Block-structured adaptive mesh refinement for computational aeroacoustics

High-order spatial discretization schemes based on block-structured adaptive mesh refinement (AMR) method are developed to solve computational aeroacoustics (CAA) problems, with the aim of improving efficiency and reducing costs. In this presentation we present several aspects of AMR application. Firstly, the AMR algorithm will be introduced. Basic work flow charts and pseudo codes are provided. The cost of parallel AMR operations is profiled to show that its burden is not significant. In the second part a number of numerical issues including implementation of high-order spatial schemes (dispersion-relation-preserving scheme and optimized prefactored compact scheme), fine-coarse interfaces under the AMR environment, stability analysis and filter/damping techniques are addressed. To demonstrate the feasibility and efficiency of the approach, the code is applied to some benchmark CAA problems. In particular the problem of spinning modal wave radiation from an unflanged duct is considered. The computed far-field sound directivity is found to agree well with analytical solutions, and the computing time is about one third of that on a uniform mesh. Finally a realistic engine intake problem is studied to show the working of parallel AMR code