Nidhul, K.Kumar, S.Yadav, A.Anish, S.2026-02-052020Energy, 2020, 200, , pp. -3605442https://doi.org/10.1016/j.energy.2020.117448https://idr.nitk.ac.in/handle/123456789/23874Computational fluid dynamics (CFD) and exergy analysis are conducted to investigate the impact of secondary flow produced by V-ribs on the overall performance of a triangular solar air heater (SAH) duct. For a fixed relative rib pitch (R<inf>p</inf> = 10) and relative rib height (R<inf>h</inf> = 0.05), the effect of rib inclination (?) is studied using CFD technique for varying Reynolds number (5000 ? Re ? 20000). Based on the CFD simulation results, empirical correlations capable of predicting Nu and f with an absolute variance of 8.7%, and 4.7%, respectively, are developed. Employing these correlations, exergetic performance analysis is carried out. Maximum effectiveness parameter (?) of 2.01 is obtained for ? = 45° at Re = 7500. The exergy analysis reveals that the entropy generated is lower for the ribbed triangular duct compared to the smooth duct with maximum enhancement in exergetic efficiency (?<inf>ex</inf>) as 23% for ? = 45°. The study is extended for the rectangular duct to compare the performance with the ribbed triangular duct SAH (? = 45°). Results show that ribbed triangular duct SAH (? = 45°) is superior over various configurations of the ribbed rectangular duct SAH at higher mass flow rates. © 2020 Elsevier LtdAirAir preheatersComputational fluid dynamicsExergyHeating equipmentReynolds numberSolar equipmentSolar heatingCFD simulationsEmpirical correlationsExergetic efficiencyExergetic performanceExergy AnalysisRectangular ductsSolar air heaterThermo-hydraulic performanceDuctscomputational fluid dynamicsdetection methodequipmentexergyperformance assessmentphotovoltaic systemsimulation