円筒境界層における低周波音発生機構(境界層・せん断流・遷移(2),一般講演)

概要

論文の詳細を見る
Spatial direct numerical simulations are used to study the development of turbulent structures and the resultant sound emission mechanism in a compressible boundary layer, for a high-speed train model conducted in a moving model facility, where the free stream velocity is 500Km/h (corresponding Mach number is 0.41). In the simulation, finite difference upwind-biased compact schemes are employed. Disturbances of compressible isotropic turbulence are superimposed on the laminar profile at the inlet boundary layer in the computational box. The Reynolds number at the inlet based on the displacement thickness is 1640, which meets the measurement of the boundary layer undergoing transition. Simulation results present the complex development of the hairpin vortices leading to turbulent boundary layer structures associated with sound generation. The numerical aerodynamic noise frequency range and the attenuation of sound show a good agreement with the experimental results.
日本流体力学会の論文
2007-08-06