scholarly journals Numerical study of natural convection in an inclined enclosure: application to flat plate solar collectors

2017 ◽  
Vol 4 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Charaf-Eddine Bensaci ◽  
Adnane Labed ◽  
Miloud Zellouf ◽  
Abdelhafid Moummi
Keyword(s):  
Natural Convection ◽  
Flat Plate ◽  
Numerical Study ◽  
Solar Collectors ◽  
Inclined Enclosure

Natural Convection in Collector Cavities With an Isoflux Absorber Plate

1983 ◽  
Vol 105 (1) ◽  
pp. 19-22 ◽  
Author(s):  
W. M. M. Schinkel ◽  
C. J. Hoogendoorn
Keyword(s):  
Heat Transfer ◽  
Boundary Condition ◽  
Natural Convection ◽  
Solar Collector ◽  
Numerical Study ◽  
Cold Wall ◽  
Solar Collectors ◽  
Absorber Plate ◽  
Hot Plate ◽  
Expected Values

The boundary condition at the hot absorber plate in a solar collector will influence the natural convection in the enclosure. For the isoflux boundary condition and an isothermal cold wall an experimental and numerical study has been made for Ra numbers from 105 to 107 and inclinations from 20 to 90 deg with the horizontal. For vertical enclosures the heat transfer by natural convection was about 19 percent above that for an isothermal hot plate. This decreases with angle of inclination, to 9 percent at 20 deg. For solar collectors it means that for cases where the absorber plate is not isothermal the convective losses can be about 10 percent above the usually expected values.

scholarly journals Optimization of Inclination Angle of Cavity and Characteristics of Attached Fins on the Absorber for Performance Enhancement of Solar Collectors

2021 ◽  
Vol 12 (3) ◽  
pp. 216-221
Author(s):  
A. D. Gupta ◽  
◽  
Ashish Gupta ◽  
P. K. Mishra ◽  
Yashi Gupta ◽  
...  
Keyword(s):  
Natural Convection ◽  
Free Convection ◽  
Flat Plate ◽  
Heat Loss ◽  
Inclination Angle ◽  
Convection Heat ◽  
Solar Collectors ◽  
Aspect Ratios ◽  
Simpler Algorithm ◽  
Flat Plate Collector

This research investigation was undertaken in ANDUAT, Kumarganj, Ayodhya, Uttar Pradesh, India to study the numerical optimization of natural convection heat suppression in a solar flat plate collector with straight fins. Optimal characteristics of an array of thin fins attached on the absorber plat were obtained by Particle Swarm Optimization algorithm (PSOA). Free convection considered dominant in the cavity. Governing equations contained continuity; momentum and energy are discretized by finite volume method. The medium is considered incompressible, whose free convection is dominant and Boussinesq approximation is applied. A simplified model of real systems is applied with free convection. Free convection problem is solved by SIMPLER algorithm. Two confined cavities with aspect ratios 30 and 60 are considered as flat plate solar collectors. The results indicate that significant reduction on the free convection heat loss can be obtained from solar flat plate collector by using plate fins, and an optimal plate fins configuration exit for minimal natural convection heat loss for a given range of Rayleigh number. Reduction of up to a maximum of 25% at 0 inclination angle was observed in aspect ratio 30. Results showed PSOA is able to obtain characteristics of attached adiabatic fins on the absorber plate also it can obtain optimal inclination angle of cavity to decrease heat losses from solar collectors. The results obtained provide a novel approach for improving design of flat plate solar collectors for optimal performance.

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