Class.

Thuc Bui; Michael Read; Lawrence ives

2012-05-17T23:59:59.000Z

298

Heat transfer in inertial confinement fusion reactor systems  

SciTech Connect

The short time and deposition distance for the energy from inertial fusion products results in local peak power densities on the order of 10/sup 18/ watts/m/sup 3/. This paper presents an overview of the various inertial fusion reactor designs which attempt to reduce these peak power intensities and describes the heat transfer considerations for each design.

Hovingh, J.

1980-04-23T23:59:59.000Z

299

Thermodynamics of enhanced heat transfer: a model study  

E-Print Network (OSTI)

Situations where a spontaneous process of energy or matter transfer is enhanced by an external device are widespread in nature (human sweating system, enzyme catalysis, facilitated diffusion across bio-membranes, industrial heat exchangers). The thermodynamics of such processes remains however open. Here we study enhanced heat transfer by a model junction immersed between two thermal baths at different temperatures $T_h$ and $T_c$ ($T_h>T_c$). The transferred heat power is enhanced via controlling the junction by means of external time-dependent fields. Provided that the spontaneous heat flow process is optimized over the junction Hamiltonian, any enhancement of this spontaneous process does demand consumption and subsequent dissipation of work. The efficiency of enhancement is defined via the increment in the heat power divided over the amount of consumed work. We show that this efficiency is bounded from above by $T_c/(T_h-T_c)$. Formally this is identical to the Carnot bound for the efficiency of ordinary ...

Hovhannisyan, Karen; 10.1088/1742-5468/2010/06/P06010

2010-01-01T23:59:59.000Z

300

Combined heat and mass transfer device for improving separation process  

DOE Patents (OSTI)

A two-phase small channel heat exchange matrix for providing simultaneous heat transfer and mass transfer at a single, predetermined location within a separation column, whereby the thermodynamic efficiency of the separation process is significantly improved. The small channel heat exchange matrix is comprised of a series of channels having a hydraulic diameter no greater than 5.0 mm. The channels are connected to an inlet header for supplying a two-phase coolant to the channels and an outlet header for receiving the coolant horn the channels. In operation, the matrix provides the liquid-vapor contacting surfaces within a separation column, whereby liquid descends along the exterior surfaces of the cooling channels and vapor ascends between adjacent channels within the matrix. Preferably, a perforated and concave sheet connects each channel to an adjacent channel, such that liquid further descends along the concave surfaces of the sheets and the vapor further ascends through the perforations in the sheets. The size and configuration of the small channel heat exchange matrix allows the heat and mass transfer device to be positioned within the separation column, thereby allowing precise control of the local operating conditions within the column and increasing the energy efficiency of the process.

Tran, Thanh Nhon

1997-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "radiant heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Fact Sheet Radiant barriers and interior radiation control  

E-Print Network (OSTI)

the insulation, the radiant barrier will lose most of its effectiveness in reducing heating and cooling loads in central Florida. Subsequent monitoring and data analysis showed cooling energy savings of 9%, peak load with air-conditioning ductwork in the attic in the deep south (such as in Miami in Zone 1 or Austin in Zone

Oak Ridge National Laboratory

302

Deep Eutectic Salt Formulations Suitable as Advanced Heat Transfer Fluids  

Science Conference Proceedings (OSTI)

Concentrating solar power (CSP) facilities are comprised of many miles of fluid-filled pipes arranged in large grids with reflective mirrors used to capture radiation from the sun. Solar radiation heats the fluid which is used to produce steam necessary to power large electricity generation turbines. Currently, organic, oil-based fluid in the pipes has a maximum temperature threshold of 400 °C, allowing for the production of electricity at approximately 15 cents per kilowatt hour. The DOE hopes to foster the development of an advanced heat transfer fluid that can operate within higher temperature ranges. The new heat transfer fluid, when used with other advanced technologies, could significantly decrease solar electricity cost. Lower costs would make solar thermal electricity competitive with gas and coal and would offer a clean, renewable source of energy. Molten salts exhibit many desirable heat transfer qualities within the range of the project objectives. Halotechnics developed advanced heat transfer fluids (HTFs) for application in solar thermal power generation. This project focused on complex mixtures of inorganic salts that exhibited a high thermal stability, a low melting point, and other favorable characteristics. A high-throughput combinatorial research and development program was conducted in order to achieve the project objective. Over 19,000 candidate formulations were screened. The workflow developed to screen various chemical systems to discover salt formulations led to mixtures suitable for use as HTFs in both parabolic trough and heliostat CSP plants. Furthermore, salt mixtures which will not interfere with fertilizer based nitrates were discovered. In addition for use in CSP, the discovered salt mixtures can be applied to electricity storage, heat treatment of alloys and other industrial processes.

Raade, Justin; Roark, Thomas; Vaughn, John; Bradshaw, Robert

2013-07-22T23:59:59.000Z

303

Heat Transfer and Latent Heat Storage in Inorganic Molten Salts for Concentrating Solar Power Plants  

Science Conference Proceedings (OSTI)

A key technological issue facing the success of future Concentrating Solar Thermal Power (CSP) plants is creating an economical Thermal Energy Storage (TES) system. Current TES systems use either sensible heat in fluids such as oil, or molten salts, or use thermal stratification in a dual-media consisting of a solid and a heat-transfer fluid. However, utilizing the heat of fusion in inorganic molten salt mixtures in addition to sensible heat , as in a Phase change material (PCM)-based TES, can significantly increase the energy density of storage requiring less salt and smaller containers. A major issue that is preventing the commercial use of PCM-based TES is that it is difficult to discharge the latent heat stored in the PCM melt. This is because when heat is extracted, the melt solidifies onto the heat exchanger surface decreasing the heat transfer. Even a few millimeters of thickness of solid material on heat transfer surface results in a large drop in heat transfer due to the low thermal conductivity of solid PCM. Thus, to maintain the desired heat rate, the heat exchange area must be large which increases cost. This project demonstrated that the heat transfer coefficient can be increase ten-fold by using forced convection by pumping a hyper-eutectic salt mixture over specially coated heat exchanger tubes. However,only 15% of the latent heat is used against a goal of 40% resulting in a projected cost savings of only 17% against a goal of 30%. Based on the failure mode effect analysis and experience with pumping salt at near freezing point significant care must be used during operation which can increase the operating costs. Therefore, we conclude the savings are marginal to justify using this concept for PCM-TES over a two-tank TES. The report documents the specialty coatings, the composition and morphology of hypereutectic salt mixtures and the results from the experiment conducted with the active heat exchanger along with the lessons learnt during experimentation.

Mathur, Anoop [Terrafore Inc.] [Terrafore Inc.

2013-08-14T23:59:59.000Z

304

Estimation of heat transfer in oscillating annular flow using artifical neural networks  

Science Conference Proceedings (OSTI)

In this study, the prediction of heat transfer from a surface having constant heat flux subjected to oscillating annular flow is investigated using artificial neural networks (ANNs). An experimental study is carried out to estimate the heat transfer ... Keywords: Annular duct, Artificial neural network, Heat transfer, Oscillating flow

Unal Akdag; M. Aydin Komur; A. Feridun Ozguc

2009-09-01T23:59:59.000Z

305

Radiant Solar | Open Energy Information  

Open Energy Info (EERE)

Radiant Solar Radiant Solar Jump to: navigation, search Name Radiant Solar Place Secunderabad, Andhra Pradesh, India Zip 500009 Sector Solar Product Solar products company focused on lanterns, lighting systems and water heaters. Coordinates 17.46071°, 78.49298° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":17.46071,"lon":78.49298,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

306

Heat transfer and hydrodynamics analysis of a novel dimpled tube  

SciTech Connect

In the present investigation, heat transfer and hydrodynamics analysis of a new enhanced heat transfer tube with ellipsoidal dimples was carried out. The dimples are disposed to form a certain specified angle between the major axis of the ellipsoid and flow direction, and the direction of the major axis of each adjacent ellipsoidal dimple in the same cross-section is alternated. Experimental tests were carried out with heating water on the shell side with a constant flow rate, and cold air in the tube side with flow rates range from 1 to 55 m{sup 3}/h. The temperatures and pressures for the inlet and outlet of both sides were measured. The heat transfer and pressure drop of the new dimpled tube were investigated and compared with the results of a dimpled tube with spherical dimples and a conventional smooth tube. The computed results indicated that the Nusselt number for ellipsoidal dimpled tube and spherical dimpled tube are 38.6-175.1% and 34.1-158% higher than that for the smooth tube respectively. The friction factors of dimpled tube increase by 26.9-75% and 32.9-92% for ellipsoidal and spherical dimples compared with the smooth tube respectively. It was perceived that ellipsoidal dimple roughness accelerates transition to critical Reynolds numbers down to less than 1000. By integrated performance evaluation of (Nu{sub a}/Nu{sub s})/(f{sub a}/f{sub s}), a maximum of about 87% heat transfer enhancement with the same friction penalty could be achieved by optimize the dimpled tube design. (author)

Wang, Yu.; He, Ya-Ling; Lei, Yong-Gang; Zhang, Jie [State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049 (China)

2010-11-15T23:59:59.000Z

307

Analysis of a hybrid UFAD and radiant hydronic slab HVAC system  

E-Print Network (OSTI)

radiant ceiling slab. A cooling tower supplies water to pre-served by a free-cooling tower to pre-cool the buildingcoils. A two-speed cooling tower combined with a plate heat

Raftery, Paul; Lee, Kwang Ho; Webster, Thomas; Bauman, Fred

2011-01-01T23:59:59.000Z

308

Simulation of a Heat Transfer in Porous Media  

E-Print Network (OSTI)

We are motivated to model a heat transfer to a multiple layer regime and their optimization for heat energy resources. Such a problem can be modeled by a porous media with different phases (liquid and solid). The idea arose of a geothermal energy reservoir which can be used by cities, e.g. Berlin. While hot ground areas are covered to most high populated cites, the energy resources are important and a shift to use such resources are enormous. We design a model of the heat transport via the flow of water through the heterogeneous layer of the underlying earth sediments. We discuss a multiple layer model, based on mobile and immobile zones. Such numerical simulations help to economize on expensive physical experiments and obtain control mechanisms for the delicate heating process.

Juergen Geiser

2012-05-11T23:59:59.000Z

309

MODELING HEAT TRANSFER IN SPENT FUEL TRANSFER CASK NEUTRON SHIELDS – A CHALLENGING PROBLEM IN NATURAL CONVECTION  

SciTech Connect

In the United States, commercial spent nuclear fuel is typically moved from spent fuel pools to outdoor dry storage pads within a transfer cask system that provides radiation shielding to protect personnel and the surrounding environment. The transfer casks are cylindrical steel enclosures with integral gamma and neutron radiation shields. Since the transfer cask system must be passively cooled, decay heat removal from spent nuclear fuel canister is limited by the rate of heat transfer through the cask components, and natural convection from the transfer cask surface. The primary mode of heat transfer within the transfer cask system is conduction, but some cask designs incorporate a liquid neutron shield tank surrounding the transfer cask structural shell. In these systems, accurate prediction of natural convection within the neutron shield tank is an important part of assessing the overall thermal performance of the transfer cask system. The large-scale geometry of the neutron shield tank, which is typically an annulus approximately 2 meters in diameter but only 10-15 cm in thickness, and the relatively small scale velocities (typically less than 5 cm/s) represent a wide range of spatial and temporal scales that contribute to making this a challenging problem for computational fluid dynamics (CFD) modeling. Relevant experimental data at these scales are not available in the literature, but some recent modeling studies offer insights into numerical issues and solutions; however, the geometries in these studies, and for the experimental data in the literature at smaller scales, all have large annular gaps that are not prototypic of the transfer cask neutron shield. This paper proposes that there may be reliable CFD approaches to the transfer cask problem, specifically coupled steady-state solvers or unsteady simulations; however, both of these solutions take significant computational effort. Segregated (uncoupled) steady state solvers that were tested did not accurately capture the flow field and heat transfer distribution in this application. Mesh resolution, turbulence modeling, and the tradeoff between steady state and transient solutions are addressed. Because of the critical nature of this application, the need for new experiments at representative scales is clearly demonstrated.

Fort, James A.; Cuta, Judith M.; Bajwa, C.; Baglietto, E.

2010-07-18T23:59:59.000Z

310

Coupled Reactor Kinetics and Heat Transfer Model for Heat Pipe Cooled Reactors  

SciTech Connect

Heat pipes are often proposed as cooling system components for small fission reactors. SAFE-300 and STAR-C are two reactor concepts that use heat pipes as an integral part of the cooling system. Heat pipes have been used in reactors to cool components within radiation tests (Deverall, 1973); however, no reactor has been built or tested that uses heat pipes solely as the primary cooling system. Heat pipe cooled reactors will likely require the development of a test reactor to determine the main differences in operational behavior from forced cooled reactors. The purpose of this paper is to describe the results of a systems code capable of modeling the coupling between the reactor kinetics and heat pipe controlled heat transport. Heat transport in heat pipe reactors is complex and highly system dependent. Nevertheless, in general terms it relies on heat flowing from the fuel pins through the heat pipe, to the heat exchanger, and then ultimately into the power conversion system and heat sink. A system model is described that is capable of modeling coupled reactor kinetics phenomena, heat transfer dynamics within the fuel pins, and the transient behavior of heat pipes (including the melting of the working fluid). The paper focuses primarily on the coupling effects caused by reactor feedback and compares the observations with forced cooled reactors. A number of reactor startup transients have been modeled, and issues such as power peaking, and power-to-flow mismatches, and loading transients were examined, including the possibility of heat flow from the heat exchanger back into the reactor. This system model is envisioned as a tool to be used for screening various heat pipe cooled reactor concepts, for designing and developing test facility requirements, for use in safety evaluations, and for developing test criteria for in-pile and out-of-pile test facilities.

WRIGHT,STEVEN A.; HOUTS,MICHAEL

2000-11-22T23:59:59.000Z

311

Analysis of annual thermal and moisture performance of radiant barrier systems  

Science Conference Proceedings (OSTI)

This report summarizes a project to model the annual thermal and moisture performance of radiant barrier systems installed in residential attics. A previously developed model for the thermal performance of attics with radiant barriers was modified to allow estimates of moisture condensation on the underside of radiant barriers that are laid directly on top of existing attic insulation. The model was partially validated by comparing its predictions of ceiling heat flows and moisture condensation with data and visual observations made during a field experiment with full-size houses near Knoxville, Tennessee. Since the model predictions were found to be in reasonable agreement with the experimental data, the models were used to estimate annual energy savings and moisture accumulation rates for a wide variety of climatic conditions. The models results have been used to identify locations where radiant barriers are cost effective and also where radiant barriers have potential for causing moisture problems. 58 refs., 20 figs., 32 tabs.

Wilkes, K.E.

1991-04-01T23:59:59.000Z

312

Thermal performance of clean horizontal radiant barriers under winter conditions: Laboratory measurements and mathematical modeling  

Science Conference Proceedings (OSTI)

Several field experiments have been performed on attic radiant barriers under winter conditions; however, most of them have been confined to the fairly mild climates of Florida, Oklahoma, and Tennessee. Only one field experiment in a very cold climate (Canada) has been performed. In addition, no previous laboratory experiments under winter conditions have been performed on an attic both with and without a radiant barrier. This paper presents the results of laboratory measurements of the thermal performance of clean horizontal radiant barriers in a simulated residential attic module under nighttime or low solar gain daytime winter conditions. Comparing tests under the same conditions with and without a radiant barrier shows that the addition of a clean horizontal radiant barrier to insulation at the R-22 to R-25 level decreases the ceiling heat flow by 6 to 8%. The experimental results were found to be in very good agreement with predictions made with a mathematical model for the thermal performance of attics.

Wilkes, K.E.; Childs, P.W.

