拖车转向架气动噪声数值研究

拖车转向架作为高速列车最主要的气动噪声声源,由于其结构复杂、细小部件多、周围涡流分布紊乱等,对拖车转向架的气动力和气动噪声认识甚少。采用定常RNG k-ε湍流模型与宽频带噪声源模型对拖车转向架的气动阻力、气动升力和气动噪声声源进行初步探讨,并结合非定常大涡模拟与Lighthill声学比拟理论对其进行远场气动噪声分析。计算结果表明:较大漩涡存在于空气弹簧与抗蛇形减振器之间、迎风侧轴箱与构架侧梁外侧的邻近区域;气动阻力、气动升力与运行速度的平方成正比关系,占总气动阻力最大的部件依次为构架(24.02%)、轮对(19.30%)、枕梁(18.08%)、制动闸片、抗侧滚扭杆、制动盘、构架支架和空气弹簧,枕梁的气动升力最大且占总气动升力的157.88%左右;轮对、构架、制动闸片、制动盘、枕梁、垂向减振器、抗侧滚扭杆等凸起部位的迎风侧表面为拖车转向架的气动噪声源,且构架对拖车转向架总噪声的贡献量最多,其次为轮对,然后为盘形制动装置和枕梁,抗侧滚扭杆、垂向减振器、空气弹簧和横向减振器对总噪声的贡献量较少。拖车转向架远场气动噪声是宽频噪声,具有噪声指向性、衰减性和幅值特性等,主要能量集中在28~56 k Hz频率范围内,中心频率为50 Hz、100 Hz、160 Hz在低频部分能量较大且分布规律不随运行速度的改变而变化。

Numerical Research on Aerodynamic Noise of Trailer Bogie

As one of the main aerodynamic noise source of high-speed train, the trailer bogie is a complex structure containing many components and the distribution of the flow field around a vortex disorders, for trailer bogie aerodynamic forces and noise are poorly understood. According to the models of steady-state RNGk-ε turbulence and the broadband noise source, carry on a preliminary study for the trailer bogie aerodynamic drag, aerodynamic lift and aerodynamic noise source, and combine with the large eddy simulation of transient state and the theory of acoustic analogy, analyze the far-field aerodynamic noise. The results show that: the larger vortex exists between the air spring and anti-yaw vibration absorber, nearby the adjacent area of windward’ axle box and the frame’ side; The aerodynamic drag, aerodynamic lift are proportional to the square of running speed; The largest component of total resistance are frame(24.02%), wheel set(19.30%), corbel(18.08%), brake pad, antiroll torsion bar, brake disc, frame bracket and air spring, what’s more corbel lift is the maximum which is about 157.88% of the total lift; Wheel set, aframe, brake pad, brake disc, corbel, vertical shock absorber, antiroll torsion bar and other parts which is windward side surface are the noise source of trailer bogie. In addition that frame has the largest contribution for the bogie’s total noise, second is the wheel set, then are the brake discs and corbel. Antiroll torsion bar, vertical shock absorber, air spring and horizontal shock absorber have less contribution to the total noise. Far-field noise of trailer bogie is broadband noise that has noise directivity, attenuation characteristic and amplitude characteristic. The main energy is concentrated in the range of 28-56 kHz. Lowfrequency energy of aerodynamic noise of trailer bogie main exist 50 Hz, 100 Hz and 160 Hz, and it’s distribution’s regular does not change with the speed of change.