Numerical performance analysis of a solar collector enhanced with a top–down rectangular corrugated design, porous metal foam, and a parabolic reflector

The study investigates performance enhancement in a flat-plate downward single rectangular corrugated solar collector, focusing on direct absorption efficiency improvements through porous insertions. This collector configuration incorporates a rectangular corrugated block positioned near the midpoint of the upper absorber plate. The dimensions of this corrugated block, especially its length and height, are systematically varied near the upper region of the absorber. Within this collector design, thermal heat transfer is facilitated from a parabolic trough collector directly to the heat source reflector, subsequently directing energy to the lower absorber plate. This parametric study aims to identify the optimal configuration and insertion pattern for the corrugated block, with variations in block height (ranging from 0 to H in increments of 0.01) and length(from 0 to L in increments of 0.05). Furthermore, the permeability of the porous channel permeability varies between Da = 10−5–10−1, providing additional control over the thermal dynamics. The analysis utilizes COMSOL Multiphysics 5.6 with an adapted steady-state thermal transport code incorporating the extended Darcy–Brinkman–Forchheimer model to simulate the porous medium behavior. Numerical findings indicate a marked improvement in overall thermal performance through the strategic positioning of the corrugated block, enhancing heat transfer by inducing thermal mixing near the absorber plate. Results reveal that optimized thermal contact is achieved as flow is directed preferentially toward the lower absorber plate, facilitating superior interaction with the working fluid. The highest potential performance is observed with minimal corrugated block height and maximal length near the upper absorber plate. The thermal performance of a flat-plate downward single rectangular corrugated solar collector is enhanced using porous insertions and optimized corrugated block geometry. Simulations incorporating the extended Darcy–Brinkman–Forchheimer model show that minimal block height and maximal length near the upper absorber improve thermal mixing and heat transfer efficiency.