1992-01-01T23:59:59.000Z

313

Analysis of annual thermal and moisture performance of radiant barrier systems  

Science Conference Proceedings (OSTI)

This report summarizes a project to model the annual thermal and moisture performance of radiant barrier systems installed in residential attics. A previously developed model for the thermal performance of attics with radiant barriers was modified to allow estimates of moisture condensation on the underside of radiant barriers that are laid directly on top of existing attic insulation. The model was partially validated by comparing its predictions of ceiling heat flows and moisture condensation with data and visual observations made during a field experiment with full-size houses near Knoxville, Tennessee. Since the model predictions were found to be in reasonable agreement with the experimental data, the models were used to estimate annual energy savings and moisture accumulation rates for a wide variety of climatic conditions. The model results have been used to identify locations where radiant barriers are cost effective and also where radiant barriers have potential for causing moisture problems. 58 refs., 20 figs., 32 tabs.

Wilkes, K.E. (Oak Ridge National Lab., TN (United States))

1991-08-01T23:59:59.000Z

314

Thermal performance of clean horizontal radiant barriers under winter conditions: Laboratory measurements and mathematical modeling  

Science Conference Proceedings (OSTI)

Several field experiments have been performed on attic radiant barriers under winter conditions; however, most of them have been confined to the fairly mild climates of Florida, Oklahoma, and Tennessee. Only one field experiment in a very cold climate (Canada) has been performed. In addition, no previous laboratory experiments under winter conditions have been performed on an attic both with and without a radiant barrier. This paper presents the results of laboratory measurements of the thermal performance of clean horizontal radiant barriers in a simulated residential attic module under nighttime or low solar gain daytime winter conditions. Comparing tests under the same conditions with and without a radiant barrier shows that the addition of a clean horizontal radiant barrier to insulation at the R-22 to R-25 level decreases the ceiling heat flow by 6 to 8%. The experimental results were found to be in very good agreement with predictions made with a mathematical model for the thermal performance of attics.

Wilkes, K.E.; Childs, P.W.

1992-08-01T23:59:59.000Z

315

Solidification Heat Transfer Analysis of AZ91D Cast Strip by Using a ...  

Science Conference Proceedings (OSTI)

The heat transfer coefficient between the molten magnesium ally and copper roll is important to cast magnesium strip. In the present study investigate the heat ...

316

Exploring the Limits of Boiling and Evaporative Heat Transfer Using Micro/Nano Structures.  

E-Print Network (OSTI)

??This dissertation presents a study exploring the limits of phase-change heat transfer with the aim of enhancing critical heat flux (CHF) in pool boiling and… (more)

Lu, Ming-Chang

2010-01-01T23:59:59.000Z

317

High Operating Temperature Liquid Metal Heat Transfer Fluids  

NLE Websites -- All DOE Office Websites (Extended Search)

Liquid Metal Liquid Metal Heat Transfer Fluids UCLA, UCB, Yale DE-EE0005941 | April 15, 2013 | Ju 1.1 Thermochemistry modeling * Continue CALPHAD based calculations to search for optimal ternary alloy compositions. * Initiate development of liquid density models. 1.2 Combinatorial synthesis and characterization * Pipe-Liquid interaction of compositional library * More alloys, alloy additions and effect on liquidus temperatures * Iteratively optimize the compositions. 1.3 Corrosion characterization and mitigation * Tune static corrosion testing systems for testing over an extended period of time. * Perform analysis of the micro mechanical testing on the oxide layers. 1.4 Heat transfer characterization and modeling * Complete the construction of the flow loop and perform experiments to measure

318

Advanced Heat Transfer Fluids for Concentrated Solar Power (CSP)  

NLE Websites -- All DOE Office Websites (Extended Search)

Science Science Computing, Environment & Life Sciences Energy Engineering & Systems Analysis Photon Sciences Physical Sciences & Engineering Energy Frontier Research Centers Science Highlights Postdoctoral Researchers Advanced Heat Transfer Fluids for Concentrated Solar Power (CSP) Applications November 1, 2011 Tweet EmailPrint The current levelized cost of energy (LCOE) from concentrated solar power (CSP) is ~ $0.11/kWh. The U.S. Department of Energy has set goals to reduce this cost to ~$0.07/kWh with 6 hours of storage by 2015 and to ~$0.05/kWh with 16 hours of storage by 2020. To help meet these goals, scientists at Argonne National Laboratory are working to improve the overall CSP plant efficiency by enhancing the thermophysical properties of heat transfer

319

Combustion Simulations [Heat Transfer and Fluid Mechanics] - Nuclear  

NLE Websites -- All DOE Office Websites (Extended Search)

Combustion Simulations Combustion Simulations Capabilities Engineering Computation and Design Engineering and Structural Mechanics Systems/Component Design, Engineering and Drafting Heat Transfer and Fluid Mechanics Overview Thermal Hydraulic Optimization of Nuclear Systems Underhood Thermal Management Combustion Simulations Advanced Model and Methodology Development Multi-physics Reactor Performance and Safety Simulations Other Capabilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Heat Transfer and Fluid Mechanics Bookmark and Share Combustion Simulations Density Distribution of Spray in Near-Injector Region Density Distribution of Spray in Near-Injector Region. Click on image to view larger image. Development of computer models based on Front-Tracking and

320

Heat transfer research and power cycle transient modeling  

DOE Green Energy (OSTI)

Fine axial flutes enhance heat transfer in vertical shell-and-tube exchangers with water inside the tubes and ammonia evaporating or condensing in layer flow on the shell side. Single-tube experiments with R-11 and ammonia indicate local shell-side coefficients 3 to 5 times those for corresponding smooth tubes. Single-tube experiments with water indicate that at moderate velocities the tube-side coefficients are enhanced by a factor equal to the ratio of fluted-to-smooth surface areas while the fluid friction is similarly increased. The experimental data are transformed into mean individual coefficients for ammonia and water. Overall coefficients for a particular case are presented to illustrate the efficacy of enhancement by flutes on one or both sides of the heat transfer surface. Means are described for using emerging data to predict the static and dynamic behavior of the power cycle and the interactions of components throughout the complete power plant.

Rothfus, R.R.; Neuman, C.P.

1977-03-23T23:59:59.000Z

Note: This page contains sample records for the topic "radiant heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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321

Optical techniques for fluid flow and heat transfer  

Science Conference Proceedings (OSTI)

A review is presented of optical measuring techniques employed in momentum heat and mass transfer studies. A classification is given of those techniques that are nowadays widely employed in studies to advance the understanding of transport phenomena in fluids. Techniques that employ effects caused by fluid molecules are briefly treated, and examples of measurements are given to demonstrate the kind of information that can be obtained by these techniques. Optical techniques using tracers to obtain transport information are summarized, and laser-Doppler anemometry and its application to fluid flow studies are emphasized. Applications of this technique in single-phase and two-phase flows are given that demonstrate its potential in experimental fluid mechanics and convective heat transfer studies. 63 refs.

Durst, F. (Erlangen-Nuernberg Universitaet, Erlangen (Germany, F.R.))

1990-01-01T23:59:59.000Z

322

Heat Transfer Modeling of Dry Spent Nuclear Fuel Storage Facilities  

Science Conference Proceedings (OSTI)

The present work was undertaken to provide heat transfer model that accurately predicts the thermal performance of dry spent nuclear fuel storage facilities. One of the storage configurations being considered for DOE Aluminum-clad Spent Nuclear Fuel (Al-SNF), such as the Material and Testing Reactor (MTR) fuel, is in a dry storage facility. To support design studies of storage options a computational and experimental program has been conducted at the Savannah River Site (SRS). The main objective is to develop heat transfer models including natural convection effects internal to an interim dry storage canister and to geological codisposal Waste Package (WP). Calculated temperatures will be used to demonstrate engineering viability of a dry storage option in enclosed interim storage and geological repository WP and to assess the chemical and physical behaviors of the Al-SNF in the dry storage facilities. The current paper describes the modeling approaches and presents the computational results along with the experimental data.

Lee, S.Y.

1999-01-13T23:59:59.000Z

323

Rocket-borne, low gravity cryogenic heat transfer experiment  

SciTech Connect

From AIAA/NSA/ASTM/IES 7th space simulation conference; Los Angeles, Calif11nia, USA (12 Nov 1973). In order to obtain steady state data on nucleate boiling heat transfer to liquid helium in a nearly zero gravity environment a rocket-borne experiment was designed, built and successfully flown. A description of the apparatus and flight is presented along with preliminary results. (auth)

Williamson, K.D. Jr.; Edeskuty, F.J.; Taylor, J.F.

1974-04-30T23:59:59.000Z

324

Heat transfer investigations in a slurry bubble column  

SciTech Connect

Slurry bubble columns, for use in Fisher-Tropsch synthesis, have been investigated. Two bubble columns (0.108 and 0.305 m internal diameter) were set up and experiments were conducted to determine gas holdup and heat transfer coefficients. These columns were equipped with either single heat transfer probes of different diameters, or bundles of five-, seven- or thirty-seven tubes. The experiments were conducted for two- and three-phase systems; employing for gas phase: air and nitrogen, liquid phase: water and Therminol-66, and solid phase: red iron oxide (1.02, 1.70 and 2.38 {mu}m), glass beads (50.0, 90.0, 119.0 and 143.3 {mu}m), silica sand (65 {mu}), and magnetite (28.0, 35.7, 46.0, 58.0, 69.0, 90.5, 115.5, and 137.5 {mu}m). The column temperature was varied between 298--523 K, gas velocity between 0--40 cm/s, and solids concentration between 0--50 weight percent. The holdup and heat transfer data as a function of operating and system parameters were employed to assess the available correlations and semitheoretical models, and to develop new correlations. Information concerning the design and scale-up of larger units is presented. Specific research work that need to be undertaken to understand the phenomena of heat transfer and gas holdup is outlined so that efficient gas conversion and catalyst usage may be accomplished in slurry bubble columns. 130 refs., 177 figs., 54 tabs.

Saxena, S.C.; Rao, N.S.; Vadivel, R.; Shrivastav, S.; Saxena, A.C.; Patel, B.B.; Thimmapuram, P.R.; Kagzi, M.Y.; Khan, I.A.; Verma, A.K.

1991-02-01T23:59:59.000Z

325

Nonaqueous purification of mixed nitrate heat transfer media  

DOE Patents (OSTI)

A nonaqueous, in-line method for removing carbonate and hydroxide contamination from a molten mixed sodium nitrate/potassium nitrate heat transfer salt. The method comprises dissolving a stoichiometric quantity of anhydrous Ca(NO.sub.3).sub.2 in the melt whereby an insoluble CaCO.sub.3 and Ca(OH).sub.2 precipitate is formed. The precipitate can be removed by settling, filtration or floatation techniques.

Fiorucci, Louis C. (Hamden, CT); Morgan, Michael J. (Guilford, CT)

1983-12-20T23:59:59.000Z

326

Energy measurements of attic radiant barriers installed in single-family houses  

Science Conference Proceedings (OSTI)

Testing was conducted by the Oak Ridge National Laboratory to determine the energy savings attributable to radiant barriers installed in attics of unoccupied single-family houses. Three levels of fiberglass attic insulation (R-11 ,R-19, and R-30) were tested with two types of barrier installation (horizontal and truss). The results showed that horizontally installed radiant barriers were more effective than truss barriers in reducing heating and cooling loads. Measured cooling load reductions ranged form 0 to 22% (compared to same attic insulation insulation R-value with no radiant barrier) and heating load changes from /plus/4% to /minus/10% were measured (compared to same attic insulation R-value with no radiant barrier). Radiant barriers appeared to decrease the heating and cooling loads more when lesser amounts of insulation (R-11 and R-19) were present in an attic. Minimal changes were measured when R-30 was present in an attic. Long-term effects of dust on the performance of radiant barriers as well as the effects of moisture condensing on the surface of a radiant barrier during cold winter temperatures remain unanswered.

Levins, W.P.; Karnitz, M.A.

1988-07-01T23:59:59.000Z

327

Simulated Attic Radiant Barrier Performance  

Science Conference Proceedings (OSTI)

A recent EPRI evaluation determined that attic radiant barriers installed under roof decks are increasingly effective in reducing cooling energy use as insolation increases and ceiling insulation thickness decreases. A savings worksheet included in this report allows rapid estimation of these energy cost impacts.

1991-03-29T23:59:59.000Z

328

Situ soil sampling probe system with heated transfer line  

DOE Patents (OSTI)

The present invention is directed both to an improved in situ penetrometer probe and to a heated, flexible transfer line. The line and probe may be implemented together in a penetrometer system in which the transfer line is used to connect the probe to a collector/analyzer at the surface. The probe comprises a heater that controls a temperature of a geologic medium surrounding the probe. At least one carrier gas port and vapor collection port are located on an external side wall of the probe. The carrier gas port provides a carrier gas into the geologic medium, and the collection port captures vapors from the geologic medium for analysis. In the transfer line, a flexible collection line that conveys a collected fluid, i.e., vapor, sample to a collector/analyzer. A flexible carrier gas line conveys a carrier gas to facilitate the collection of the sample. A system heating the collection line is also provided. Preferably the collection line is electrically conductive so that an electrical power source can generate a current through it so that the internal resistance generates heat.

Robbat, Jr., Albert (Andover, MA)

2002-01-01T23:59:59.000Z

329

Simulation of heat transfer in the unsaturated zone  

SciTech Connect

Heat transfer can play an important role in fluid flow near the emplacement site of high-level nuclear waste. The effects on far- field flow can be important in understanding net moisture fluxes above the repository zone. The convection in the unsaturated zone at the Yucca Mountain site was responsible for this movement. If this is so, then the convection could provide a mechanism for drying the rock above the repository zone and thus provide a buffer for heavy rainfall events. In addition, the convection would increase the movement of gaseous radionuclides such as {sup 14}CO{sub 2}, tritiated water vapor, and {sup 129}I (Weeks, 1987). Because of the complexity of the problem, numerical models were required to calculate gas flow and vapor transport at the site. Kipp previously modeled this problem using the code HST3D. This code represents the flow of a single-phase fluid with both heat- and mass-transfer effects included. Water density and partial pressure effects are accounted for by the virtual temperature method. In this paper, the problem was simulated using the code FEHMN, a finite-element heat- and mass-transfer code being developed for the Yucca Mountain Project. The work described in this paper was done in preparation of the upcoming problem to be formulated for the Performance Assessment Calculation Exercise. 5 refs., 9 figs., 1 tab.

Zyvoloski, G.

1990-02-01T23:59:59.000Z

330

Experimental study of mixed convection heat transfer in vertical helically coiled tube heat exchangers  

Science Conference Proceedings (OSTI)

In this study the mixed convection heat transfer in a coil-in-shell heat exchanger for various Reynolds numbers, various tube-to-coil diameter ratios and different dimensionless coil pitch was experimentally investigated. The experiments were conducted for both laminar and turbulent flow inside coil. Effects of coil pitch and tube diameters on shell-side heat transfer coefficient of the heat exchanger were studied. Different characteristic lengths were used in various Nusselt number calculations to determine which length best fits the data and several equations were proposed. The particular difference in this study in comparison with the other similar studies was the boundary conditions for the helical coils. The results indicate that the equivalent diameter of shell is the best characteristic length. (author)

Ghorbani, N. [School of Mechanical Engineering, University of Leeds, Leeds, England (United Kingdom); Taherian, H. [Department of Engineering Technology and Industrial Distribution, Texas A and M University, College Station, TX (United States); Gorji, M. [Department of Mechanical Engineering, Babol Noushirvani University of Technology, Babol (Iran); Mirgolbabaei, H. [Department of Mechanical Engineering, Islamic Azad University, Jouybar branch, Jouybar (Iran)

2010-10-15T23:59:59.000Z

331

SunShot Initiative: Advanced Heat Transfer Fluids and Novel Thermal...  

NLE Websites -- All DOE Office Websites (Extended Search)

Advanced Heat Transfer Fluids and Novel Thermal Storage Concepts for CSP Generation to someone by E-mail Share SunShot Initiative: Advanced Heat Transfer Fluids and Novel Thermal...

332

Heat transfer during film condensation of potassium vapor on a horizontal plate  

E-Print Network (OSTI)

The object of the investigation is to analyze the following two features of heat transfer during condensation of potassium vapor: a. Heat transfer during film condensation of a pure saturated potassium vapor on a horizontal ...

Meyrial, Paul M.

