A coupling method for hybrid CFD-CAA simulations using a dual mesh approach

摘要

Noise prediction, reduction and design inside cars passenger compartments gains increasing interest. In this context numerical methods get more important in order to predict the noise of HVAC systems. In this work a hybrid method is presented for the simulation of aeroacoustic noise, based on Lighthills analogy. Therefore in the first step a transient fluid dynamics simulation using the LES turbulence model and finite volume discretization approach is carried out. The aeroacoustic sources appearing are calculated on an especially created finite element grid, which is dual to the CFD grid. This approach avoids interpolation during the acoustic source calculation. In the last step the sources are interpolated onto an acoustic simulation grid and the noise propagation is calculated by solving the wave equation in a finite element scheme. The model simulated was a simplified HVAC outlet consisting just of a plate inside a channel. This way a significant Parker type mode appears, which can be compared to experiments as well as analytics and shows good agreement.