Vibro-acoustics response of a simplified glass window excited by the turbulent wake of a quarter-spherocylinder body.

Abstract

Inside vehicle cabins, an important part of interior noise is generated from cabin window vibration. The vibration is stimulated by surface pressure fluctuations that are produced by exterior flows and flow-induced noise. To numerically investigate the cabin noise, both exterior flows and noise must be resolved in simulations. This requirement motivates us to utilize advanced computational fluid dynamics (CFD) and computational aeroacoustics (CAA) based on a quarter-spherocylinder body, which is a general model for vehicle mirrors. The blunt body is mounted upstream of a rectangular window of a cuboid cavity. The turbulent flow is simulated using compressible large eddy simulation, compressible detached eddy simulation, and incompressible detached eddy simulation (I-DES). The exterior noise is either predicted by coupling the I-DES with an acoustic wave modeling method, or directly solved using compressible CFD methods. Given surface pressure fluctuations on the window from the CFD and CAA methods, the window vibration and interior noise are simulated with a finite element method. The effects of compressibility, turbulence modeling methods, and grid topology (polyhedral and trimmed elements) are discussed. The computational efficiency of the numerical methods is addressed. The contributions of hydrodynamic and acoustic pressure fluctuations to the interior noise are clarified.