Aeroacoustic Prediction for Effectiveness of Vortex Suppression Methods for Bluff Bodies at Various Reynolds Numbers

Noise of almost every form is considered undesirable and hence its reduction is an important area of study. Aerodynamically generated noise due to vortex shedding in the wake of bluff bodies is a major source of such undesirable noise in applications involving overhead wires, poles, automotive components and aircraft landing gears. Vortex suppression methods are employed in these cases to reduce the noise generated by suppressing the pressure fluctuations arising near the bluff body surface. For the present study, flow past different bluff bodies is simulated using commercial CFD software, ANSYS FLUENT, with and without involving suppression methods. The calculations for flow field are performed by solving the two-dimensional governing equations for unsteady isothermal incompressible viscous flow. Turbulence modelling is performed using Large Eddy Simulation (LES) with Smagorinsky-Lilly subgrid model. Simulations for far-field noise are carried out using Ffowcs-Williams and Hawkings model and different aeroacoustic parameters like overall sound pressure level and sound pressure level are computed for different receiver locations. The effectiveness of different suppression methods is tested at different Reynolds numbers and their performance is compared. The obtained results are found to be in good agreement with available experimental data.