Aeroacoustic formulations for coupling of confined flows with the flow-guiding structure

The absence of combustion noise in electric vehicles results in a dominance of other sound sources, such as flow-induced sound in flow guiding components. The use of Computational Aeroacoustics (CAA) during the design phase is a promising way to fulfill packaging requirements and the ambitious demand for passenger comfort. By coupling the computational fluid domain with the surrounding structural domain through appropriate interface conditions, the sound generation and propagation within the fluid can be computed, and the vibroacoustic sound emission of the flow-guiding structure can be predicted.
For doing so, we apply a hybrid approach for the computation of the flow-induced sound, where we couple the fluid domain with the flow confining structure. Thereby, different aeroacoustic formulations, such as Lighthill’s wave equation and the Perturbed Convective Wave Equation (PCWE), are compared regarding the suitability for this purpose. First, an incompressible Large Eddy Simulation is performed, and subsequently, the coupled acoustic propagation simulation is conducted. The comparison considers typical flow configurations of turbulent low Mach number airflows (Ma