An Overset Finite-Element Large-Eddy Simulation Method With Applications to Turbomachinery and Aeroacoustics

Abstract

A numerical method for the prediction of an unsteady fluid flow in a complex geometry that involves moving boundary interfaces is presented in this paper. The method is also applicable to the prediction of the far-field sound that results from an unsteady fluid flow. The flow field is computed by large-eddy simulation (LES), while surface-pressure fluctuations obtained by the LES are used to predict the far-field sound. To deal with a moving boundary interface in the flow field, a form of the finite element method in which overset grids are applied from multiple dynamic frames of reference has been developed. The method is implemented as a parallel program by applying a domain-decomposition programming model. The validity of the proposed method is shown through two numerical examples: prediction of the internal flows of a hydraulic pump stage and prediction of the far-field sound that results from unsteady flow around an insulator mounted on a high-speed train.