Numerical analysis of effect of splitter plate on aeroacoustics of square cylinder at various Reynolds numbers

Abstract

Noise reduction is a primary area of study in the automotive sector and reduction of aerodynamically generated noise due to flow past bluff bodies is highly desired. Bluff bodies are found in various daily applications like poles, wires, components of vehicles, etc. where they are faced with oncoming flows. The aeroacoustic noise generated due to flow past such bodies is a impact of the vortex shedding phenomenon occurring in the wake of the flows and hence control of the vortex shedding phenomenon is of high importance. In the present study, flow past a square cylinder has been modelled at different Reynolds numbers and the noise generated has been recorded. Modification of the geometry by addition of a splitter plate has been performed and its effect on the flow properties and noise generation has been observed. Flow simulations have been performed using commercial CFD software, ANSYS Fluent. Unsteady two- dimensional analyses have been performed by solving governing equations for incompressible isothermal viscous flow. Large Eddy Simulation (LES) with Smagorinsky-Lilly subgrid model has been employed for turbulence modelling and acoustic modelling has been performed using Ffowcs-Williams and Hawkings model. Flow properties such as coefficients of lift and drag and aeroacoustic parameters such as Overall Sound Pressure Level (OASPL) and Sound Pressure Level (SPL) have been studied. The results are found to be in good agreement with available experimental data.