Parametric CFD study of Solar Air Heater having alternated upper and bottom absorber plates in turbulent flow

This work presents a CFD investigation of a Solar Air Heater that features alternating upper and bottom absorber plates to evaluate its thermal behavior and turbulent flow characteristics. Generally, the SAH exhibits low heat transfer characteristics and poor thermal efficiency in turbulent flow. The use of alternating upper and bottom absorber plates facing the turbulent flow would improve heat transfer by producing recirculation zones mainly over these heated plates. The Computational Fluid Dynamics software program, Ansys Fluent 15.0, along with the RNG k-ε turbulence model, was utilized in this analysis to solve the transport equations for turbulent kinetic energy and dissipation rate. The analysis encompassed several geometric and operating parameters, including the range of relative absorber plate length (lp/h) from 4.375 to 140, relative absorber plate height (h/H) ranging from 0.03 to 0.12, and Reynolds numbers varying between 3800 and 18000. The impact of these parameters on heat transfer improvement factors, including the Heat Transfer Amelioration Factor (HTAR), Friction Loss Amelioration Factor (FLAR), and Thermo-Hydraulic Efficiency Factor (THEF), was studied. The optimum computed THEF value was found to be 2.18 for (Lp/h) = 4.375, (h/H) = 0.12, and Re = 3,800