1968-01-01T23:59:59.000Z

333

Heat transfer rates for filmwise, dropwise, and superhydrophobic condensation on silicon substrates  

E-Print Network (OSTI)

Condensation, a two-phase heat transfer processes, is commonly utilized in industrial systems. Condensation heat transfer can be optimized by using surfaces in which dropwise condensation (DWC) occurs, and even further ...

Hery, Travis M

2011-01-01T23:59:59.000Z

334

Scalable photon monte carlo algorithms and software for the solution of radiative heat transfer problems  

Science Conference Proceedings (OSTI)

Radiative heat transfer plays a central role in many combustion and engineering applications. Because of its highly nonlinear and nonlocal nature, the computational cost can be extremely high to model radiative heat transfer effects accurately. In this ...

Ivana Veljkovic; Paul E. Plassmann

2005-09-01T23:59:59.000Z

335

HEAT TRANSFER ANALYSIS FOR NUCLEAR WASTE SOLIDIFICATION CONTAINER  

SciTech Connect

The Nuclear Nonproliferation Programs Design Authority is in the design stage of the Waste Solidification Building (WSB) for the treatment and solidification of the radioactive liquid waste streams generated by the Pit Disassembly and Conversion Facility (PDCF) and Mixed Oxide (MOX) Fuel Fabrication Facility (MFFF). The waste streams will be mixed with a cementitious dry mix in a 55-gallon waste container. Savannah River National Laboratory (SRNL) has been performing the testing and evaluations to support technical decisions for the WSB. Engineering Modeling & Simulation Group was requested to evaluate the thermal performance of the 55-gallon drum containing hydration heat source associated with the current baseline cement waste form. A transient axi-symmetric heat transfer model for the drum partially filled with waste form cement has been developed and heat transfer calculations performed for the baseline design configurations. For this case, 65 percent of the drum volume was assumed to be filled with the waste form, which has transient hydration heat source, as one of the baseline conditions. A series of modeling calculations has been performed using a computational heat transfer approach. The baseline modeling results show that the time to reach the maximum temperature of the 65 percent filled drum is about 32 hours when a 43 C initial cement temperature is assumed to be cooled by natural convection with 27 C external air. In addition, the results computed by the present model were compared with analytical solutions. The modeling results will be benchmarked against the prototypic test results. The verified model will be used for the evaluation of the thermal performance for the WSB drum. Detailed results and the cases considered in the calculations will be discussed here.

Lee, S.

2009-06-01T23:59:59.000Z

336

Measurements and Predictions of the Heat Transfer at the Tube-Fin Junction for Louvered Fin Heat Exchangers  

E-Print Network (OSTI)

to the International Journal of Compact Heat Exchangers, May 2003 #12;2 Measurements and Predictions of the Heat Transfer at the Tube-Fin Junction for Louvered Fin Heat Exchangers Abstract The dominant thermal resistance for most compact heat exchangers occurs on the air side and thus a detailed understanding of air side heat

Thole, Karen A.

337

Heat Transfer Applications for the Stimulated Reservoir Volume  

E-Print Network (OSTI)

Multistage hydraulic fracturing of horizontal wells continues to be a major technological tool in the oil and gas industry. Creation of multiple transverse fractures in shale gas has enabled production from very low permeability. The strategy entails the development of a Stimulated Reservoir Volume (SRV), defined as the volume of reservoir, which is effectively stimulated to increase the well performance. An ideal model for a shale gas SRV is a rectangle of length equal to horizontal well length and width equal to twice the half length of the created hydraulic fractures. This project focused on using the Multistage Transverse Fractured Horizontal Wells (MTFHW) for two novel applications. The first application considers using the SRV of a shale gas well, after the gas production rate drops below the economic limit, for low grade geothermal heat extraction. Cold water is pumped into the fracture network through one horizontal well drilled at the fracture tips. Heat is transferred to the water through the fracture surface. The hot water is then recovered through a second horizontal well drilled at the other end of the fracture network. The basis of this concept is to use the already created stimulated reservoir volume for heat transfer purposes. This technique was applied to the SRV of Haynesville Shale and the results were discussed in light of the economics of the project. For the second application, we considered the use of a similarly created SRV for producing hydrocarbon products from oil shale. Thermal decomposition of kerogen to oil and gas requires heating the oil shale to 700 degrees F. High quality saturated steam generated using a small scale nuclear plant was used for heating the formation to the necessary temperature. Analytical and numerical models are developed for modeling heat transfer in a single fracture unit of MTFHW. These models suggest that successful reuse of Haynesville Shale gas production wells for low grade geothermal heat extraction and the project appears feasible both technically and economically. The economics of the project is greatly aided by eliminating well drilling and completion costs. The models also demonstrate the success of using MTFHW array for heating oil shale using SMR technology.

Thoram, Srikanth

2011-08-01T23:59:59.000Z

338

Modeling of Heat and Mass Transfer in Fusion Welding  

Science Conference Proceedings (OSTI)

In fusion welding, parts are joined together by melting and subsequent solidification. Although this principle is simple, complex transport phenomena take place during fusion welding, and they determine the final weld quality and performance. The heat and mass transfer in the weld pool directly affect the size and shape of the pool, the solidification microstructure, the formation of weld defects such as porosity and humping, and the temperature distribution in the fusion zone and heat-affected zone (HAZ). Furthermore, the temperature evolution affects the kinetics and extent of various solid-state phase transformations, which in turn determine the final weld microstructure and mechanical properties. The formation of residual stresses and distortion originates from the thermal expansion and contraction during welding heating and cooling, respectively.

Zhang, Wei [ORNL

2011-01-01T23:59:59.000Z

339

A composite grid solver for conjugate heat transfer in fluid-structure systems  

Science Conference Proceedings (OSTI)

We describe a numerical method for modeling temperature-dependent fluid flow coupled to heat transfer in solids. This approach to conjugate heat transfer can be used to compute transient and steady state solutions to a wide range of fluid-solid systems ... Keywords: Conjugate heat transfer, Incompressible flow, Multi-domain solvers, Numerical methods, Overlapping grids

William D. Henshaw; Kyle K. Chand

2009-06-01T23:59:59.000Z

340

An experimental investigation of convection heat transfer to supercritical carbon dioxide in miniature tubes  

E-Print Network (OSTI)

-year research program in heat transfer and viscoelastic fluid flows, after working for some time in industry of All Sciences), Fluid Mechanics, Heat Transfer and related fluid-thermal-energy sciences; with emphases Press series Advances in Heat Transfer, Volume 19, and "Viscosity" in CRC Press' Measurement

Zhao, Tianshou

Note: This page contains sample records for the topic "radiant heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Numerical investigation of heat transfer enhancement by carbon nano fibers deposited on a flat plate  

Science Conference Proceedings (OSTI)

Numerical simulations of flow and heat transfer have been performed for flow over a plate surface covered with carbon nano fibers (CNFs). The CNFs influence on fluid flow and heat transfer has been investigated. Firstly, a stochastic model for CNFs deposition ... Keywords: Carbon nano fibers, Heat transfer, Lattice Boltzmann method

Nikola Pelevic; Theo Van Der Meer

2013-03-01T23:59:59.000Z

342

Molten salt as a heat transfer fluid for heating a subsurface formation  

DOE Patents (OSTI)

A heating system for a subsurface formation includes a conduit located in an opening in the subsurface formation. An insulated conductor is located in the conduit. A material is in the conduit between a portion of the insulated conductor and a portion of the conduit. The material may be a salt. The material is a fluid at operating temperature of the heating system. Heat transfers from the insulated conductor to the fluid, from the fluid to the conduit, and from the conduit to the subsurface formation.

Nguyen, Scott Vinh (Houston, TX); Vinegar, Harold J. (Bellaire, TX)

2010-11-16T23:59:59.000Z

343

Combined Heat and Power ecopower micro CHP  

Science Conference Proceedings (OSTI)

... (Grandkids) ? Full in-floor radiant heating system in the house ? Geothermal system as backup. ? In 20 months of ecopower ...

2012-10-07T23:59:59.000Z

344

Simulation of Static Flying Attitudes with Different Heat Transfer Models for a Flying-Height Control Slider with Thermal Protrusion  

E-Print Network (OSTI)

Zhang, S. , Bogy, D.B. : A heat transfer model for thermal ?A phenomenological heat transfer model for the molecular gasWong, C.H. : A generalized heat transfer model for thin ?lm

Chen, Du; Bogy, David B.

2010-01-01T23:59:59.000Z

345

Numerical investigation of transient heat and mass transfer in a parallel-flow liquid-desiccant absorber  

E-Print Network (OSTI)

model for heat and mass transfer processes in internallyof coupled heat and mass transfer processes in liquidHeat and mass transfer in liquid des- iccant air-conditioning process

Diaz, Gerardo

2010-01-01T23:59:59.000Z

346

A Mountain-Scale Thermal Hydrologic Model for Simulating Fluid Flow and Heat Transfer in Unsaturated Fractured Rock  

E-Print Network (OSTI)

fluid flow and heat-transfer processes. The physicalcoupled fluid-flow and heat-transfer processes has proven toin which flow and heat transfer processes along drifts are

Wu, Yu-Shu; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, Gudmundur S.

2005-01-01T23:59:59.000Z

347

Modeling the Heating of Biological Tissue based on the Hyperbolic Heat Transfer Equation  

E-Print Network (OSTI)

In modern surgery, a multitude of minimally intrusive operational techniques are used which are based on the punctual heating of target zones of human tissue via laser or radio-frequency currents. Traditionally, these processes are modeled by the bioheat equation introduced by Pennes, who considers Fourier's theory of heat conduction. We present an alternative and more realistic model established by the hyperbolic equation of heat transfer. To demonstrate some features and advantages of our proposed method, we apply the obtained results to different types of tissue heating with high energy fluxes, in particular radiofrequency heating and pulsed laser treatment of the cornea to correct refractive errors. Hopefully, the results of our approach help to refine surgical interventions in this novel field of medical treatment.

Tung, M M; Molina, J A Lopez; Rivera, M J; Berjano, E J

2008-01-01T23:59:59.000Z

348

The multiple absorption coefficient zonal method (MACZM), an efficient computational approach for the analysis of radiative heat transfer in multidimensional inhomogeneous nongray media  

E-Print Network (OSTI)

of Radiative Heat Transfer, the P-3 Approximation”, AIAAMedia”, Journal of Heat Transfer, Vol. 109, No. 3 (1987),Media”, Numerical Heat Transfer, Part B, Fundamentals, Vol.

Yuen, W W

2006-01-01T23:59:59.000Z

349

Determination of a time-dependent heat transfer coefficient from non-standard boundary measurements  

Science Conference Proceedings (OSTI)

In this paper the determination of the time-dependent heat transfer coefficient in one-dimensional transient heat conduction from a non-standard boundary measurement is investigated. For this inverse nonlinear ill-posed problem the uniqueness of the ... Keywords: Boundary element method, Heat conduction, Heat transfer coefficient, Inverse problem

T. T. M. Onyango; D. B. Ingham; D. Lesnic; M. Slodi?ka

2009-01-01T23:59:59.000Z

350

Heat transfer mechanism with thin filaments including ceramic high temperature heat exchanger  

DOE Patents (OSTI)

A radiative heat transfer mechanism in a furnace having burners through which pulverized coal and air are burned producing combustion gases and contaminants. A plurality of elongated conduits are positioned inside the furnace proximate to the burners generally parallel to the flow of combustion gases in the furnace. A plurality of thin filaments are inside each of the elongated hollow conduits, the filaments having diameters in the range of from about 1 micrometer to about 1,000 micrometers and having an infrared radiation cross-section sufficient to cause the filaments to heat upon exposure to infrared radiation. Blower mechanism is associated with the elongated conduits for limiting the amount of soot and ash which deposit on the conduits to preserve the radiative and convective transfer of heat energy from the combustion gases to the conduits.

Im, Kwan H. (Naperville, IL); Ahluwalia, Rajesh K. (Burr Ridge, IL)

1994-01-01T23:59:59.000Z

351

Heat transfer mechanism with thin filaments including ceramic high temperature heat exchanger  

DOE Patents (OSTI)

A radiative heat transfer mechanism in a furnace is described having burners through which pulverized coal and air are burned producing combustion gases and contaminants. A plurality of elongated conduits are positioned inside the furnace proximate to the burners generally parallel to the flow of combustion gases in the furnace. A plurality of thin filaments are inside each of the elongated hollow conduits, the filaments having diameters in the range of from about 1 micrometer to about 1,000 micrometers and having an infrared radiation cross-section sufficient to cause the filaments to heat upon exposure to infrared radiation. Blower mechanism is associated with the elongated conduits for limiting the amount of soot and ash which deposit on the conduits to preserve the radiative and convective transfer of heat energy from the combustion gases to the conduits. 7 figs.

Im, K.H.; Ahluwalia, R.K.

1994-10-18T23:59:59.000Z

352

Effect of microfouling on heat-transfer efficiency  

DOE Green Energy (OSTI)

Field experiments, performed at Keahole Point, Hawaii and in the Gulf of Mexico, were designed to determine the relationship between decreased heat transfer efficiency and the accumulation of corrosion and/or biofouling films on heat exchanger surfaces. The sample tubes were maintained under conditions simulating those of an Ocean Thermal Energy Conversion (OTEC) system and data from the two sites have been compared. Seawater flowed through 2.54 (internal diameter) metal tubes at approximately 1.8m sec/sup -1/. Four types of tubes were used: 5052 Aluminum (A1), Grade 2 titanium (Ti), 90-10 copper-nickel (Cu-Ni) and Allegheny-Ludlum 6X stainless ssteel (SS). All surfaces were colonized by microorganisms, though colonization of the Cu-Ni surface was initially retarded. Total film weight was greatest for the Al and Cu-Ni surfaces which were characterized by corrosion as well as microbial fouling. The total organic carbon: total nitrogen ratios of the fouling films from Ti, Al, SS and Cu-Ni, 4.2, 4.0, 4.8 and 7.9 respectively, remained constant throughout the experiment. The degradation of heat transfer efficiency due to the formation of fouling layers on Ti and SS is neither linear nor a simple exponential function. A microfouling model is proposed for corrosion-resistant surfaces that is consistent with field observations.

Little, B.; Berger, L.R.

1980-01-01T23:59:59.000Z

353

NUMERICAL SIMULATION OF HEAT TRANSFER AND PRESSURE DROP IN PLATE HEAT EXCHANGERS USING FLUENT AS CFD TOOL.  

E-Print Network (OSTI)

??Corrugated walls are commonly used as passive devices for heat and mass transfer enhancement, being most effective in applications operated at transitional and turbulent Reynolds… (more)

EGEREGOR, DAFE

2008-01-01T23:59:59.000Z

354

The effect of periodic unsteady wakes on boundary layer transition and heat transfer on a curved plate.  

E-Print Network (OSTI)

??The effect of unsteady periodic wakes on heat transfer and boundary layer transition was investigated on a constant curvature heat transfer curved plate in a… (more)

Wright, Lance Cole

2012-01-01T23:59:59.000Z

355

Radiant Energy | Open Energy Information  

Open Energy Info (EERE)

Energy Energy Jump to: navigation, search Name Radiant Energy Place Pleasanton, California Zip 94566 Sector Geothermal energy, Hydro, Solar Product Radiant is an independent energy producer which develops and owns solar, geothermal, and hydroelectric generating assets. Coordinates 28.967394°, -98.478862° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":28.967394,"lon":-98.478862,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

356

Radiant Apparatus | Open Energy Information  

Open Energy Info (EERE)

Apparatus Apparatus Jump to: navigation, search Name Radiant Apparatus Place Fairfax, Virginia Zip 22038-3333 Sector Solar Product Radiant Apparatus develops multi-functional, portable solar energy-harnessing systems, as well as potable water systems and emergency shelters. Coordinates 38.841574°, -77.308132° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":38.841574,"lon":-77.308132,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

357

Heat Transfer and Reconnection Diffusion in Turbulent Magnetized Plasmas  

E-Print Network (OSTI)

It is well known that magnetic fields constrain motions of charged particles, impeding the diffusion of charged particles perpendicular to magnetic field direction. This modification of transport processes is of vital importance for a wide variety of astrophysical processes including cosmic ray transport, transfer of heavy elements in the interstellar medium, star formation etc. Dealing with these processes one should keep in mind that in realistic astrophysical conditions magnetized fluids are turbulent. In this review we single out a single transport process, namely, heat transfer and consider how it occurs in the presence of the magnetized turbulence. We show that the ability of magnetic field lines to constantly change topology and connectivity is at the heart of the correct description of the 3D magnetic field stochasticity in turbulent fluids. This ability is ensured by fast magnetic reconnection in turbulent fluids and puts forward the concept of reconnection diffusion at the core of the physical pictu...

