Aeroacoustic Scattering Using a Particle Accelerated Computational Fluid Dynamics/Boundary Element Technique

Abstract

A particle accelerated computational fluid dynamics/boundary element method technique to predict the sound pressure field produced by low Mach number flow past a rigid body is presented. An incompressible computational fluid dynamics solver is used to calculate the transient hydrodynamic flowfield. A near-field formulation based on Lighthill’s analogy is coupled with a particle condensation technique to predict the incident acoustic field and its normal derivative on the body. The near-field formulation involves singular surface and volume integrals, which are regularized via singularity subtraction. A particle condensation technique is applied to accelerate the incident field computations and reduce the amount of data that must be stored during the computational fluid dynamics analysis. The incident field is then combined with a boundary element method model of the body, and the scattered sound pressure field is obtained by solving the Burton–Miller boundary integral equations. The accuracy and computational cost of the particle accelerated computational fluid dynamics/boundary element method approach is demonstrated by calculating the incident acoustic field on a cylinder in crossflow under laminar and turbulent flow conditions as well as predicting the scattered and far-field sound pressures.