Aeroacoustic Simulations for Complex Geometries Based on Hybrid Meshes

Abstract

This paper advances the idea of a heterogeneous domain decomposition for Computational Aeroacoustics (CAA). Direct simulations of aeroacoustic problems are accelerated by sub-dividing the computational domain into smaller domains. In each of these subdomains the equations, the discretization, the mesh and the time step may be different and are adapted to the local behavior of the solution. High order methods such as ADER-Finite Volume and ADER-Discontinuous Galerkin methods are used to reduce the total number of elements and to ensure good wave propagation properties. Here, we add a high order Finite Difference method to the acoustic solvers and integrate it into the coupling framework. The new scheme shows good performance properties for the convective transport of a Gaussian pulse in density. In the examples section, convergence rates for the coupling procedure in 3D show that high order of accuracy is maintained globally also for partitioned domains. A numerical example that involves multiple domains underlines the flexibility of the approach. Another example shows that the proposed domain decomposition also holds for the coupling of the Navier-Stokes equations with the Linearized Euler Equations.