Lazarian, A

2011-01-01T23:59:59.000Z

358

Low-melting point inorganic nitrate salt heat transfer fluid  

DOE Patents (OSTI)

A low-melting point, heat transfer fluid made of a mixture of four inorganic nitrate salts: 9-18 wt % NaNO.sub.3, 40-52 wt % KNO.sub.3, 13-21 wt % LiNO.sub.3, and 20-27 wt % Ca(NO.sub.3).sub.2. These compositions can have liquidus temperatures less than 100 C; thermal stability limits greater than 500 C; and viscosity in the range of 5-6 cP at 300 C; and 2-3 cP at 400 C.

Bradshaw, Robert W. (Livermore, CA); Brosseau, Douglas A. (Albuquerque, NM)

2009-09-15T23:59:59.000Z

359

Near-field radiative heat transfer for structured surfaces  

E-Print Network (OSTI)

We apply an analytical approach for determining the near-field radiative heat transfer between a metallic nanosphere and a planar semi-infinite medium with some given surface structure. This approach is based on a perturbative expansion, and evaluated to first order in the surface profile. With the help of numerical results obtained for some simple model geometries we discuss typical signatures that should be obtainable with a near-field scanning thermal microscope operated in either constant-height or constant-distance mode.

Svend-Age Biehs; Oliver Huth; Felix Rüting

2011-03-15T23:59:59.000Z

360

Flexible profile approach to the conjugate heat transfer problem  

E-Print Network (OSTI)

The flexible profile approach proposed earlier to create CTM (compact or reduced order thermal models) is extended to cover the area of conjugate heat transfer. The flexible profile approach is a methodology that allows building a highly boundary conditions independent CTM, with any desired degree of accuracy, that may adequately replace detailed 3D models for the whole spectrum of applications in which the modeled object may be used. The extension to conjugate problems radically solves the problem of interfacing two different domains. Each domain, fluid or solid, can be "compacted" independently creating two CTM that can be joined together to produce reliable results for any arbitrary set of external boundary conditions.

M. -N. Sabry

2008-01-07T23:59:59.000Z

Note: This page contains sample records for the topic "radiant heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Grid-independent Issue in Numerical Heat Transfer  

E-Print Network (OSTI)

Grid independent is associated with the accuracy or even rationality of numerical results. This paper takes two-dimensional steady heat transfer for example to reveal the effect of grid resolution on numerical results. The law of grid dependence is obtained and a simple mathematical formula is presented. The production acquired here can be used as the guidance in choosing grid density in numerical simulation and get exact grid independent value without using infinite fine grid. Through analyzing grid independent, we can find the minimum number of grid cells that is needed to get grid-independent results. Such strategy can save computational resource while ensure a rational computational result.

Yao Wei; Wang Jian; Liao Guangxuan

2006-09-25T23:59:59.000Z

362

Unified Model for the Heat Transfer Processes that Occur During  

E-Print Network (OSTI)

A unified general model for the heat transfer processes that occur within a food product subjected to canning or aseptic thermal treatment, is presented. Two principles are extensively used in the model building process: system segregation and energy balancing. The model is summarized in an algorithm, whose specification is showed for different combinations of processing system type (PST) and product formulation (PF) with a single particle type. A discussion on the practical relevance of proper product identification in the case of aseptic processing, is included. Finally, an illustration is given on the results that can be obtained from the model algorithm application, in a comparative study of different PST-PF combinations.

Jose F. Pastrana; Harvey J. Gold; Kenneth R. Swanzel; Pastrana Gold; Jose F. Pastrana; Harvey J. Gold; Kenneth R. Swartzel

1992-01-01T23:59:59.000Z

363

Effects of Radiant Barrier Systems on Ventilated Attics in a Hot and Humid Climate  

E-Print Network (OSTI)

Results of side-by-side radiant barrier experiments using two identical 144 ft2 (nominal) test houses are presented. The test houses responded very similarly to weather variations prior to the retrofit. The temperatures of the test houses were controlled to within 0.3°F. Ceiling heat fluxes were within 2 percent for each house. The results showed that a critical attic ventilation flow rate (0.25 CFM/ft2 ) existed after which the percentage reduction produced by the radiant barrier systems was not sensitive to increased airflows. The ceiling heat flux reductions produced by the radiant barrier systems were between 25 and 34 percent, with 28 percent being the reduction observed most often in the presence of attic ventilation. All results presented in this paper were for attics with R-19 unfaced fiberglass insulation and for a perforated radiant barrier with low emissivities on both sides.

Medina, M. A.; O'Neal, D. L.; Turner, W. D.

1992-05-01T23:59:59.000Z

364

SunShot Initiative: High Operating Temperature Liquid Metal Heat Transfer  

NLE Websites -- All DOE Office Websites (Extended Search)

High Operating Temperature Liquid High Operating Temperature Liquid Metal Heat Transfer Fluids to someone by E-mail Share SunShot Initiative: High Operating Temperature Liquid Metal Heat Transfer Fluids on Facebook Tweet about SunShot Initiative: High Operating Temperature Liquid Metal Heat Transfer Fluids on Twitter Bookmark SunShot Initiative: High Operating Temperature Liquid Metal Heat Transfer Fluids on Google Bookmark SunShot Initiative: High Operating Temperature Liquid Metal Heat Transfer Fluids on Delicious Rank SunShot Initiative: High Operating Temperature Liquid Metal Heat Transfer Fluids on Digg Find More places to share SunShot Initiative: High Operating Temperature Liquid Metal Heat Transfer Fluids on AddThis.com... Concentrating Solar Power Systems Components Competitive Awards

365

Greenhouse of an underground heat accumulation system  

SciTech Connect

A greenhouse of an underground heat accumulation system is described wherein the radiant energy of the sun or wasted thermal energy is accumulated in the soil below the floor of the greenhouse over a prolonged period of time, and spontaneous release of the accumulated energy into the interior of the greenhouse begins in the wintertime due to a time lag of heat transfer through the soil. The release of the accumulated energy lasts throughout the winter.

Fujie, K.; Abe, K.; Uchida, A.

1983-11-01T23:59:59.000Z

366

Heat transfer augmentation along the tube wall of a louvered fin heat exchanger using practical delta winglets  

E-Print Network (OSTI)

Heat transfer augmentation along the tube wall of a louvered fin heat exchanger using practical surface of louvered fin heat exchangers. It is shown that delta winglets placed on louvered fins produce Elsevier Ltd. All rights reserved. Keywords: Compact heat exchanger; Vortex generator; Louvered fins 1

Thole, Karen A.

367

Heat and mass transfer in unsaturated porous media. Final report  

DOE Green Energy (OSTI)

A preliminary study of heat and water transport in unsaturated porous media is reported. The project provides background information regarding the feasibility of seasonal thermal energy storage in unconfined aquifers. A parametric analysis of the factors of importance, and an annotated bibliography of research findings pertinent to unconfined aquifer thermal energy storage (ATES) are presented. This analysis shows that heat and mass transfer of water vapor assume dominant importance in unsaturated porous media at elevated temperature. Although water vapor fluxes are seldom as large as saturated medium liquid water fluxes, they are important under unsaturated conditions. The major heat transport mechanism for unsaturated porous media at temperatures from 50 to 90/sup 0/C is latent heat flux. The mechanism is nonexistent under saturated conditions but may well control design of unconfined aquifer storage systems. The parametric analysis treats detailed physical phenomena which occur in the flow systems study and demonstrates the temperature and moisture dependence of the transport coefficients of importance. The question of design of an unconfined ATES site is also addressed by considering the effects of aquifer temperature, depth to water table, porous medium flow properties, and surface boundary conditions. Recommendations are made for continuation of this project in its second phase. Both scientific and engineering goals are considered and alternatives are presented.

Childs, S.W.; Malstaff, G.

1982-02-01T23:59:59.000Z

368

Forced flow supercritical helium in a closed heat transfer loop subjected to pulsed heat loads  

Science Conference Proceedings (OSTI)

The superconducting magnets of the tokamak JT-60SA are cooled by means of forced flows of supercritical helium at 4.4 K and 0.5 MPa. The closed loops transfer heat from the magnets to the refrigerator through heat exchangers immersed into a saturated liquid helium bath. An experimental loop was designed to represent a 1/20 scaled down mock-up of JT-60SA central solenoid cooling circuits. This design for keeping the same transit times in the helium circuits

2012-01-01T23:59:59.000Z

369

Indoor Humidity Analysis of an Integrated Radiant Cooling and Desiccant Ventilation System  

E-Print Network (OSTI)

Radiant cooling is credited with improving energy efficiency and enhancing the comfort level as an alternative method of space cooling in mild and dry climates, according to recent research. Since radiant cooling panels lack the capability to remove latent heat, they normally are used in conjunction with an independent ventilation system, which is capable of decoupling the space sensible and latent loads. Condensation concerns limit the application of radiant cooling. This paper studies the dehumidification processes of solid desiccant systems and investigates the factors that affect the humidity levels of a radiantly cooled space. Hourly indoor humidity is simulated at eight different operating conditions in a radiantly cooled test-bed office. The simulation results show that infiltration and ventilation flow rates are the main factors affecting indoor humidity level and energy consumption in a radiantly cooled space with relatively constant occupancy. It is found that condensation is hard to control in a leaky office operated with the required ventilation rate. Slightly pressurizing the space is recommended for radiant cooling. The energy consumption simulation shows that a passive desiccant wheel can recover about 50% of the ventilation load.

Gong, X.; Claridge, D. E.

2006-01-01T23:59:59.000Z

370

The effect of a magnetic field on heat transfer in a slotted channel  

SciTech Connect

The results of numerical and experimental studies of liquid metal heat transfer in slotted channels in a transverse magnetic field are presented. Test results showed an improvement in heat transfer in a straight channel at low and moderate interaction parameter, N. The Nusselt number at small N (around 120) was up to 2 times higher than in turbulent flow without a magnetic field, Peclet number being equal. This effect of heat transfer enhancement is caused by the generation and development of large scale velocity fluctuations in the near heated wall area. Qualitative and quantitative correlations between heat transfer and velocity fluctuation characteristics are presented.

Evtushenko, I.A.; Kirillov, I.R.; Sidorenkov, S.S. [D.V. Efremov Scientific Research Institute of Electrophysical Apparatus, St. Petersburg (Russian Federation); Hua, T.Q.; Reed, C.B. [Argonne National Lab., IL (United States)

1994-07-01T23:59:59.000Z

371

Molecular Dynamics Simulations of Heat Transfer In Nanoscale Liquid Films  

E-Print Network (OSTI)

Molecular Dynamics (MD) simulations of nano-scale flows typically utilize fixed lattice crystal interactions between the fluid and stationary wall molecules. This approach cannot properly model thermal interactions at the wall-fluid interface. In order to properly simulate the flow and heat transfer in nano-scale channels, an interactive thermal wall model is developed. Using this model, the Fourier’s law of heat conduction is verified in a 3.24 nm height channel, where linear temperature profiles with constant thermal conductivity is obtained. The thermal conductivity is verified using the predictions of Green-Kubo theory. MD simulations at different wall wettability ( ??f /? ) and crystal bonding stiffness values (K) have shown temperature jumps at the liquid/solid interface, corresponding to the well known Kapitza resistance. Using systematic studies, the thermal resistance length at the interface is characterized as a function of the surface wettability, thermal oscillation frequency, wall temperature and thermal gradient. An empirical model for the thermal resistance length, which could be used as the jump-coefficient of a Navier boundary condition, is developed. Temperature distributions in the nano-channels are predicted using analytical solution of the continuum heat conduction equation subjected to the new temperature jump condition, and validated using the MD results. Momentum and heat transfer in shear driven nanochannel flows are also investigated. Work done by the viscous stresses heats the fluid, which is dissipated through the channel walls, maintained at isothermal conditions. Spatial variations in the fluid density, kinematic viscosity, shear- and energy dissipation rates are presented. The energy dissipation rate is almost a constant for ??f /? < 0.6, which results in parabolic temperature profiles in the domain with temperature jumps due to the Kapitza resistance at the liquid/solid interfaces. Using the energy dissipation rates predicted by MD simulations and the continuum energy equation subjected to the temperature jump boundary conditions developed in this study, the analytical solutions are obtained for the temperature profiles, which agree well with the MD results.

Kim, Bo Hung

2009-05-01T23:59:59.000Z

372

Conjugate Effects on Steady Laminar Natural Convection Heat Transfer in Vertical Eccentric Annuli  

E-Print Network (OSTI)

Local heat flux on outer interface at channel exit i Index for bi-polar grid in the -directionConjugate Effects on Steady Laminar Natural Convection Heat Transfer in Vertical Eccentric Annuli University of Petroleum and Minerals, Dhahran, Saudi Arabia Combined conduction-free convection heat transfer

Jamal, Ahmad

373

Heating surface material’s effect on subcooled flow boiling heat transfer of R134a  

Science Conference Proceedings (OSTI)

In this study, subcooled flow boiling of R134a on copper (Cu) and stainless steel (SS) heating surfaces was experimentally investigated from both macroscopic and microscopic points of view. By utilizing a high-speed digital camera, bubble growth rate, bubble departure size, and nucleation site density, were able to be observed and analyzed from the microscopic point of view. Macroscopic characteristics of the subcooled flow boiling, such as heat transfer coefficient, were able to be measured as well. Experimental results showed that there are no obvious difference between the copper and the stainless surface with respect to bubble dynamics, such as contact angle, growth rate and departure size. On the contrary, the results clearly showed a trend that the copper surface had a better performance than the stainless steel surface in terms of heat transfer coefficient. It was also observed that wall heat fluxes on both surfaces were found highly correlated with nucleation site density, as bubble hydrodynamics are similar on these two surfaces. The difference between these two surfaces was concluded as results of different surface thermal conductivities.

Ling Zou; Barclay G. Jones

2012-11-01T23:59:59.000Z

374

Flow and heat transfer in a curved pipe with periodically varying curvature  

SciTech Connect

A numerical analysis is carried out for the study of the flow and heat transfer for a laminar flow in a pipe with periodically varying finite (not very small) curvature. The effects of the flow rate (Re), the Prandtl number (Pr), the pipe-period ({kappa}) and the pipe-amplitude (a) on the heat transfer ratio (heat transfer of curved pipe to straight pipe) are studied. The results show that an increase in the amplitude and/or a decrease in the wavelength of a periodic wavy pipe can enhance the heat transfer rate significantly. The ratio of the heat transfer ratio to the friction ratio is greater than one which means a net benefit of heat transfer enhancement.

Yang, R.; Chang, S.F.; Wu, W.

2000-01-01T23:59:59.000Z

375

RELAP5 MODEL OF THE DIVERTOR PRIMARY HEAT TRANSFER SYSTEM  

SciTech Connect

This report describes the RELAP5 model that has been developed for the divertor primary heat transfer system (PHTS). The model is intended to be used to examine the transient performance of the divertor PHTS and evaluate control schemes necessary to maintain parameters within acceptable limits during transients. Some preliminary results are presented to show the maturity of the model and examine general divertor PHTS transient behavior. The model can be used as a starting point for developing transient modeling capability, including control system modeling, safety evaluations, etc., and is not intended to represent the final divertor PHTS design. Preliminary calculations using the models indicate that during normal pulsed operation, present pressurizer controls may not be sufficient to keep system pressures within their desired range. Additional divertor PHTS and control system design efforts may be required to ensure system pressure fluctuation during normal operation remains within specified limits.

