Effect of pitch and angle of attack on thermal performance of new envelope and delta vortex generators for TEG: An experimental and numerical approach

Abstract

This study recommends a novel vortex generator (VG) inserted heat exchanger (HX) for internal heat transfer. Vortex generator geometry includes pitch ratio, envelope shape (M-shape), angle of attack, and delta wing (triangular form). VGs were placed in several array configurations with three pitch ratios to discover the ideal pitch ratio. Pressure loss, percentage change in Nusselt number, thermal enhancement factor, thermoelectric generator (TEG) power output, and cost-benefit ratio (CBR) were evaluated for HX with VG systems by experimentation and numerical modeling. The vortex generator in the best HX design won. Delta wing VGs had the highest TEG power and convective heat transfer coefficient. An envelope-shaped HX at 30o and a pitch of 4 reduces pressure loss. Delta form VG's maximum average heat transfer coefficient is 342.41 W/m2K at pitch 2 with a 60° angle of attack. VGs decreasing pressure required more power for the HX. HX installed with delta-shaped VGs reduced pressure the greatest. Pitch ratios 2, 3, and 4 experienced maximum pressure declines of 116.67%, 83.33%, and 73.34%. Delta winglet VGs at 45° showed 7.6%, 6.17%, and 46.16% higher thermal enhancement factor (TEF) than 30°, 60°, and 90o. Delta winglet VGs at 45° showed 7.6%, 6.17%, and 46.16% higher TEF than 30°, 60°, and 90° installed in HX. Numerical analysis showed that delta winglet vortex generators cause a higher reduction in pressure than envelope winglet VGs. Research shows the vortex generator TEG system generates more power than the internally flat HX. © 2023