An integrated modeling and simulation approach for flow-generated sound prediction.

摘要

One of the most practically important problems of computational aeroacoustics is accurate and efficient calculation of a flow around solid obstacles of arbitrary shape, possibly moving or deformable. In this dissertation, an integrated approach for modeling and simulation of flow-generated sound prediction is considered. The approach integrates the efficient representation of complex geometries using the Brinkman penalization method, the small computational domain using nonreflecting boundary conditions, automatic and adaptive grid generation using the Adaptive Wavelet Collocation Method (AWCM), and far-field acoustic prediction using Ffowcs Williams and Hawkings (FWH) analogy for flow-generated sound prediction. For compressible flows around solid obstacles of complex geometries, a Brinkman penalization method is developed, based on a physically sound mathematical model. For numerical efficiency and affordability, nonreflecting boundary conditions are developed for nonlinear multidimensional flows, which significantly improve the classical nonreflecting boundary conditions for general flows. The Brinkman penalization method and nonreflecting boundary conditions are integrated together with AWCM and FWH into a flow simulation and acoustic prediction environment for flows in arbitrary complex geometries, using Direct Numerical Simulation and Unsteady Reynolds Averaged Navier-Stokes simulations.