Popov, Emilian L [ORNL; Yoder Jr, Graydon L [ORNL; Kim, Seokho H [ORNL

2010-08-01T23:59:59.000Z

376

HEAT TRANSFER IN POROUS MEDIA WITH FLUID PHASE CHANGES  

E-Print Network (OSTI)

Cotter, T. P. : "Theory of Heat Pipe," Report No. LA-3246-L. : "Two Component Heat Pipes, It Propress in Astronauticsthe successful. The 'heat pipe ph periments were quite

Su, Ho-Jeen.

2010-01-01T23:59:59.000Z

377

A method of correlating heat transfer data for surface boiling of liquids  

E-Print Network (OSTI)

A method based an a logical uxplanation of the meani of beat transfer associated with the boiling process is presented for correlating heat transfer data for nucleate boiling of liquids for the case of pool boiling. Tbe ...

Rohsenow, Warren M.

1951-01-01T23:59:59.000Z

378

Heat transfer in inertial confinement fusion reactor systems  

SciTech Connect

The transfer of energy produced by the interaction of the intense pulses of short-ranged fusion microexplosion products with materials is one of the most difficult problems in inertially-confined fusion (ICF) reactor design. The short time and deposition distance for the energy results in local peak power densities on the order of 10/sup 18/ watts/m/sup 3/. High local power densities may cause change of state or spall in the reactor materials. This will limit the structure lifetimes for ICF reactors of economic physical sizes, increasing operating costs including structure replacement and radioactive waste management. Four basic first wall protection methods have evolved: a dry-wall, a wet-wall, a magnetically shielded wall, and a fluid wall. These approaches are distinguished by the way the reactor wall interfaces with fusion debris as well as the way the ambient cavity conditions modify the fusion energy forms and spectra at the first wall. Each of these approaches requires different heat transfer considerations.

Hovingh, J.

1979-05-14T23:59:59.000Z

379

Estimation of Surface Energy Balance from Radiant Surface Temperature and NOAA AVHRR Sensor Reflectances over Agricultural and Native Vegetation  

Science Conference Proceedings (OSTI)

A model is developed to evaluate surface heat flux densities using the radiant surface temperature and red and near-infrared reflectances from the NOAA Advanced Very High Resolution Radiometer sensor. Net radiation is calculated from an empirical ...

Huang Xinmei; T. J. Lyons; R. C. G. Smith; J. M. Hacker; P. Schwerdtfeger

1993-08-01T23:59:59.000Z

380

The Influence of Proposed Repository Thermal Load on Multiphase Flow and Heat Transfer in the Unsaturated Zone of Yucca Mountain  

E-Print Network (OSTI)

22]. Fluid flow and heat-transfer processes in a two-phase,processes associated with multiphase flow and heat transferprocesses has also motivated development of fluid flow and heat transfer

Wu, Y.-S.; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, G.S.

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "radiant heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Cloud Color and Ocean Radiant Heating  

Science Conference Proceedings (OSTI)

It is well recognized that clouds regulate the flux of solar radiation reaching the sea surface. Clouds also affect the spectral distribution of incident irradiance. Observations of spectral and total incident solar irradiance made from the ...

David A. Siegel; Toby K. Westberry; J. Carter Ohlmann

1999-04-01T23:59:59.000Z

382

Ocean Radiant Heating in Climate Models  

Science Conference Proceedings (OSTI)

A computationally simple, double exponential, chlorophyll-dependent solar transmission parameterization for ocean general circulation models used in climate studies is presented. The transmission parameterization comes from empirical fits to a ...

J. Carter Ohlmann

2003-05-01T23:59:59.000Z

383

Development of periodic response factors for use with the radiant time series method  

SciTech Connect

Harris and McQuiston (1988) developed conduction transfer function (CTF) coefficients corresponding to 41 representative wall assemblies and 42 representative roof assemblies for use with the transfer function method (TFM). They also developed a grouping procedure that allows design engineers to determine the correct representative wall or roof assembly that most closely matches a specific wall or roof assembly. The CTF coefficients and the grouping procedure have been summarized in the ASHRAE Handbook--Fundamentals (1989, 1993, 1997) and the ASHRAE Cooling and Heating Load Calculation Manual, second edition. More recently, a new, simplified design cooling load calculation procedure, the radiant time series method (RTSM), has been developed. The RTSM uses periodic response factors to model transient conductive heat transfer. While not a true manual load calculation procedure, it is quite feasible to implement the RTSM in a spreadsheet. To be useful in such an environment, it would be desirable to have a pre-calculated set of periodic response factors. Accordingly, a set of periodic response factors has been calculated and is presented in this paper.

Spitler, J.D.; Fisher, D.E.

1999-07-01T23:59:59.000Z

384

Heat transfer characteristics of a two-phase, air-water direct contact evaporator.  

E-Print Network (OSTI)

??The purpose of the research was to carry out an experimental and theoretical investigation of the heat transfer on a direct contact column for desalination… (more)

Zanette, Luca

2013-01-01T23:59:59.000Z

385

Application of mechanistic models for flow distribution and heat transfer in finned tube bundles.  

E-Print Network (OSTI)

?? The focus of this thesis was heat transfer and pressure drop in staggered tube bundles with solid and serrated fins. The first part of… (more)

Eikill, Astrid Oygarden

2013-01-01T23:59:59.000Z

386

Flow fields and heat transfer of liquid falling film on horizontal cylinders.  

E-Print Network (OSTI)

??A liquid film flowing over horizontal cylinders is of great importance as a high rate of heat transfer exists between the falling liquid film and… (more)

Jafar, Farial A

2011-01-01T23:59:59.000Z

387

Design and evaluation of heat transfer fluids for direct immersion cooling of electronic systems .  

E-Print Network (OSTI)

??Comprehensive molecular design was used to identify new heat transfer fluids for direct immersion phase change cooling of electronic systems. Four group contribution methods for… (more)

Harikumar Warrier, Pramod Kumar Warrier

2012-01-01T23:59:59.000Z

388

Application Of A Spherical-Radial Heat Transfer Model To Calculate...  

Open Energy Info (EERE)

Application Of A Spherical-Radial Heat Transfer Model To Calculate Geothermal Gradients From Measurements In Deep Boreholes Jump to: navigation, search GEOTHERMAL ENERGYGeothermal...

389

Impingement cooling and heat transfer measurement using transient liquid crystal technique.  

E-Print Network (OSTI)

??A heat transfer study on jet impingement cooling is presented. The study focuses on the effect of impingement jet flow rate, jet angle, and flow… (more)

Huang, Yizhe

2012-01-01T23:59:59.000Z

390

Modeling of Heat Transfer during Cooling of a Hot Steel Plate  

Science Conference Proceedings (OSTI)

Thus, it is crucial to develop accurate heat transfer models in order to predict the temperature history during cooling of steel plates. The present study describes a  ...

391

Heat transfer modeling at an interface between a porous medium and a free region.  

E-Print Network (OSTI)

??This work deals with the study of heat transfer between a porous medium and a free medium, using multi scale approaches. First, we derive the… (more)

D'hueppe, Aliénor

2011-01-01T23:59:59.000Z

392

Dynamic wetting and heat transfer behaviour of aluminium droplets impinging and solidifying on copper substrates.  

E-Print Network (OSTI)

??The present work describes an experimental set-up built to simulate dynamic wetting and heat transfer occurring in many rapid solidification processes. Tests were performed with… (more)

Leboeuf, Sébastien

2004-01-01T23:59:59.000Z

393

Heat transfer to and from a reversible thermosiphon placed in porous media.  

E-Print Network (OSTI)

??The primary focus of this work is an assessment of heat transfer to and from a reversible thermosiphon imbedded in porous media. The interest in… (more)

Kekelia, Bidzina

2012-01-01T23:59:59.000Z

394

The Development of a Non-Equilibrium Dispersed Flow Film Boiling Heat Transfer Modeling Package.  

E-Print Network (OSTI)

??The dispersed flow film boiling (DFFB) heat transfer regime is important to several applications including cryogenics, rocket engines, steam generators, and in the safety analysis… (more)

Meholic, Michael

2011-01-01T23:59:59.000Z

395

Developing Low-Conductance Window Frames: Capabilities and Limitations of Current Window Heat Transfer Design Tools  

E-Print Network (OSTI)

and spacer effects on window U- value. ASHRAE Transactions,Enermodal. (2001). Modelling Windows, Glass Doors and OtherA. (2001). Heat transfer in window frames with internal

Gustavsen, Arild

2009-01-01T23:59:59.000Z

396

Effect of TiO2 on the Conduction Heat Transfer of Mold Flux  

Science Conference Proceedings (OSTI)

Symposium, 2nd International Symposium on High-Temperature Metallurgical Processing. Presentation Title, Effect of TiO2 on the Conduction Heat Transfer of

397

The Study of Heat and Mass Transfer In The Generator For an Absorption Air Conditioning System.  

E-Print Network (OSTI)

??This thesis is aimed to study the heat and mass transfer performance of a generator for the absorption cooling system. Both aqueous lithium bromide (LiBr)… (more)

Hsu, Yu-lien

2012-01-01T23:59:59.000Z

398

Heat and mass transfer in deep fat frying of breaded chicken nuggets.  

E-Print Network (OSTI)

??This study presents techniques that can be applied to optimize the quality of coated fried chicken nuggets. Heat and mass transfer during deep fat frying… (more)

Wang, Yunfeng, 1970-

2005-01-01T23:59:59.000Z

399

W-12: Determination of Interfacial Heat Transfer and Air-gap ...  

Science Conference Proceedings (OSTI)

It is predicted for the Nickel-based alloy when the air-gap is below 0.3mm heat conduction is the dominant heat transfer process; above 0.3mm radiation is the ...

400

Program on Technology Innovation: Applications of Nanofluids to Enhance Heat Transfer in Nuclear Reactors  

Science Conference Proceedings (OSTI)

Advances in electronics and heat transfer systems require an improved energy removal rate from heated surfaces. Nanofluidsengineered colloidal dispersions of nano-size (1100 nm) particles in common fluids such as waterhave been found to enhance heat transfer properties. Because the primary mechanism of critical heat flux (CHF) enhancement results from the surface deposition of nanoparticles, nanofluids can be applied in two ways: through direct use as an advanced coolant and as a process coolant for in s...

2009-11-17T23:59:59.000Z

Note: This page contains sample records for the topic "radiant heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Heat Transfer Analysis of Asphalt Concrete Pavement Based on Snow Melting  

Science Conference Proceedings (OSTI)

On the basis of Wuhan district weather conditions of January 5, 2010, heat transfer mechanism of Beijing-Zhuhai Expressway Hubei section of asphalt concrete pavement based on snow melting is analyzed and the model of heat transmission is established. ... Keywords: asphalt concrete pavement, ground-source heat, pump, deicing and snow melting, heat flux

Yan-ping Tu; Jie Li; Chang-sheng Guan

2010-06-01T23:59:59.000Z

402

Heat transfer and pressure drop for air flow through enhanced passages. Final report  

SciTech Connect

An extensive experimental investigation was carried out to determine the pressure drop and heat transfer characteristics for laminar, transitional and turbulent flow of air through a smooth passage and twenty-three enhanced passages. The internal surfaces of all enhanced passages had spirally shaped geometries; these included fluted, finned/ribbed and indented surfaces. The Reynolds number (Re) was varied between 400 and 50000. The effect of heat transfer (wall cooling or fluid heating) on pressure drop is most significant within the transition region; the recorded pressure drop with heat transfer is much higher than that without heat transfer. The magnitude of this effect depends markedly on the average surface temperature and, to a lesser extent, on the geometric characteristics of the enhanced surfaces. When the pressure drop data are reduced as values of the Fanning friction factor(f), the results are about the same with and without heat transfer for turbulent flow, with moderate differences in the laminar and transition regions.

Obot, N.T.; Esen, E.B.

1992-06-01T23:59:59.000Z

403

Heat transfer and pressure drop for air flow through enhanced passages  

SciTech Connect

An extensive experimental investigation was carried out to determine the pressure drop and heat transfer characteristics for laminar, transitional and turbulent flow of air through a smooth passage and twenty-three enhanced passages. The internal surfaces of all enhanced passages had spirally shaped geometries; these included fluted, finned/ribbed and indented surfaces. The Reynolds number (Re) was varied between 400 and 50000. The effect of heat transfer (wall cooling or fluid heating) on pressure drop is most significant within the transition region; the recorded pressure drop with heat transfer is much higher than that without heat transfer. The magnitude of this effect depends markedly on the average surface temperature and, to a lesser extent, on the geometric characteristics of the enhanced surfaces. When the pressure drop data are reduced as values of the Fanning friction factor(f), the results are about the same with and without heat transfer for turbulent flow, with moderate differences in the laminar and transition regions.

Obot, N.T.; Esen, E.B.

1992-06-01T23:59:59.000Z

404

Steady-state heat transfer in an inverted U-tube steam generator  

SciTech Connect

Experimental results are presented involving U-tube steam generator tube bundle local heat transfer and fluid conditions during steady-state, full-power operations performed at high temperatures and pressures with conditions typical of a pressurized water reactor (15.0 MPa primary pressure, 600 K hot-leg fluid temperatures, 6.2 MPa secondary pressure). The MOD-2C facility represents the state-of-the-art in measurement of tube local heat transfer data and average tube bundle secondary fluid density at several elevations, which allows an estimate of the axial heat transfer and void distributions during steady-state and transient operations. The method of heat transfer data reduction is presented and the heat flux, secondary convective heat transfer coefficient, and void fraction distributions are quantified for steady-state, full-power operations.

Boucher, T.J.

1986-01-01T23:59:59.000Z

405

Steady-state heat transfer in an inverted U-tube steam generator  

Science Conference Proceedings (OSTI)

Experimental results are presented involving U-tube steam generator tube bundle local heat transfer and fluid conditions during stead-state, full-power operations performed at high temperatures and pressures with conditions typical of a pressurized water reactor (15.0 MPa primary pressure, 600 K steam generator inlet plenum fluid temperatures, 6.2 MPa secondary pressure). The Semiscale (MOD-2C facility represents the state-of-the-art in measurement of tube local heat transfer data and average tube bundle secondary fluid density at several elevations, which allows an estimate of the axial heat transfer and void distributions during steady-state and transient operations. The method of heat transfer data reduction is presented and the heat flux, secondary convective heat transfer coefficient, and void fraction distributions are quantified for steady-state, full-power operations.

Boucher, T.J.

1987-01-01T23:59:59.000Z

406

Experimental study of natural convection heat transfer through an aperture in passive solar heated buildings  

DOE Green Energy (OSTI)

The objective of this study is to obtain correlations between natural convection heat transfer through an aperture and temperature difference between the two rooms. A one-fifth similitude model of a two-room building is used. The model is filled with Freon gas to satisfy similarity of the experiment to full-scale conditions in air. The experimental apparatus and experimental techniques are explained. Experimental results are presented in terms of Grashof, Nusselt, and Prandtl numbers. The effects of the height, the width, and the vertical position of the apertures are investigated, as is the effect of the room volume.

Yamaguchi, Kenjiro

1984-01-01T23:59:59.000Z

407

USING LIGA BASED MICROFABRICATION TO IMPROVE OVERALL HEAT TRANSFER EFFICIENCY OF PRESSURIZED WATER REACTOR: I. Effects of Different Micro Pattern on Overall Heat Transfer.  

SciTech Connect

The Pressurized Water Reactors (PWRs in Figure 1) were originally developed for naval propulsion purposes, and then adapted to land-based applications. It has three parts: the reactor coolant system, the steam generator and the condenser. The Steam generator (a yellow area in Figure 1) is a shell and tube heat exchanger with high-pressure primary water passing through the tube side and lower pressure secondary feed water as well as steam passing through the shell side. Therefore, a key issue in increasing the efficiency of heat exchanger is to improve the design of steam generator, which is directly translated into economic benefits. The past research works show that the presence of a pin-fin array in a channel enhances the heat transfer significantly. Hence, using microfabrication techniques, such as LIGA, micro-molding or electroplating, some special microstructures can be fabricated around the tubes in the heat exchanger to increase the heat-exchanging efficiency and reduce the overall size of the heat-exchanger for the given heat transfer rates. In this paper, micro-pin fins of different densities made of SU-8 photoresist are fabricated and studied to evaluate overall heat transfer efficiency. The results show that there is an optimized micro pin-fin configuration that has the best overall heat transfer effects.

