高速列车转向架舱对转向架区域流场与气动噪声影响

根据涡声理论和声比拟方法,数值模拟了高速列车转向架简化模型的流场与气动噪声特性,分析了转向架舱对转向架流动与气动噪声性能的影响.结果表明:在单独转向架与转向架位于转向架舱内2种工况下,几何体近壁流场内形成的体偶极子声源为近场四极子噪声的主要声源,转向架表面压力脉动产生的面偶极子声源为声辐射主要声源;与单独转向架相比,转向架舱改变了转向架流动特性与声辐射指向性,削弱了转向架所产生气动噪声的强度,但转向架舱后壁会产生较大气动噪声.

Effect of Bogie Cavity on Flow and Flow induced Noise Behavior Around High speed Train Bogie Region

The behaviors of flow and aerodynamic noise produced around a high speed train bogie are studied numerically at a scaled model based on the theory of vortex sound and the acoustic analogy method in this paper. The effect of bogie cavity on the flow and flow induced noise performance is investigated. Results show that for isolated bogie and bogie inside cavity cases, the volume dipole is the predominate source of near field quadrpole noise generated in the wake region close to the geometries. Moreover, as the main aerodynamic noise source for far field noise radiation, the surface dipole noise is produced from the pressure fluctuation on the wall surfaces around the bogie areas. Compared with the isolated bogie configuration, the bogie cavity changes the flow around the bogie for the bogie inside cavity case and consequently the directivity of the noise generated from the bogie wall surfaces is altered and the radiated aerodynamic noise level is reduced. However, the strong noise is generated on the rear wall of the bogie cavity.