Hybrid entropy - TOPSIS approach for energy performance prioritization in a rectangular channel employing impinging air jets

Impinging air jets released against the heat transferring surface can transfer large amount of thermal energy between the surface and the fluid. The design parameters of a jet impingement device have to be optimized for maximum output from the system, taking into account the key performance defining criteria (ADCs). In the present study, the performance of impinging air jets in a rectangular channel has been studied experimentally based upon which the PDCs have been evaluated. Each performance criterion show a disparate trend in view of which it becomes essential to optimize the parameters based upon the output of the essential criteria. The combined Entropy and TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) method, a multi criterion decision making approach is applied for optimization of process parameters considering four different performance defining criteria simultaneously. Based upon entropy-TOPSIS approach, the jet diameter ratio, streamwise pitch ratio, spanwise pitch ratio and flow Reynolds number of 0.065, 0.435, 0.869 and 16000 respectively presents the best alternative set among all others to deliver the highest overall performance. Also, sensitivity analysis is carried out to study the stability and robustness of the ranking with respect to the weights of the PDCs. (C) 2017 Published by Elsevier Ltd.