Zhang, M.; Ibekwe, S.; Li, G.; Pang, S.S.; and Lian, K.

2006-07-01T23:59:59.000Z

408

Two-dimensional computational fluid dynamics and conduction simulations of heat transfer in window frames with internal cavities - Part 1: Cavities only  

E-Print Network (OSTI)

of heat fluxes from CFD and conduction simulations for theapproach to solve the conduction heat-transfer equation. TheFluid Dynamics and Conduction Simulations of Heat Transfer

Gustavsen, Arild; Kohler, Christian; Arasteh, Dariush; Curcija, Dragan

2003-01-01T23:59:59.000Z

409

Ventilation and Solar Heat Storage System Offers Big Energy Savings  

Ventilation and Solar Heat Storage System Offers Big Energy Savings ... Heat is either reflected away from the building with radiant barriers, or heat is absorbed

410

Numerical Investigation of Air-Side Heat Transfer and Pressure Drop in Circular Finned-Tube Heat Exchangers.  

E-Print Network (OSTI)

??A three-dimensional numerical study is performed to investigate the heat transfer and pressure drop performance on the air-side of circular finned tube bundles in cross… (more)

Mon, Mi Sandar

2003-01-01T23:59:59.000Z

411

Estimation of Sensible and Latent Heat Fluxes from Soil Surface Temperature Using a Linear Air-Land Heat Transfer Model  

Science Conference Proceedings (OSTI)

The authors present a linearized model of the heat transfer between the soil layer and the atmosphere. Using this model, the moisture availability at the surface can be estimated from the diurnal variations of the soil surface temperature and ...

Fujio Kimura; Yugo Shimizu

1994-04-01T23:59:59.000Z

412

Micro and nanostructured surfaces for enhanced phase change heat transfer  

E-Print Network (OSTI)

Two-phase microchannel heat sinks are of significant interest for thermal management applications, where the latent heat of vaporization offers an efficient method to dissipate large heat fluxes in a compact device. However, ...

Chu, Kuang-Han, Ph. D. Massachusetts Institute of Technology

2013-01-01T23:59:59.000Z

413

HEAT TRANSFER IN POROUS MEDIA WITH FLUID PHASE CHANGES  

E-Print Network (OSTI)

percent compared with heat conduction alone. likely to occurThus, in addition to heat conduction, a large amount ofFourier's law for heat conduction, and the mass balance and

Su, Ho-Jeen.

2010-01-01T23:59:59.000Z

414

Center for Energy Efficiency and Renewable Energy at University of Massachusetts 3D Model of Heat Transfer and Fluid3D Model of Heat Transfer and Fluid  

E-Print Network (OSTI)

Center for Energy Efficiency and Renewable Energy at University of Massachusetts 3D Model of Heat for Energy Efficiency and Renewable Energy at University of Massachusetts 3D Model of Heat Transfer and Fluid WindowModeling a 3D Window Future WorkFuture Work #12;Center for Energy Efficiency and Renewable Energy

Massachusetts at Amherst, University of

415

Modeling with finite element the convective heat transfer in civil building EPS insulated walls  

Science Conference Proceedings (OSTI)

In this paper we present the analysis of convective heat transfer in the walls of a house insulated with polystyrene. In the first part we make an evaluation of the insulation that is currently used in the houses. We start the simulation using a real ... Keywords: convective heat transfer, dew-point, finite element, polystyrene insulation

Madalina Xenia Calbureanu; Mihai Lungu; Dragos Tutunea; Raluca Malciu; Alexandru Dima

2010-10-01T23:59:59.000Z

416

Adaptive higher order numerical simulation of heat and mass transfer in fluidized beds  

E-Print Network (OSTI)

Adaptive higher order numerical simulation of heat and mass transfer in fluidized beds Ch. Nagaiah1 adaptive numerical results of heat and mass transfer in fluidized beds using higher order time stepping injection. The numerical results are tested with different time stepping methods for different spatial grid

Magdeburg, Universität

417

Effect of surface conditions on boiling heat transfer of refrigerants in shell-and-tube evaporators  

Science Conference Proceedings (OSTI)

Experimental results are presented for the boiling heat transfer performance of R 22 and R 717 on surfaces with porous metallized coatings. A calculational-theoretical model is given for predicting the heat transfer of refrigerants boiling on a bundle of finned tubes.

Danilova, G.N.; Dyundin, V.A.; Borishanskaya, A.V.; Soloviyov, A.G.; Vol'nykh, Y.A.; Kozyrev, A.A.

1990-01-01T23:59:59.000Z

418

A Numerical Study on the Enhancement of Heat Transfer by Pressure Distributions in Acoustic Fields  

Science Conference Proceedings (OSTI)

The enhancement of heat transfer in a cavity was investigated in the absence of and in the presence of acoustic streaming induced by ultrasonic waves. The present study provides the experimental and numerical results of heat transfer in the acoustic ... Keywords: Acoustic pressure, Acoustic streaming, Coupled FE-BEM, Particle imaging velocimetry (PIV), Ultrasonic wave

Y. K. Oh; H. D. Yang

2005-01-01T23:59:59.000Z

419

Solving of non-stationary heat transfer in a plane plate  

Science Conference Proceedings (OSTI)

In this paper we present software application destined for study of heat transfer problems that is a part of education of subject Process engineering taught at the Tomas Bata University in Zlin. The application we use as a teaching aid for calculation ... Keywords: maple, non-stationary heat transfer, software application, temperature field

Dagmar Janá?ová; Hana Charvátová; Karel Kolomazník; Vladimír Vašek; Pavel Mokrejš

2011-05-01T23:59:59.000Z

420

Rod Bundle Heat Transfer for Pressurized Water Reactors at Operating Conditions  

Science Conference Proceedings (OSTI)

Currently available heat transfer correlations for subcooled forced convection and subcooled boiling have not been validated with rod-array data at typical PWR fluid conditions. At the present time, rod bundle heat transfer processes cannot be analyzed with sufficient accuracy to make sound decisions regarding changes that might avoid an Axial Offset Anomaly (AOA).

2000-07-14T23:59:59.000Z

Note: This page contains sample records for the topic "radiant heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Collisionless inter-species energy transfer and turbulent heating in drift wave turbulence  

Science Conference Proceedings (OSTI)

We reconsider the classic problems of calculating 'turbulent heating' and collisionless inter-species transfer of energy in drift wave turbulence. These issues are of interest for low collisionality, electron heated plasmas, such as ITER, where collisionless energy transfer from electrons to ions is likely to be significant. From the wave Poynting theorem at steady state, a volume integral over an annulus r{sub 1}heating as {integral}{sub r{sub 1}} {sup r{sub 2}} dr=-S{sub r}|{sub r{sub 1}{sup r{sub 2}}}{ne}0. Here S{sub r} is the wave energy density flux in the radial direction. Thus, a wave energy flux differential across an annular region indeed gives rise to a net heating, in contrast to previous predictions. This heating is related to the Reynolds work by the zonal flow, since S{sub r} is directly linked to the zonal flow drive. In addition to net heating, there is inter-species heat transfer. For collisionless electron drift waves, the total turbulent energy source for collisionless heat transfer is due to quasilinear electron cooling. Subsequent quasilinear ion heating occurs through linear ion Landau damping. In addition, perpendicular heating via ion polarization currents contributes to ion heating. Since at steady state, Reynolds work of the turbulence on the zonal flow must balance zonal flow frictional damping ({approx}{nu}{sub ii}{sup 2}{approx}|(e{phi}(tilde sign)/T)|{sup 4}), it is no surprise that zonal flow friction appears as an important channel for ion heating. This process of energy transfer via zonal flow has not previously been accounted for in analyses of energy transfer. As an application, we compare the rate of turbulent energy transfer in a low collisionality plasma with the rate of the energy transfer by collisions. The result shows that the collisionless turbulent energy transfer is a significant energy coupling process for ITER plasma.

Zhao, L. [Center for Astrophysics and Space Sciences and Department of Physics, University of California at San Diego, La Jolla, California 92093-0424 (United States); Diamond, P. H. [Center for Astrophysics and Space Sciences and Department of Physics, University of California at San Diego, La Jolla, California 92093-0424 (United States); WCI Center for Fusion Theory, National Fusion Research Institute, Gwahangno113, Yuseong-gu, Daejeon 305-333 (Korea, Republic of)

2012-08-15T23:59:59.000Z

422

Vibration damping and heat transfer using material phase changes  

SciTech Connect

A method and apparatus wherein phase changes in a material can dampen vibrational energy, dampen noise and facilitate heat transfer. One embodiment includes a method for damping vibrational energy in a body. The method comprises attaching a material to the body, wherein the material comprises a substrate, a shape memory alloy layer, and a plurality of temperature change elements. The method further comprises sensing vibrations in the body. In addition, the method comprises indicating to at least a portion of the temperature change elements to provide a temperature change in the shape memory alloy layer, wherein the temperature change is sufficient to provide a phase change in at least a portion of the shape memory alloy layer, and further wherein the phase change consumes a sufficient amount of kinetic energy to dampen at least a portion of the vibrational energy in the body. In other embodiments, the shape memory alloy layer is a thin film. Additional embodiments include a sensor connected to the material.

Kloucek, Petr (Houston, TX); Reynolds, Daniel R. (Oakland, CA)

2009-03-24T23:59:59.000Z

423

Convective heat and mass transfer in compact regenerative dehumidifiers  

Science Conference Proceedings (OSTI)

Regular-density silica gel is identified as the candidate desiccant for regenerative dehumidification of humid air operating at low-regeneration temperatures and high-process humidities. The literature on the equilibrium sorption uptake of water vapor by R. D. silica gel is reviewed in this work, and a large number of experimental sorption data is collected from various technical reports. The Dubinin-Polanyi sorption theory for microporous adsorbents is discussed and applied to the sorptive data. A graphical presentation of the experimental data establishes the characteristic curve for the sorption of water vapor on silica gel. The Dubinin-Astakhov correlation is used to represent the equilibrium sorption isotherm and values for the characteristic sorption energies are determined by curve fitting with the experimental data. An accurate, generalized isotherm equation for the sorption of water vapor on regular density silica gel is presented in the first part of this work. The second part of this work presents an analytical and experimental investigation of the transient heat and mass transfer in laminar flow of humid air over a silica gel surface. Experimental results are presented for the transient response of a parallel-plate dehumidifier matrix in single-blow type experiments.

Van den Buick, E.

1987-01-01T23:59:59.000Z

424

Dual-circuit embossed-sheet heat-transfer panel  

DOE Patents (OSTI)

A heat transfer panel provides redundant cooling for fusion reactors or the like environment requiring low-mass construction. Redundant cooling is provided by two independent cooling circuits, each circuit consisting of a series of channels joined to inlet and outlet headers. The panel comprises a welded joinder of two full-size and two much smaller partial-size sheets. The first full-size sheet is embossed for form first portions of channels for the first and second circuits, as well as a header for the first circuit. The second full-sized sheet is then laid over and welded to the first full-size sheet. The first and second partial-size sheets are then overlaid on separate portions of the second full-sized sheet, and are welded thereto. The first and second partial-sized sheets are embossed to form inlet and outlet headers, which communicate with channels of the second circuit through apertures formed in the second full-sized sheet.

Morgan, G.D.

1982-08-23T23:59:59.000Z

425

Heat transfer between stratified immiscible liquid layers driven by gas bubbling across the interface  

SciTech Connect

The modeling of molten core debris in the CORCON and VANESA computer codes as overlying, immiscible liquid layers is discussed as it relates to the transfer of heat and mass between the layers. This initial structure is identified and possible configurations are discussed. The stratified, gas-sparged configuration that is presently employed in CORCON and VANESA is examined and the existing literature for interlayer heat transfer is assessed. An experiment which was designed to measure interlayer heat transfer with gas sparging is described. The results are presented and compared to previously existing models. A dimensionless correlation for stratified, interlayer heat transfer with gas sparging is developed. This relationship is recommended for inclusion in CORCON-MOD2 for heat transfer between stratified, molten liquid layers. 12 refs., 6 figs., 3 tabs.

Greene, G.A.; Irvine, T.F. Jr.

1988-01-01T23:59:59.000Z

426

Exact microscopic theory of electromagnetic heat transfer between a dielectric sphere and plate  

E-Print Network (OSTI)

Near-field electromagnetic heat transfer holds great potential for the advancement of nanotechnology. Whereas far-field electromagnetic heat transfer is constrained by Planck's blackbody limit, the increased density of states in the near-field enhances heat transfer rates by orders of magnitude relative to the conventional limit. Such enhancement opens new possibilities in numerous applications, including thermal-photo-voltaics, nano-patterning, and imaging. The advancement in this area, however, has been hampered by the lack of rigorous theoretical treatment, especially for geometries that are of direct experimental relevance. Here we introduce an efficient computational strategy, and present the first rigorous calculation of electromagnetic heat transfer in a sphere-plate geometry, the only geometry where transfer rate beyond blackbody limit has been quantitatively probed at room temperature. Our approach results in a definitive picture unifying various approximations previously used to treat this problem, and provides new physical insights for designing experiments aiming to explore enhanced thermal transfer.

Clayton Otey; Shanhui Fan

2011-03-14T23:59:59.000Z

427

Engineering Model of Liquid Storage Utility Tank for Heat Transfer Analysis  

SciTech Connect

The utility or chemical storage tank requires special engineering attention and heat transfer analysis because the tank content is very sensitive to temperature and surrounding environment such as atmospheric or outside air, humidity, and solar radiation heat. A simplified heat transfer model was developed to calculate the liquid content temperature of utility storage tank. The content of the utility storage tanks can be water or any other chemical liquid. An engineering model of liquid storage tank for heat transfer analysis and temperature calculations are presented and discussed in the examples of Tanks No. 1 containing oxalic acid and No. 2 containing sodium tetraphenylborate solution.

Kwon, K.C.

1995-09-27T23:59:59.000Z

428

Ground-Coupled Heat and Moisture Transfer from Buildings; Part 2: Application (Preprint)  

DOE Green Energy (OSTI)

In this paper the effects of moisture on the heat transfer from two basic types of building foundations, a slab-on-grade and a basement, are examined. A two-dimensional finite element heat and moisture transfer program is used to show the effects of precipitation, soil type, foundation insulation, water table depth, and freezing on the heat transfer from the building foundation. Comparisons are made with a simple heat conduction model to illustrate the dependency of the soil thermal conductivity on moisture content.

Deru, M.P. (National Renewable Energy Laboratory); Kirkpatrick, A.T. (Colorado State University)

2001-02-21T23:59:59.000Z

429

Downflow heat transfer in a heated ribbed vertical annulus with a cosine power profile  

Science Conference Proceedings (OSTI)

Experiments designed to investigate downflow heat transfer in a heated, ribbed annulus test section simulating one of the annular coolant channels of a Savannah River Plant production reactor Mark 22 fuel assembly have been conducted at the Idaho National Engineering Laboratory. The inner surface of the annulus was constructed of aluminum and was electrically heated to provide an axial cosine power profile and a flat azimuthal power shape. Data presented in this report are from the ECS-2c series, which was a follow on series to the ECS-2b series, conducted specifically to provide additional data on the effect of different powers at the same test conditions, for use in evaluation of possible power effects on the aluminum temperature measurements. Electrical powers at 90%, 100%, and 110% of the power required to result in the maximum aluminum temperature at fluid saturation temperature were used at each set of test conditions previously used in the ECS-2b series. The ECS-2b series was conducted in the same test rig as the previous ECS-2b series. Data and experimental description for the ECS-2b series is provided in a previous report. 18 refs., 25 figs., 3 tabs.

Anderson, J.L.; Condie, K.G.; Larson, T.K.

1991-10-01T23:59:59.000Z

430

Heat Transfer Analysis and Modeling of a Parabolic Trough Solar Receiver Implemented in Engineering Equation Solver  

DOE Green Energy (OSTI)

This report describes the development, validation, and use of a heat transfer model implemented in Engineering Equation Solver. The model determines the performance of a parabolic trough solar collector's linear receiver, also called a heat collector element. All heat transfer and thermodynamic equations, optical properties, and parameters used in the model are discussed. The modeling assumptions and limitations are also discussed, along with recommendations for model improvement.

