Computational Aeroacoustics with Higher Order Methods
The Lighthill acoustic analogy in combination with two different higher-order CFD solvers is used to investigate the sound generation of two test cases. The flow around a cylinder at Re = 150 is analysed with a Discontinous Galerkin method and a counter-r
- PDF / 656,602 Bytes
- 15 Pages / 439.36 x 666.15 pts Page_size
- 31 Downloads / 190 Views
Abstract The Lighthill acoustic analogy in combination with two different higherorder CFD solvers is used to investigate the sound generation of two test cases. The flow around a cylinder at Re D 150 is analysed with a Discontinous Galerkin method and a counter-rotating open rotor (CROR) with a WENO scheme. The simulation of the cylinder is able to predict both aerodynamic and acoustic behaviour correctly, the vortex street behind the cylinder is responsible for the noise radiation similar to of an acoustic dipole. The analysis of the CROR focuses on the effect of using a higher-order method with a detailed comparison with a standard second order method. While global aerodynamic forces show only small differences, the better transport of vortices, especially of the blade tip vortex, is a benefit for the prediction of interaction noise of the two rotors. This paper includes different investigations on the new HLRS Cray Hermit cluster. The DG code was optimized for single-core usage while still maintaining its good parallel performance. The effect of node-pinning is studied with the CROR configuration which improved the computational time slightly.
1 Introduction For recent research in aerospace engineering, computational fluid dynamics (CFD) in combination with computational aeroacoustics (CAA) has developed to a useful tool to examine flow fields and acoustic emission caused by flow phenomena, in addition to experiments. With the continuous growth of supercomputing power it is now not only possible to simulate setups with several million cells in acceptable
E.R. Busch () M.S. Wurst M. Keßler E. Kr¨amer Institut f¨ur Aerodynamik und Gasdynamik, Universit¨at Stuttgart, Pfaffenwaldring 21, D-70569, Stuttgart, Germany e-mail: [email protected] W.E. Nagel et al. (eds.), High Performance Computing in Science and Engineering ’12, DOI 10.1007/978-3-642-33374-3 19, © Springer-Verlag Berlin Heidelberg 2013
239
240
E.R. Busch et al.
time, also the use of higher order methods is a possibility. At the Institute of Aerodynamics and Gas Dynamics (IAG) of the University of Stuttgart the development of higher order codes used for CFD simulation of helicopters has been one of the main research fields. Current CFD simulations often include acoustic evaluation since noise emission of aircrafts plays a more and more important role due to its high annoyance to the community. Aeroacoustics are a part of the current research at IAG. In this paper two test cases were simulated with different numerical methods and then examined acoustically. A cylinder at a Reynolds number Re D 150 has been simulated with the higher order Discontinuous Garlerkin (DG) Code SUNWinT developed by IAG. The SUNWinT Code is still being enhanced and will be used for CFD simulation of helicopters and other applications. Subsequently an acoustic analysis has been carried out with the IAG-tool ACCO, which uses the Ffowcs Williams-Hawkings (FW-H) equation for acoustic modelling. As a practical application, a counter-rotating open rotor at take-off
Data Loading...
