skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: CFD simulation of simultaneous monotonic cooling and surface heat transfer coefficient

Abstract

The monotonic heating regime method for determination of thermal diffusivity is based on the analysis of an unsteady-state (stabilised) thermal process characterised by an independence of the space-time temperature distribution on initial conditions. At the first kind of the monotonic regime a sample of simple geometry is heated / cooled at constant ambient temperature. The determination of thermal diffusivity requires the determination rate of a temperature change and simultaneous determination of the first eigenvalue. According to a characteristic equation the first eigenvalue is a function of the Biot number defined by a surface heat transfer coefficient and thermal conductivity of an analysed material. Knowing the surface heat transfer coefficient and the first eigenvalue the thermal conductivity can be determined. The surface heat transport coefficient during the monotonic regime can be determined by the continuous measurement of long-wave radiation heat flow and the photoelectric measurement of the air refractive index gradient in a boundary layer. CFD simulation of the cooling process was carried out to analyse local convective and radiative heat transfer coefficients more in detail. Influence of ambient air flow was analysed. The obtained eigenvalues and corresponding surface heat transfer coefficient values enable to determine thermal conductivity of the analysedmore » specimen together with its thermal diffusivity during a monotonic heating regime.« less

Authors:
;  [1]
  1. Institute of Construction and Architecture, Slovak Academy of Sciences, Dubravska cesta 9, 845 03 Bratislava (Slovakia)
Publication Date:
OSTI Identifier:
22608488
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1752; Journal Issue: 1; Conference: THERMOPHYSICS 2016: 21. international meeting on thermophysics, Terchova (Slovakia), 12-14 Oct 2016; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; AIR FLOW; AMBIENT TEMPERATURE; BOUNDARY LAYERS; COOLING; EIGENVALUES; HEAT FLUX; HEAT TRANSFER; HEATING; LONG WAVE RADIATION; REFRACTIVE INDEX; SIMULATION; SPACE-TIME; SURFACES; TEMPERATURE DISTRIBUTION; THERMAL CONDUCTIVITY; THERMAL DIFFUSIVITY

Citation Formats

Mihálka, Peter, E-mail: usarmipe@savba.sk, and Matiašovský, Peter, E-mail: usarmat@savba.sk. CFD simulation of simultaneous monotonic cooling and surface heat transfer coefficient. United States: N. p., 2016. Web. doi:10.1063/1.4955251.
Mihálka, Peter, E-mail: usarmipe@savba.sk, & Matiašovský, Peter, E-mail: usarmat@savba.sk. CFD simulation of simultaneous monotonic cooling and surface heat transfer coefficient. United States. doi:10.1063/1.4955251.
Mihálka, Peter, E-mail: usarmipe@savba.sk, and Matiašovský, Peter, E-mail: usarmat@savba.sk. Thu . "CFD simulation of simultaneous monotonic cooling and surface heat transfer coefficient". United States. doi:10.1063/1.4955251.
@article{osti_22608488,
title = {CFD simulation of simultaneous monotonic cooling and surface heat transfer coefficient},
author = {Mihálka, Peter, E-mail: usarmipe@savba.sk and Matiašovský, Peter, E-mail: usarmat@savba.sk},
abstractNote = {The monotonic heating regime method for determination of thermal diffusivity is based on the analysis of an unsteady-state (stabilised) thermal process characterised by an independence of the space-time temperature distribution on initial conditions. At the first kind of the monotonic regime a sample of simple geometry is heated / cooled at constant ambient temperature. The determination of thermal diffusivity requires the determination rate of a temperature change and simultaneous determination of the first eigenvalue. According to a characteristic equation the first eigenvalue is a function of the Biot number defined by a surface heat transfer coefficient and thermal conductivity of an analysed material. Knowing the surface heat transfer coefficient and the first eigenvalue the thermal conductivity can be determined. The surface heat transport coefficient during the monotonic regime can be determined by the continuous measurement of long-wave radiation heat flow and the photoelectric measurement of the air refractive index gradient in a boundary layer. CFD simulation of the cooling process was carried out to analyse local convective and radiative heat transfer coefficients more in detail. Influence of ambient air flow was analysed. The obtained eigenvalues and corresponding surface heat transfer coefficient values enable to determine thermal conductivity of the analysed specimen together with its thermal diffusivity during a monotonic heating regime.},
doi = {10.1063/1.4955251},
journal = {AIP Conference Proceedings},
number = 1,
volume = 1752,
place = {United States},
year = {Thu Jul 07 00:00:00 EDT 2016},
month = {Thu Jul 07 00:00:00 EDT 2016}
}