Forristall, R.

2003-10-01T23:59:59.000Z

431

Theoretical Design of Thermosyphon for Process Heat Transfer from NGNP to Hydrogen Plant  

DOE Green Energy (OSTI)

The Next Generation Nuclear Plant (NGNP) will most likely produce electricity and process heat, with both being considered for hydrogen production. To capture nuclear process heat, and transport it to a distant industrial facility requires a high temperature system of heat exchangers, pumps and/or compressors. The heat transfer system is particularly challenging not only due to the elevated temperatures (up to ~ 1300K) and industrial scale power transport (=50 MW), but also due to a potentially large separation distance between the nuclear and industrial plants (100+m) dictated by safety and licensing mandates. The work reported here is the preliminary analysis of two-phase thermosyphon heat transfer performance with alkali metals. A thermosyphon is a device for transporting heat from one point to another with quite extraordinary properties. In contrast to single-phased forced convective heat transfer via ‘pumping a fluid’, a thermosyphon (also called a wickless heat pipe) transfers heat through the vaporization / condensing process. The condensate is further returned to the hot source by gravity, i.e. without any requirement of pumps or compressors. With this mode of heat transfer, the thermosyphon has the capability to transport heat at high rates over appreciable distances, virtually isothermally and without any requirement for external pumping devices. Two-phase heat transfer by a thermosyphon has the advantage of high enthalpy transport that includes the sensible heat of the liquid, the latent heat of vaporization, and vapor superheat. In contrast, single-phase forced convection transports only the sensible heat of the fluid. Additionally, vapor-phase velocities within a thermosyphon are much greater than single-phase liquid velocities within a forced convective loop. Thermosyphon performance can be limited by the sonic limit (choking) or vapor flow and/or by condensate entrainment. Proper thermosyphon requires analysis of both.

Piyush Sabharwall; Mike Patterson; Fred Gunnerson

2008-09-01T23:59:59.000Z

432

Experimental study of natural convective heat transfer in a vertical hexagonal sub channel  

Science Conference Proceedings (OSTI)

The development of new practices in nuclear reactor safety aspects and optimization of recent nuclear reactors, including the APWR and the PHWR reactors, needs a knowledge on natural convective heat transfer within sub-channels formed among several nuclear fuel rods or heat exchanger tubes. Unfortunately, the currently available empirical correlation equations for such heat transfer modes are limited and researches on convective heat transfer within a bundle of vertical cylinders (especially within the natural convection modes) are scarcely done. Although boundary layers around the heat exchanger cylinders or fuel rods may be dominated by their entry regions, most of available convection correlation equations are for fully developed boundary layers. Recently, an experimental study on natural convective heat transfer in a subchannel formed by several heated parallel cylinders that arranged in a hexagonal configuration has been being done. The study seeks for a new convection correlation for the natural convective heat transfer in the sub-channel formed among the hexagonal vertical cylinders. A new convective heat transfer correlation equation has been obtained from the study and compared to several similar equations in literatures.

Tandian, Nathanael P.; Umar, Efrizon; Hardianto, Toto; Febriyanto, Catur [Faculty of Mechanical and Aerospace Engineering, Institut Teknologi Bandung, Jl. Ganesa 10, Bandung 40132 (Indonesia); Nuclear Technology Center for Materials and Radiometry, National Nuclear Energy Agency, Bandung (Indonesia); Faculty of Mechanical and Aerospace Engineering, Institut Teknologi Bandung, Jl. Ganesa 10, Bandung 40132 (Indonesia); Nuclear Energy Regulation Agency, Jakarta (Indonesia)

2012-06-06T23:59:59.000Z

433

International Communications in Heat and Mass Transfer, volume 39, issue 10, December 2012, Pages 15191521.  

E-Print Network (OSTI)

.P. Hodson, T.J. Lu, Fluid-flow and endwall heat-transfer characteristics of an ultralight lattice and water as the working fluid. Thermodynamic design principles for a multifunctional heat pipe sandwich.P. Hodson, D.T. Queheillalt, D.J. Sypeck, H.N.G. Wadley, The effects of topology upon fluid-flow and heat

Cambridge, University of

434

Apparatus and method for controlling heat transfer between a fluidized bed and tubes immersed therein  

DOE Patents (OSTI)

In a fluidized bed of solid particles having one or more heat exchange tubes immersed therein, the rate of heat transfer between the fluidized particles and a fluid flowing through the immersed heat exchange tubes is controlled by rotating an arcuate shield apparatus about each tube to selectively expose various portions of the tube to the fluidized particles.

Hodges, James L. (3 Hilltop Ave., Vernon, CT 06066); Cerkanowicz, Anthony E. (8 Fieldstone Dr., Livingston, NJ 07039)

1983-01-01T23:59:59.000Z

435

Apparatus and method for controlling heat transfer between a fluidized bed and tubes immersed therein  

DOE Patents (OSTI)

In a fluidized bed of solid particles having one or more heat exchange tubes immersed therein, the rate of heat transfer between the fluidized particles and a fluid flowing through the immersed heat exchange tubes is controlled by rotating an arcuate shield apparatus about each tube to selectively expose various portions of the tube to the fluidized particles.

Hodges, James L. (3 Hilltop Ave., Vernon, CT 06066); Cerkanowicz, Anthony E. (8 Fieldstone Dr., Livingston, NJ 07039)

1982-01-01T23:59:59.000Z

436

Generator-Absorber heat exchange transfer apparatus and method using an intermediate liquor  

DOE Patents (OSTI)

Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium where the working solution has an intermediate liquor concentration.

Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI)

1996-11-05T23:59:59.000Z

437

Numerical simulation of fluid flow and heat transfer in a water heater  

Science Conference Proceedings (OSTI)

Energy consumption represents a major concern, considering the limited resources and latest targets for lower emissions of carbon dioxide. Therefore design of electric heating elements for household and industry are more and more subject to optimization, ... Keywords: electric heating, finite elements, fluid flow, heat transfer

Mircea Nicoar?; Aurel R?du??; Lauren?iu Roland Cucuruz; Cosmin Locovei

2010-04-01T23:59:59.000Z

438

Energy, cost, and CO 2 emission comparison between radiant wall panel systems and radiator systems  

E-Print Network (OSTI)

The main goal of this paper is to evaluate the possibility of application or replacement of radiators with low-temperature radiant panels. This paper shows the comparison results of operations of 4 space heating systems: the low-temperature radiant panel system without any additional thermal insulation of external walls (PH-WOI), the low-temperature radiant panel system with additional thermal insulation of external walls (PH-WI), the radiator system without any additional thermal insulation of external walls (the classical heating system) (RH-WOI), and the radiator system with additional thermal insulation of external walls (RH-WI). The operation of each system is simulated by software EnergyPlus. The investigation shows that the PH-WI gives the best results. The RH-WOI has the largest energy consumption, and the largest pollutant emission. However, the PH-WI requires the highest investment.

Milorad Boji?; Dragan Cvetkovi?; Marko Mileti?; Jovan Maleševi?; Harry Boyer

2012-12-18T23:59:59.000Z

439

Effects of particle concentration and surfactant use in convective heat transfer of CuO nanofluids in microchannel flow.  

E-Print Network (OSTI)

??Heat exchange systems used in everything from cars to microelectronics have rapidly advanced in recent years to offer high heat transfer rates in increasingly smaller… (more)

Byrne, Matthew Davidson

2011-01-01T23:59:59.000Z

440

Advanced multistage turbine blade aerodynamics, performance, cooling, and heat transfer  

DOE Green Energy (OSTI)

The gas turbine has the potential for power production at the highest possible efficiency. The challenge is to ensure that gas turbines operate at the optimum efficiency so as to use the least fuel and produce minimum emissions. A key component to meeting this challenge is the turbine. Turbine performance, both aerodynamics and heat transfer, is one of the barrier advanced gas turbine development technologies. This is a result of the complex, highly three-dimensional and unsteady flow phenomena in the turbine. Improved turbine aerodynamic performance has been achieved with three-dimensional highly-loaded airfoil designs, accomplished utilizing Euler or Navier-Stokes Computational Fluid Dynamics (CFD) codes. These design codes consider steady flow through isolated blade rows. Thus they do not account for unsteady flow effects. However, unsteady flow effects have a significant impact on performance. Also, CFD codes predict the complete flow field. The experimental verification of these codes has traditionally been accomplished with point data - not corresponding plane field measurements. Thus, although advanced CFD predictions of the highly complex and three-dimensional turbine flow fields are available, corresponding data are not. To improve the design capability for high temperature turbines, a detailed understanding of the highly unsteady and three-dimensional flow through multi-stage turbines is necessary. Thus, unique data are required which quantify the unsteady three-dimensional flow through multi-stage turbine blade rows, including the effect of the film coolant flow. Also, as design CFD codes do not account for unsteady flow effects, the next logical challenge and the current thrust in CFD code development is multiple-stage analyses that account for the interactions between neighboring blade rows. Again, to verify and or direct the development of these advanced codes, complete three-dimensional unsteady flow field data are needed.

Fleeter, S.; Lawless, P.B. [Purdue Univ., West Lafayette, IN (United States). School of Mechanical Engineering

1995-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "radiant heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Thermal Performance Evaluation of Attic Radiant Barrier Systems Using the Large Scale Climate Simulator (LSCS)  

SciTech Connect

Application of radiant barriers and low-emittance surface coatings in residential building attics can significantly reduce conditioning loads from heat flow through attic floors. The roofing industry has been developing and using various radiant barrier systems and low-emittance surface coatings to increase energy efficiency in buildings; however, minimal data are available that quantifies the effectiveness of these technologies. This study evaluates performance of various attic radiant barrier systems under simulated summer daytime conditions and nighttime or low solar gain daytime winter conditions using the large scale climate simulator (LSCS). The four attic configurations that were evaluated are 1) no radiant barrier (control), 2) perforated low-e foil laminated oriented strand board (OSB) deck, 3) low-e foil stapled on rafters, and 4) liquid applied low-emittance coating on roof deck and rafters. All test attics used nominal RUS 13 h-ft2- F/Btu (RSI 2.29 m2-K/W) fiberglass batt insulation on attic floor. Results indicate that the three systems with radiant barriers had heat flows through the attic floor during summer daytime condition that were 33%, 50%, and 19% lower than the control, respectively.

Shrestha, Som S [ORNL] [ORNL; Miller, William A [ORNL] [ORNL; Desjarlais, Andre Omer [ORNL] [ORNL

2013-01-01T23:59:59.000Z

442

Experimental and theoretical studies of friction and heat transfer in rough passages  

SciTech Connect

This document discusses activities during this reporting period. A paper based on the results presented in the first final report (DOE/CE/90029-2) and entitled The Role of Transition in Determining Friction and Heat Transfer in Smooth and Rough Passages'' was published in the October issue (Volume 33) of the International Journal of Heat and Mass Transfer. Beginning with the minimum objectives established at the outset of the period covered by this report, the general picture can be summed up as follows: detailed heat transfer and pressure drop (with and without heating) measurements with the smooth tube, fabrication of the eleven (enhanced tube) heat transfer test sections, tests with two of the three Hitachi tubes, and the construction of the liquid test facility were completed. In short, the minimum objectives were, for the most part, accomplished satisfactorily. 6 refs., 10 figs., 1 tab.

Obot, N.T.; Esen, E.B.

1990-12-01T23:59:59.000Z

443

On Water Flow in Hot Fractured Rock -- A Sensitivity Study on the Impact of Fracture-Matrix Heat Transfer  

E-Print Network (OSTI)

for both liquid and heat transfer processes. In order to beprocesses in hot fractured rock with ( 1) flow channeling in fractures, (2) interface reduction in F-M heat transfer,

Birkholzer, Jens T.; Zhang, Yingqi

2005-01-01T23:59:59.000Z

444

Using infrared thermography for the study of heat transfer through building envelope components  

Science Conference Proceedings (OSTI)

Heat transfer through building envelope components is typically characterized by one number, the conductance. Such a characterization is best suited for homogeneous samples since it does not quantify or illustrate spatial variations within a sample. However, the growing use of advanced wall and window insulations with existing framing materials has increased the importance of understanding spatial heat transfer effects within building envelope components. An infrared thermography laboratory has been established to provide detailed quantitative and qualitative information on the spatial heat transfer effects of building envelope materials. The use of this facility for more effective product development and more accurate product development and more accurate product characterization is discussed.

Arasteh, D.; Beck, F.; Griffith, B.; Acevedo-Ruiz, M. (Lawrence Berkeley Lab., CA (United States)); Byars, N. (California Polytechnic Univ., San Luis Obispo, CA (United States). Dept. of Engineering Technology)

1991-11-01T23:59:59.000Z

445

Influence of roughness on near-field heat transfer between two plates  

E-Print Network (OSTI)

The surface roughness correction to the near-field heat transfer between two rough bulk materials is discussed by using second-order perturbation theory. The results allow for estimating the impact of surface roughness to the heat transfer in recent experiments between two plates and between a microsphere and a plate (using the Derjaguin approximation). Furthermore, we show that the proximity approximation for describing rough surfaces is valid for distances much smaller than the correlation length of the surface roughness even if the heat transfer is dominated by the coupling of surface modes.

Svend-Age Biehs; Jean-Jacques Greffet

2011-03-11T23:59:59.000Z

446

Passive heat-transfer means for nuclear reactors. [LMFBR  

DOE Patents (OSTI)

An improved passive cooling arrangement is disclosed for maintaining adjacent or related components of a nuclear reactor within specified temperature differences. Specifically, heat pipes are operatively interposed between the components, with the vaporizing section of the heat pipe proximate the hot component operable to cool it and the primary condensing section of the heat pipe proximate the other and cooler component operable to heat it. Each heat pipe further has a secondary condensing section that is located outwardly beyond the reactor confinement and in a secondary heat sink, such as air ambient the containment, that is cooler than the other reactor component. By having many such heat pipes, an emergency passive cooling system is defined that is operative without electrical power.

Burelbach, J.P.

1982-06-10T23:59:59.000Z

447

A unified numerical framework model for simulating flow, transport, and heat transfer in porous and fractured media  

E-Print Network (OSTI)

fluid flow, multicomponent transport, and heat transfer in porous and fractured media,fluid flow, solute transport, and heat transfer occur in porous and fractured media.fluid flow, mass transport, and heat-transfer processes through porous and fractured media.

Wu, Yu-Shu

2004-01-01T23:59:59.000Z

448

Dependency of Heat Transfer Rate on the Brinkman Number in Microchannels  

E-Print Network (OSTI)

Heat generation from electronics increases with the advent of high-density integrated circuit technology. To come up with the heat generation, microscale cooling has been thought as a promising technology. Prediction of heat transfer rate is crucial in design of microscale cooling device but is not clearly understood yet. This work proposes a new correlation between heat transfer rate and Brinkman number which is nondimensional number of viscosity, flow velocity and temperature. It is expected that the equation proposed by this work can be useful to design microchannel cooling device.

H. S. Park

2008-01-07T23:59:59.000Z

449

IntroductiontoProcessEngineering(PTG) 5. Heat transfer  

E-Print Network (OSTI)

/x, T/y, T/z), Fourier's Law gives (for constant ) for the heat flux Q" = - T · The temperature field (T)dT )/(x2-x1) · For example, with (T)=0·(1+T), the heat flux Q" for T=T0 @ x=0 and T=T1 @ x be interpreted as a general physical law of the type: flow , heat, current = driving force / resistance; current

Zevenhoven, Ron

450

Radiant energy collection and conversion apparatus and method  

SciTech Connect

The apparatus for collecting radiant energy and converting same to alternate energy form includes a housing having an interior space and a radiation transparent window allowing, for example, solar radiation to be received in the interior space of the housing. Means are provided for passing a stream of fluid past said window and for injecting radiation absorbent particles in said fluid stream. The particles absorb the radiation and because of their very large surface area, quickly release the heat to the surrounding fluid stream. The fluid stream particle mixture is heated until the particles vaporize. The fluid stream is then allowed to expand in, for example, a gas turbine to produce mechanical energy. In an aspect of the present invention properly sized particles need not be vaporized prior to the entrance of the fluid stream into the turbine, as the particles will not damage the turbine blades. In yet another aspect of the invention, conventional fuel injectors are provided to inject fuel into the fluid stream to maintain the proper temperature and pressure of the fluid stream should the source of radiant energy be interrupted. In yet another aspect of the invention, an apparatus is provided which includes means for providing a hot fluid stream having hot particles disbursed therein which can radiate energy, means for providing a cooler fluid stream having cooler particles disbursed therein, which particles can absorb radiant energy and means for passing the hot fluid stream adjacent the cooler fluid stream to warm the cooler fluid and cooler particles by the radiation from the hot fluid and hot particles.

