Transpired solar air heaters. Volume 3. Effect of wall suction on laminar entrance flow with application to solar air heaters. Final report
Numerical solutions are obtained for hydrodynamically and thermally developing steady-state laminar flow in a long rectangular cavity with uniform suction and one wall and uniform temperature or heat flux independently prescribed at each wall. Fully developed velocity profiles obtained for Re/sub w/ = 4.0 and 10.0 show excellent agreement with the similarity solutions of previous investigators. For the temperature field, building-block solutions and linear superposition allow the construction of the solution for any case of uniform boundary conditions. Application of the results to the analysis and design of transpired solar air heaters is discussed. Collection efficiencies for several solar air heaters are predicted by performing a system analysis. Result of the system analysis obtained through computer simulation are in good agreement with experimental data; the maximum deviations are a 2% overprediction and a 3% underprediction in instantaneous efficiency. Five selective-black-metal-plate experimental solar air heaters with and without transpiration were designed, fabricated, and tested to compare their technical merits and to prove how well the theoretical results and system analysis predict performance of actual solar collectors. Based on the test results, the configuration with slotted absorber plate (the working fluid transpires through the slots) is the best solar air heater in terms of collector efficiency and pressure drop among the five configurations. Based on the knowledge obtained from the theoretical results, system analysis, and experimental results, discussion of the design of a full-scale selective-black-metal-plate solar air heater with transpiration through slots is presented. Discussed are: (1) the number of teflon films for cover glazing assembly; (2) the spacing between glazing elements; (3) the spacing between the absorber plate and the inner glazing; and (4) the design of inlet and outlet manifolds.
- Research Organization:
- California Univ., Los Angeles (USA). School of Engineering and Applied Science
- DOE Contract Number:
- FG04-77CS34088
- OSTI ID:
- 6141614
- Report Number(s):
- UCLA-ENG-8078; ON: DE83012092
- Resource Relation:
- Other Information: Portions are illegible in microfiche products. Thesis
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SOLAR AIR HEATERS
LAMINAR FLOW
BOUNDARY CONDITIONS
COMPUTERIZED SIMULATION
DESIGN
EQUATIONS OF MOTION
FABRICATION
FLAT PLATE COLLECTORS
HEAT TRANSFER
NUMERICAL SOLUTION
POROUS MATERIALS
STEADY-STATE CONDITIONS
SYSTEMS ANALYSIS
TEMPERATURE DISTRIBUTION
TRANSPIRATION
VELOCITY
WALLS
AIR HEATERS
DIFFERENTIAL EQUATIONS
ENERGY TRANSFER
EQUATIONS
EQUIPMENT
FLUID FLOW
HEATERS
MATERIALS
PARTIAL DIFFERENTIAL EQUATIONS
SIMULATION
SOLAR COLLECTORS
SOLAR EQUIPMENT
141000* - Solar Collectors & Concentrators