Numerical Simulation of Aerodynamic Sound by the Finite Difference Lattice Boltzmann Method

J. Ocean Eng. Technol. 2004;18(2):10-17.

차분격자볼츠만법에 의한 유동소음의 수치계산

강호근,김은라

경상대학교 기계항공공학부ㆍ해양산업연구소,전북대학교 토목공학과

Keywords: Aerodnamic Sound, Mach Number, Aeolian Tone, Finite Difference Lattice Boltzmann Method, BGK Model

핵심용어: 유동소음, 마하수, 유동음, 차분격자볼츠만법, BGK 모델

Abstract

In this research, a numerical simulation for the acoustic sounds around a two-dimensional circular cylinder in a uniform flaw was developed, using the finite difference lattice Boltzmann model. We examine the boundary condition, which is determined by the distribution function concerning density, velocity, and internal energy at the boundary node. Pressure variation, due to the emission of the acoustic waves, is very small, but we can detect this periodic variation in the region far from the cylinder. Daple-like emission of acoustic waves is seen, and these waves travel with the speed of sound, and are synchronized with the frequency of the lift on the cylinder, due to the Karman vortex street. It is also apparent that the size of the sound pressure is proportional to the central distance to the circular cylinder. The lattice BGK model for compressible fluids is shown to be a powerful tool for the simulation of gas flaws.