Hunt, Arlon J. (Oakland, CA)

1982-01-01T23:59:59.000Z

451

Heat transfer characteristics of a fluidized bed : stirling engine system.  

E-Print Network (OSTI)

??A fluidized bed combustion (FBC) system was designed to provide heat energy to the head of a Stirling cycle engine. Preliminary testing with a simulated… (more)

Anzalone, Thomas M.

1989-01-01T23:59:59.000Z

452

Investigation of Heat Transfer Conditions in a Reverberatory Melting ...  

Science Conference Proceedings (OSTI)

The model comprises different physical phenomenon as gas f low, chemical reactions, i.e. combustion, conduction, radiation and latent heat release in the metal.

453

Experimental study on condensation heat transfer of steam on vertical titanium plates with different surface energies  

Science Conference Proceedings (OSTI)

Visual experiments were employed to investigate heat transfer characteristics of steam on vertical titanium plates with/without surface modifications for different surface energies. Stable dropwise condensation and filmwise condensation were achieved on two surface modification titanium plates, respectively. Dropwise and rivulet filmwise co-existing condensation form of steam was observed on unmodified titanium surfaces. With increase in the surface subcooling, the ratio of area ({eta}) covered by drops decreased and departure diameter of droplets increased, resulting in a decrease in condensation heat transfer coefficient. Condensation heat transfer coefficient decreased sharply with the values of {eta} decreasing when the fraction of the surface area covered by drops was greater than that covered by rivulets. Otherwise, the value of {eta} had little effect on the heat transfer performance. Based on the experimental phenomena observed, the heat flux through the surface was proposed to express as the sum of the heat flux through the dropwise region and rivulet filmwise region. The heat flux through the whole surface was the weighted mean value of the two regions mentioned above. The model presented explains the gradual change of heat transfer coefficient for transition condensation with the ratio of area covered by drops. The simulation results agreed well with the present experimental data when the subcooling temperature is lower than 10 C. (author)

Baojin, Qi; Li, Zhang; Hong, Xu; Yan, Sun [State-Key Laboratory of Chemical Engineering, School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237 (China)

2011-01-15T23:59:59.000Z

454

Aerodynamic Losses and Heat Transfer in a Blade Cascade with 3-D Endwall Contouring  

NLE Websites -- All DOE Office Websites (Extended Search)

Aerodynamic Losses and Heat Transfer in a Aerodynamic Losses and Heat Transfer in a Aerodynamic Losses and Heat Transfer in a Aerodynamic Losses and Heat Transfer in a Blade Cascade with 3 Blade Cascade with 3 - - D D Endwall Endwall Contouring Contouring Principal Investigator Principal Investigator Sumanta Acharya, Professor Sumanta Acharya, Professor Louisiana State University, Baton Rouge, Louisiana Louisiana State University, Baton Rouge, Louisiana Collaborators Collaborators Gazi Mahmood, Ph.D., Research Asqociate Gazi Mahmood, Ph.D., Research Asqociate Arun Saha, Ph.D., Research Associate Arun Saha, Ph.D., Research Associate Ross Gustafson, M.S. student Ross Gustafson, M.S. student SCIES Project 02 SCIES Project 02 - - 01 01 - - SR098 SR098 DOE COOPERATIVE AGREEMENT DE DOE COOPERATIVE AGREEMENT DE - - FC26 FC26 - - 02NT41431 02NT41431 Tom J. George, Program Manager, DOE/NETL

455

Analysis of Chemically Reacting Gas Flow and Heat Transfer in Methane Reforming Processes  

Science Conference Proceedings (OSTI)

This paper presents simulation and analysis of gas flow and heat transfer affected by chemical reactions relating to steam reforming of methane in a compact reformer. The reformer conditions such as the combined thermal boundary conditions on solid walls, ...

Guogang Yang; Danting Yue; Xinrong Lv; Jinliang Yuan

2009-10-01T23:59:59.000Z

456

HEAT AND MASS TRANSFER IN A FAULT-CONTROLLED GEOTHERMAL RESERVOIR CHARGED AT CONSTANT PRESSURE  

E-Print Network (OSTI)

1975. Heat Transfer in Geothermal Systems, 11 in Advances inHydrothermal Systems, Geothermal Resources (eds. L. RybackI. G. , The Simulation of Geothermal Systems with a Simple

Goyal, K.P.

2013-01-01T23:59:59.000Z

457

Estimating Heat and Mass Transfer Processes in Green Roof Systems: Current Modeling Capabilities and Limitations (Presentation)  

Science Conference Proceedings (OSTI)

This presentation discusses estimating heat and mass transfer processes in green roof systems: current modeling capabilities and limitations. Green roofs are 'specialized roofing systems that support vegetation growth on rooftops.'

Tabares Velasco, P. C.

2011-04-01T23:59:59.000Z

458

Anomalous Near-Field Heat Transfer between a Cylinder and a Perforated Surface  

E-Print Network (OSTI)

We predict that the near-field radiative heat-transfer rate between a cylinder and a perforated surface depends nonmonotonically on their separation. This anomalous behavior, which arises due to evanescent-wave effects, ...

Rodriguez-Wong, Alejandro

459

Fluctuating-surface-current formulation of radiative heat transfer for arbitrary geometries  

E-Print Network (OSTI)

We describe a fluctuating-surface-current formulation of radiative heat transfer, applicable to arbitrary geometries in both the near and far field, that directly exploits efficient and sophisticated techniques from the ...

Rodriguez, Alejandro W.

460

Mechanism and behavior of nucleate boiling heat transfer to the alkalai liquid metals  

E-Print Network (OSTI)

A model of boiling heat transfer to the alkali liquid metals is postulated from an examination of the events and phases of the nucleate boiling cycle. The model includes the important effect of microlayer evaporation which ...

Deane, Charles William

1969-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "radiant heat transfer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Analysis of Sensitivities and Error Propagation in Heat and Mass Transfer of Spheroidal Hailstones Using Spreadsheets  

Science Conference Proceedings (OSTI)

In conformity with experimental results the heat transfer of gyrating spherical hailstones is divided into two parts. One takes place over a normally wet but supercooled equatorial region of limited roughness, whiles the other occurs over a rough,...

Roland List

1989-10-01T23:59:59.000Z

462

Numerical modeling of pool spreading, heat transfer and evaporation in liquefied natural gas (LNG).  

E-Print Network (OSTI)

?? This master's thesis is a continuation of previous theses written at ComputIT AS. It treats heat transfer to LNG pools boiling on water through… (more)

Myrmo, Øystein

2011-01-01T23:59:59.000Z

463

A technique to measure turbulent free convective heat transfer in a vertical tall cavity.  

E-Print Network (OSTI)

??A time-average technique was developed to measure the unsteady and turbulent free convection heat transfer in tall vertical enclosure using a Mach-Zehnder interferometer. The method… (more)

Poulad, Mohammad Ebrahim

2009-01-01T23:59:59.000Z

464

Experimental Study of Heat Transfer and Flow Characteristics for a New Type of Air Heater  

E-Print Network (OSTI)

A new type air heater was developed, and an experimental set-up was built to analyze its characteristics. Within the Reynolds number from 2000 to 15000, the integrated characteristics in air heater channels with and without holed baffles have been studied experimentally. The experimental results show that the average Nu number increases greatly but the friction factor increases only slightly with the Re number. The Webb performance evaluation criterion has been adopted for analysis purposes. It is found that the integrated characteristics of heat transfer and flow friction increase with the hole's diameter at the same hole density (which is equal to the ratio of the hole's total area to the baffle's area), and the heat transfer rate increases with the hole density at the same hole diameter. The C type baffle has the best performance at the same heat transfer surface area and fan power consumption; its heat transfer rate improves about 44 to 69 percent.

Zheng, H.; Fan, X.; Li, A.

2006-01-01T23:59:59.000Z

465

1-2-3D Heat Transfer Simulation Software for Buildings by Physibel  

NLE Websites -- All DOE Office Websites (Extended Search)

1-2-3D Heat Transfer Simulation Software for Buildings by Physibel Speaker(s): Piet Standaert Date: August 8, 2002 - 12:00pm Location: Bldg. 90 Seminar HostPoint of Contact:...

466

Radiative Heat Transfer Analysis within Three-Dimensional Clouds Subjected to Solar and Sky Irradiation  

Science Conference Proceedings (OSTI)

A three-dimensional radiative heat transfer analysis of an arbitrary-shaped modeled cloud subjected to solar and sky irradiation has been performed. The Radiation Element Method by Ray Emission Model (REM2) was used for numerical simulation. ...

Toru Nishikawa; Shigenao Maruyama; Seigo Sakai

2004-12-01T23:59:59.000Z

467

Wetting and phase-change phenomena on micro/nanostructures for enhanced heat transfer  

E-Print Network (OSTI)

Micro/nanostructures have been extensively studied to amplify the intrinsic wettability of materials to create superhydrophilic or superhydrophobic surfaces. Such extreme wetting properties can influence the heat transfer ...

Xiao, Rong, Ph. D. Massachusetts Institute of Technology

2013-01-01T23:59:59.000Z

468

Forced-convection surface-boiling heat transfer and burnout in tubes of small diameters  

E-Print Network (OSTI)

A basic heat-transfer apparatus was designed and constructed for the study of forced-convection boiling in small channels. The various regions of forced-convection surface boiling were studied experimentally and analytically. ...

Bergles A. E.

1962-01-01T23:59:59.000Z

469

Heat and mass transfer in a falling film absorber of ammonia-water absorption systems  

SciTech Connect

For ammonia-water generator-absorber heat exchanger (GAX) systems to work at high coefficient of performance, the heat and mass transfer components have to operate at optimum performance within a narrow range of conditions for the recovery of internal energy. In the present work, an analysis is performed to study the absorption process of an ammonia-water vapor mixture by an aqueous solution of ammonia in a falling film absorber. The combined heat and mass transfer processes involved are analyzed through an integral formulation of the continuity, momentum, energy, and diffusion equations. The effects of vapor flow direction relative to the solution, cooling ability, ammonia concentration of solution and vapor, and interfacial momentum and heat transfer rate on absorption processes are investigated. The characteristics of the absorption process are found to be governed by the relative significance of the mass transfer resistance and the driving forces between the solution film and the vapor mixture.

Kim, B. [Hongik Univ., Seoul (Korea, Republic of). Dept. of Mechanical Engineering

1998-07-01T23:59:59.000Z

470

The influence of return bends on the downstream pressure drop and condensation heat transfer in tubes  

E-Print Network (OSTI)

The influence of return bends on the downstream pressure drop and heat transfer coefficient of condensing refrigerant R-12 was studied experimentally. Flow patterns in glass return bends of 1/2 to 1 in. radius and 0.315 ...

Traviss, Donald P.

1971-01-01T23:59:59.000Z

471

Some aspects of the computer simulation of conduction heat transfer and phase change processes  

DOE Green Energy (OSTI)

Various aspects of phase change processes in materials are discussd including computer modeling, validation of results and sensitivity. In addition, the possible incorporation of cognitive activities in computational heat transfer is examined.

Solomon, A. D.

1982-04-01T23:59:59.000Z

472

Heat Transfer from Rotating Blade Platforms with and without Film Cooling  

NLE Websites -- All DOE Office Websites (Extended Search)

Transfer from Rotating Blade Transfer from Rotating Blade Platforms with and without Film Cooling J.C. Han and M.T. Schobeiri SCIES Project 03-01-SR113 DOE COOPERATIVE AGREEMENT DE-FC26-02NT41431 Texas A&M University Tom J. George, Program Manager, DOE/NETL Richard Wenglarz, Manager of Research, SCIES Project Awarded 07/01/2003 (36 Month Duration) $461,024 Total Contract Value ($361,024 DOE) Turbine Heat Transfer Laboratory Texas A&M University SR 113 - 10-2005 - JCHan Gas Turbine Needs Need Detailed Heat Transfer Data on Rotating Blade Platforms Improve Current Rotor Blade Cooling Schemes Provide Options for New Rotor Blade Cooling Designs Need Accurate and Efficient CFD Codes to Improve Flow and Heat Transfer Predictions and Guide Rotor Blade Cooling Designs Improved Turbine Power Efficiency by Increasing Turbine

473

Time-resolved ellipsometry for studies of heat transfer at liquid/solid and gas/solid interfaces  

E-Print Network (OSTI)

partly controlled by the rate of heat transfer across the interface. Heat moving from the metal film is heated by 10 K using an ultrafast optical pump pulse; the subsequent changes of the phase differenceTime-resolved ellipsometry for studies of heat transfer at liquid/solid and gas/solid interfaces

Granick, Steve

474

Forced convection heat transfer in the transition region between laminar and turbulent flow for a vertical circular tube  

Science Conference Proceedings (OSTI)

In this study, first results of the heat transfer characteristic of a vertical double tube heat exchanger were determined. The heat exchanger was operated under cocurrent-flow conditions. The Reynolds-number was varied in the transition region between ... Keywords: circular tube, forced convection, heat transfer, transition region

D. Huber; H. Walter

2010-07-01T23:59:59.000Z

475

Heat transfer in porous media with fluid phase changes  

DOE Green Energy (OSTI)

A one-dimensional experimental apparatus was built to study the heat pipe phenomenon. Basically, it consists of a 25 cm long, 2.5 cm I.D. Lexane tube packed with Ottawa sand. The two ends of the tube were subjected to different tempratures, i.e., one above the boiling temperature and the other below. The tube was well insulated so that a uniform one-dimensional heat flux could pass through the sand pack. Presence of the heat pipe phenomenon was confirmed by the temperature and saturation profiles of the sand pack at the final steady state condition. A one-dimensional steady state theory to describe the experiment has been developed which shows the functional dependence of the heat pipe phenomenon on liquid saturation gradient, capillary pressure, permeability, fluid viscosity, latent heat, heat flux and gravity. Influence of the heat pipe phenomenon on wellbore heat losses was studied by use of a two-phase two-dimensional cylindrical coordinate computer model.

Su, H.J.

1981-06-01T23:59:59.000Z

476

Effect of infrared transparency on the heat transfer through windows: a clarification of the greenhouse effect  

SciTech Connect

The various radiative, convective, and conductive components of the net heat transfer are calculated and illustrated for various infrared transparencies of covers such as would be used in architectural, greenhouse, or solar collector windows. It is shown that in the limiting cases of infrared opacity and infrared transparency the relative contributions of the three modes of heat transfer are altered, but all contribute significantly. The radiation shielding arguments pertain to the analogous greenhouse effect in the atmosphere.

Silverstein, S.D.

1976-07-16T23:59:59.000Z

477

Global existence result for phase transformations with heat transfer in shape memory alloys  

E-Print Network (OSTI)

We consider three-dimensional models for rate-independent processes describing materials undergoing phase transformations with heat transfer. The problem is formulated within the framework of generalized standard solids by the coupling of the momentum equilibrium equation and the flow rule with the heat transfer equation. Under appropriate regularity assumptions on the initial data, we prove the existence a global solution for this thermodynamically consistent system, by using a fixed-point argument combined with global energy estimates.

Paoli, Laetitia

2011-01-01T23:59:59.000Z

478

Development of a carburizing and quenching simulation tool: Determination of heat transfer boundary conditions in salt  

Science Conference Proceedings (OSTI)

In the numerical simulation of the quenching of steel parts, it is desirable to limit the thermal problem to one of conduction in the solid part, with Newtonian cooling on the surface. This avoids the solution of highly transient, non-Boussinesq conjugate heat transfer problems which often involve mixed convection. Of course, the heat transfer