MIE.56 – Design and Development of a Formula SAE Muffler with a Focus on Sound Attenuation

• Chinmay Choudhary
• Parth Dhanani
• Michael Hernandez
• Steve Pappas

In an effort to demonstrate engineering principles in product development, the UIC FSAE team sponsored a project to design an optimized muffler in accordance with Formula SAE (FSAE) rules and standards. Mufflers are a key component of the exhaust system, in which the priority is to reduce noise emission which is created by the combustions within the engine. Standard mufflers lack noise attenuation properties specified for the application of the FSAE vehicle due to the unique placement and size constraints. In addition to acoustic properties, non-acoustic properties must also be taken into account for muffler design such as weight, serviceability, and longevity. The UIC FSAE team needed a solution that included a way to repackage the muffler with sound absorbing material in case of a failure at the track. Mufflers can have several different unique design elements, which include but are not limited to baffles, sound absorption material, perforation tubing, and other geometric shapes meant to disturb the flow of exhaust gasses. The designs are tested using ANSYS Harmonic Acoustic simulations to measure the transmission loss and are tested for backpressure using ANSYS Fluid Flow (Fluent). The goal of this project was to analyze the most effective muffler design for a priority in sound attenuation of a maximum of 103 Decibels at idle and a maximum of 110 Decibels at all other engine speeds, weight loss of approximately 30%, and minimal backpressure. The final muffler design was able to achieve a maximum transmission loss of around 35 Decibels, reduced weight by 23%, and reach 38.2 kPa of backpressure at maximum rpm’s.