Impact of a new envelope winglet vortex generator on engine power and thermoelectric waste heat recovery

Abstract

In this study, a new envelope winglet vortex generator is numerically analyzed and installed on the hot side of the thermoelectric generator (TEG) exhaust heat exchanger. Experiments for the TEG-based waste heat recovery (WHR) system integrated with engine exhaust have identified the best design configuration for the envelope winglet vortex generator in terms of pitch/channel height ratio (P/H) and tilt angles (θ). The system's feasibility has been proven by contrasting the current thermoelectric-based WHR with conventional alternator technology. Numerical research showed that the more significant flow rates in longitudinal envelope winglet VGs resulted in a larger radius. The envelope winglet profile has a sizable impact on the performance of the innovative TEG system with a vortex generator in the exhaust heat exchanger. The current analysis indicates that the exhaust heat exchanger arrangement with a pitch/channel height ratio (P/H) of 3 and a tilt angle (θ) of 60° produces the system's best power output. Maximum power output and maximum net power output at engine load L3 are shown at θ = 60° and 105 and 56.86% higher than those of the smooth channel, respectively. However, the largest power out and net power output increases are determined to be 68.08 and 42.28%, respectively, for P/H = 3. The recommended envelope winglet Vortex Generators (VGs) in engine operating mode L3 can raise brake-specific fuel consumption (BSFC) by up to 0.82%. The engine would operate at this mode's lowest fuel consumption and emissions. © 2023, Akadémiai Kiadó, Budapest, Hungary.