Maximizing thermohydraulic performance of solar air heaters with staggered v-ribbed surfaces using metaheuristic algorithms

Abstract

This study aimed to determine the influence of roughness parameters on the thermohydraulic performance (THP) of a solar air heater with a roughened surface and a V-shaped rib element with staggered twists. In order to get more exact and accurate findings with fewer experiment trials, cost, and time-saving, morphological and operational parameters are adjusted by designing experiments using response surface methodology (RSM) and a metaheuristic technique such as the teacher-learning-based optimization (TLBO) algorithm. The development of a regression model for estimating THP in terms of specified roughness and flow parameters has been provided. The final optimization result demonstrates that TLBO outperforms RSM in terms of performance. Previously, thermal measurement technique was made through thermocouples, which were unable to give the actual dispersal of thermal mapping, but this research paper investigates the effect of rib elements on the thermal performance, with their varied parameters assessed with the unique measurement technique of liquid crystal thermography. Experimentally determined values at P/e = 9, d/e = 4, S/e = 6.15, and Re = 18,555 provide a maximum THP of 2.69. With a mean bias error of 0.015, the maximal THP value derived by the TLBO algorithm displays excellent agreement with the testing data. The analysis of variance reveals that Re has the greatest influence on THP, with a percentile contribution of 63.63%, while the contributions for other parameters are 39.81%, 37.61%, and 56.11% for the optimal roughness values, respectively.