Entropy-based multi-criteria decision optimization of dimpled solar air heater duct using WASPAS and MAIRCA models

The purpose of the current examination is to optimize the geometric parameters of dimple-shaped roughened solar air heater (DSRSAH), for which a hybrid multi-criteria decision-making (MCDM) approach has been developed. It balances the advantages of improved heat transfer (HT) with the drawbacks of higher frictional losses from artificial roughness on the absorber plate. To evaluate the performance of 27 experimental configurations of DSRSAH, the entropy-weighted WASPAS and MAIRCA models are utilised. Pitch ratio ($$\text{p}/e$$) varied from 10 to 20, relative roughness height ($$\text{e}/{D}_{h}$$) from 0.021 to 0.036 and arc angle ($$\alpha$$) from 45º-75º during analyses. For providing a comprehensive performance assessment, the evaluation criteria include the Nusselt number ($${Nu}_{DSR}$$), friction factor ($${f}_{DSR}$$), and thermohydraulic performance parameter ($${\eta}_{THPP}$$). In order to compare improvements in HT and pressure drop to a smooth duct, ratio $${Nu}_{DSR}/{Nu}_{SM}$$ and $${f}_{DSR}/{f}_{SM}$$ are used. Entropy approach is a strategy that enables the objective of assigning weights based on the dispersion of data. The configuration with highest effectiveness is $$\text{e}/{D}_{h}=0.036$$, $$\text{p}/e=10$$, and $$\alpha$$ = 60°. Furthermore, the reliability and robustness of the selected design is confirmed by sensitivity analysis.