Numerical simulation of flow-induced acoustic oscillations around circular cylinders

Abstract

Questions of numerical simulation of acoustic oscillations generation modes in the liquid flow around the groups of two and three circular cylinders are considered. In mining industry the processes of hydrodynamic impact on gas-saturated porous media produce significant acoustic emission both at the injection stage and at the liquid discharge stage. Simulation of such kind of acoustic processes is one of the actual problems of theoretical and applied fluid mechanics and under certain assumptions could be reduced to the flow around a group of bodies. Two approaches for numerical simulation of the acoustic oscillations generation induced by the flow around circular cylinders based on numerical solution of the Navier-Stokes equations for compressible and incompressible flows closed by differential model of turbulence and complemented by acoustic analogy equations have been developed. For laminar flows, eight different modes that fundamentally differ both in the flow structure and in the frequency spectrum of parameter oscillations have been identified. For turbulent flows, the classification criteria for the three main frequency modes are presented. Acoustic data are obtained using the Direct Noise Computation technology and acoustic analogies as well.