The Study On Vorticity And Hydrodynamic Noise Features Of Finite Cylinder Mount On Wall

This paper presents a simple model, the finite circular cylinder mount on wall as theresearch object. Large eddy simulation is used to simulation the vorticity features of thefinite cylinder. On the basis of the acoustic analogy theory, FW-H equation is utilized toinvestigate hydrodynamic noise characteristics and radiation characteristics.This paper first studies the steady viscous flow field of the finite cylinder, usingRANS equations combined with RNG k-ε turbulent model. The numerical results showgood agreement with the experiment data which indicates that the steady numericalmethods used in this paper is available. Then, LES method is used to simulate theunsteady viscous flow field of a2D rigid cylinder. The Karman Vortex Street, as well asStrouhal numbers fit the published data well also shows the reliable and accuracy of LESmethod.On the basis of primary work, RANS equations combined with RNG k-ε turbulentmodel is used to simulate the wake structure of finite cylinder at various aspect ratios.LES method is utilized to investigate the vorticity features in the wake. The sound field ofthe finite cylinder in different velocity is also obtained in this paper by FW-H equation. Itcan be concluded that large eddy simulation has a good performance in the simulation of3D viscous flow. It can capture the dominant vortex in the wake of finite cylinder. Thefinite cylinder with different aspect ratio has a certain difference in flow structure. Thehydrodynamic noise distribution is different in typical plane of the sound field generatedby finite cylinder. Sound field decays as the spherical surface of point source in far field.Velocity is one of the most significant factors effecting on hydrodynamic noise of finitecylinder.