Automotive Exhaust Thermoelectric Generator Unit Integrated to Exhaust Noise Muffler: Heat Recovery and Noise Attenuation Simulations

Abstract

This study aims at energy harvesting mufflers that utilize thermoelectric generators (TEG) to convert waste heat from the engine exhaust into electricity and simultaneously reduce engine noise. The recovered electricity can be used to power the auxiliary units in the automobile and can effectively improve the overall efficiency of the system. In this study, an automotive exhaust thermoelectric generator (AETEG) unit is fabricated to extract the waste exhaust heat from the engine. To further enhance the performance of AETEG unit, changes in the internal geometry of the unit are proposed, and a systematic computational study is carried. Investigation results indicate that transformations in the internal geometry enhance the heat transfer rate due to lower flow stratification and induced turbulence. This shows increasing potential for higher electricity generation. However, an increase in backpressure due to flow obstruction remains a problem with increasing baffle count. The internal geometry with six baffles gave the best thermal performance with backpressure within acceptable limits for the studied cases. Additionally, that AETEG unit serves as a noise muffler and attenuates the exhaust noise by 53 dBA.