Silencer Design Methodology for Motorsport Prototypes 2019-36-0295
Exhaust silencer design in motorsport is a matter of establishing the best compromise between rules compliance, mass savings and engine restriction. A design methodology that acknowledges these difficulties is likely to be desirable to ensure that the best solution is always provided for the competing team. The present work takes into account a comprehensive analysis of mass versus silencer restriction matter, based on simulated lap times to find the optimal compromises. A thorough discussion concerning the different techniques concerning passive noise control is held, establishing a widely comprehensive concept study phase. Further optimisation of the best concept is conducted via Design of Experiments. A final finite element analysis is conducted in order to assess the quality of the proposed solution across a larger range of frequencies and confirm the design formulated so far as effective. Checking the transmission loss curve against the known sound power curve of the engine makes possible to know beforehand whether the design will comply with the applicable standards or not. Application of such methodology in a motorsports case has provided a prototype silencer that complies to noise standards. Noise testing conducted with Class A measurement devices provided readings of 107 dB(C), 3 units below the limit of 110 dB(C) while keeping engine restriction to a minimum. The final design imposes a peak power loss of only 4.5% (3.5 HP).