Numerical Insight into Sound Sources of a Rod-Airfoil Flow Configuration Using Direct Noise Calculation

Abstract

The sound radiated by an airfoil in the wake of a rod is predicted by means of compressible large-eddy (LES) simulation. The LES strategy is based on high-order spectral-like numerical methods to allow the direct noise calculation of the sound sources. Owing to the complexity of the geometry, an overset grid approach is implemented in order to tackle with turbulent flows around multiple solid bodies. The aerodynamic data as well as the acoustic far-field are thoroughly compared to the experimental data of Jacob et al. [J. Theoret. Comput. Fluid Dyn., 19(3), 2005] in order to demonstrate the accuracy of the present simulation.

Prediction of the sound generated by a rod-airfoil configuration using a compressible unstructured LES solver and a FW-H analogy

“…1. They are compared with the experimental results, with the compressible LES of Berland et al 10 and with the incompressible LES of Eltaweel & Wang. 11 The asymmetric pattern of the experimental curves is most likely caused by the misalignement of the rod with the airfoil.…”

“…Berland et al 3,10 carried out a compressible LES using a high-order scheme on a mesh of 20 million cells and with an overset grid strategy to cope with the limitations imposed by a block-structured mesh. A direct noise computation is made to propagate the sound waves and aims at studying the coupling between the hydrodynamic and the acoustic part of the flow.…”

Aerodynamic Noise Prediction for a Rod-Airfoil Configuration using Large Eddy Simulations

“…Berland et al 4 performed direct noise computations for the rod wake-airfoil interaction problem using high-order, compressible LES on overset structured grids. They also investigated the effect on noise of varying the spacing between the rod and the airfoil.…”

Experimental study of vortex–structure interaction noise radiated from rod–airfoil configurations

“…These investigations presented results which were in agreement with the experiments, but the applied numerical methods decouple the aerodynamic and acoustic fields, which makes it difficult to determine the details of the flow physics that are responsible for the noise generation. Recently, Berland et al (2010Berland et al ( , 2011 performed a direct noise calculation (DNC), based on compressible LES, to predict the sound radiation from the rod-airfoil configuration. The DNC method does not require any modelling of the sound sources and computes aerodynamic and acoustic fluctuations within a single run.…”