Case study: Interior noise optimization of a commercial passenger vehicle using Statistical Energy Analysis and Response Surface Methodology

This paper investigates the effect of sound insulation on the acoustic behavior of bus interior cavities in three areas: the driver’s head, the middle passenger’s head, and the rear passenger’s head cavities. For this purpose, which has been done at high frequencies, the VA One® engineering software, which is based on the Statistical Energy Analysis (SEA) method, has been used. After extracting all the equations of the SEA method, all the structural and acoustic subsystems of the bus, as well as the connections between them, have been modeled. Aerodynamic loads at the speed of 80 km/h, airborne engine noise, fan, and exhaust manifold at the back, and airborne tire/road noise as noise sources have been applied separately to the roof, body, and windscreen of the bus. Finally, by using the Response Surface Methodology (RSM), considering the minimum weight and maximum noise reduction, the panels have been optimized to improve the interior sound quality. The results show that using optimized panels reduces overall sound transmission within the bus and specifically improves noise reduction at the driver’s head, middle passenger’s head, and rear passenger’s head cavities by 47.8%, 51.6%, and 69.8%, respectively.