A review of CFD methodology used in literature for predicting thermo-hydraulic performance of a roughened solar air heater

A solar air heater is experimentally investigated by many researchers to study the effect of operating and geometrical parameters on heat transfer and fluid flow characteristics. The availability of highly advanced computer hardware and development in numerical methods, encouraging the future researchers to carry out the simulations of solar air heater using various roughness geometries with different ranges of operating and geometrical parameters. CFD is emerging as an efficient tool to detect the optimum configuration of rib for its maximum thermo hydraulic performance before carrying out actual experimentation. This article discusses different approaches used to investigate the thermal performance of solar air heater. The computational approach, i.e. CFD methodology is discussed using the reference of commercial CFD software ANSYS FLUENT. The main aim of the article is to present a detailed review of the literature that deals with the application of CFD in the design of solar air heater. The paper has a concise summary of each reviewed article in the form of, type of computational domain (2D/3D), turbulence model used, type of CFD commercial software used, range of operating and geometrical parameters and best results obtained from CFD. The article also tabulated the optimum values of relative roughness pitch (P/e) and relative roughness height (e/D) for maximum heat transfer enhancement in roughened solar air heater duct.