Fluid dynamic and acoustic processes in a single chamber silencer: Transmission loss and heat recovery

A single chamber concentric tube silencer (muffler) is modeled and studied for its fluid dynamic and acoustic properties. The silencer has also been studied for its ability to reduce noise and transfer heat to a thermoelectric generator surrounding it. Two silencer geometries are considered, one with round and the other with square cross-sections. The heat transfer to the walls of a concentric tube silencer affects the frequency bands of the silencer's overall transmission loss characteristics. The sound reduction study considers both a broadband signal source and a single pure tone source. Voltage generation is predicted with this model for a given cooling condition, which agrees with known engineering data and previous studies using these particular thermoelectric generators. The silencer wall-cooling is coupled to the general flow, heat transfer, and its acoustic performance.