Computational study of heat transfer in solar collectors with different radiative flux models

Kuharat, S; Beg, OA; Kadir, A; Shamshuddin, M

Abstract

2D steady incompressible laminar Newtonian viscous convection-radiative heat transfer in a rectangular solar collector geometry is considered. The ANSYS FLUENT finite volume code (version 17.2) is employed to simulate the thermo-fluid characteristics. Extensive details of computational methodology are given to provide engineers with a framework for simulating radiative-convection in enclosures. Mesh-independence tests and validation are conducted. The influence of aspect ratio, Prandtl number (Pr), Rayleigh number (Ra) and radiative flux model on temperature, isotherms, velocity, pressure is evaluated and visualized in colour plots. Additionally, local convective heat flux is computed, and solutions are compared with the MAC solver for various buoyancy effects achieving excellent agreement. The P1 model is shown to better predict the actual influence of solar radiative flux on thermal fluid behaviour compared with the limited Rosseland model. With increasing Ra, the hot zone emanating from the base of the collector is found to penetrate deeper into the collector and rises symmetrically dividing into two vortex regions with very high buoyancy effect. With increasing Pr there is a progressive incursion of the hot zone at the solar collector base higher into the solar collector space and simultaneously a greater asymmetric behaviour of the dual isothermal zones.

Citation

Kuharat, S., Beg, O., Kadir, A., & Shamshuddin, M. (2019). Computational study of heat transfer in solar collectors with different radiative flux models. Heat Transfer - Asian Research, 48(3), 1002-1031. https://doi.org/10.1002/htj.21418

• Journal Article Type: Article
• Acceptance Date: Dec 26, 2018
• Online Publication Date: Jan 12, 2019
• Publication Date: Jan 12, 2019
• Deposit Date: Jan 7, 2019
• Publicly Available Date: Jan 12, 2020
• Journal: Heat Transfer - Asian Research
• Print ISSN: 1099-2871
• Electronic ISSN: 1523-1496
• Publisher: Wiley
• Volume: 48
• Issue: 3
• Pages: 1002-1031
• DOI: https://doi.org/10.1002/htj.21418
• Publisher URL: https://doi.org/10.1002/htj.21418
• Related Public URLs: https://onlinelibrary.wiley.com/journal/15231496