Production cost development for commercial exhaust systems

Muffling devices are essential parts of any vehicle/machine that uses internal combustion engines. From automotive manufacturers point of view, they contribute massive sheet metal processing and production time, especially mufflers that are produced at high rates for commercial vehicles. This paper is concerned with applying manufacturing procedures to reduce the production cost of any commercial automotive mufflers through theoretical studies and experimental measurements verification. Mufflers design parameters such as transmission loss, flow generated noise and pressure drop were selected for performance judgment, parameters were simulated and experimentally measured. The transfer matrix method was used to calculate the propagation of sound waves along the muffler. A commercial automotive muffler with a hybrid combination of dissipation and reflection was selected for application and a new design was proposed for this muffler with a reduced manufacturing cost. The manufacturing processes were reduced by 77.7% and consequently the cost relative to the original muffler. Keywords: Commercial vehicle, Vehicle economics, Perforated muffler, Dissipative muffler, Exhaust system manufacturin