Thermoelectric Waste Heat Recovery in a Concentric Tube Silencer for Automotive System

In this work, a concentric tube silencer is modeled and studied for its thermodynamic properties using time-dependent compressible computational fluid dynamics. The silencer is simultaneously studied for its capabilities to transfer heat to thermoelectric devices surrounding the silencer, as well as its ability to reduce noise. Two silencer geometries, one with round and the other with square cross-sections, are considered. Efforts have been conducted to recapture the heat from the exhaust for reuse within the automotive system. One such effort involved the ’modified silencing heat exchanger’ recently proposed to replace the muffler of automobiles with a passive device that simultaneously silences the outgoing exhaust while collecting heat. As the muffler is intrinsically involved in treating the loud exhaust produced by an automotive engine, it serves as an ideal location for recapturing the heat generated by said engines and overall improving the efficiency of the system that it is tied into. Previous work has found that the heat transfer to the walls of a concentric tube silencer has a noticeable effect on the frequency bands of the silencer’s overall transmission loss characteristics.