Experimental investigation and optimization of dimple-roughened impinging jet solar air collector using a novel AHP-MABAC approach

Abstract

The effect of the flow and geometric parameters of a dimple-roughened absorber plate on the enactment of solar air collectors (SACs) with air-impinged jets was investigated in this study. The performance-defining criteria (PDCs) of a jet-impinged dimple-roughened SAC (JIDRSAC)-forced convection airflow system are significantly affected by variations in the system's control factors (CFs), such as the arc angle (α_aa) ranging from 30° to 75°, dimple pitch ratio (p_d/D_h) ranging from 0.269 to 1.08, and dimple height ratio (e_d/D_h) ranging from 0.016 to 0.0324. The constant parameters of the jet slot are a stream-wise pitch ratio (X_i/D_hd) is 1.079, a span-wise pitch ratio (Y_i/D_hd) is 1.619, and a jet diameter(D_i/D_hd) is 0.081. Based on the combined approach of the analytic hierarchy process and multi-attributive border approximation area comparison (AHP-MABAC), the Reynolds number (Re) = 15,000, α_aa = 60°, p_d/D_h = 0.27, and e_d/D_h = 0.027 depicted the best alternative (A-9) set among 16 alternatives to deliver the optimal performance of the JIDRSAC. The jet impingement pass compared to the smooth pass, the Nusselt number increased by 2.16-2.81, and friction factor increased by 3.35-5.95, and JIDRSAC was compared to the jet impingement pass, exhibiting an enhancement in Nusselt number and friction factor in the range of 0.55-0.80 and 0.05-0.15, respectively. In addition, sensitivity analysis is used to examine the ranking's stability and reliability in relation to the PDC weights.

Keywords: AHP-MABAC; Air impinged; Dimple roughness; Exergetic efficiency; Optimization; Solar air collector.