某型振动轮噪声数值模拟及优化分析

空中声源的辐射噪声谱包括宽带连续谱和窄带线谱,线谱能量高于连续谱。与水下声源相比,空中声源的运动速度普遍较高,线谱多普勒频移明显,可用于进行水下对空中声源的运动参数估计。首先通过时频分析提取接收信号的瞬时频率,而后利用非线性最小二乘法将瞬时频率提取值与预测值相拟合,进而估计声源的运动参数(声源的运动速度、静止频率、与接收器最小水平距离及经过最近点时刻)。仿真与实验均能较为准确地估计出声源运动参数,同时在实验中实现了水下对空中运动声源的测距和定位,测距误差小于15.8%。在满足一定信噪比和保证足够多普勒信息的情况下,该参数估计方法具有很好的适用性。

Numerical Simulation and Optimization Analysis of Vibration Wheel noise

Taking a vibration wheel as the research object, the frequency response of the vibration wheel is analyzed based on the dynamic finite element theory, and then the acoustic boundary element technique is used to simulate the radiated noise of the vibration wheel. The accuracy of the simulation results is verified by experiments. Then the effects of vertical vibration and circular vibration on radiation noise are compared, and a conclusion is drawn that the radiation noise of vertical vibration is low. Finally, the acoustic cavity mode of the cab is simulated, which is similar to the excitation frequency of the vibration wheel. By adjusting the excitation frequency, the noise near the driverundefineds ear is reduced. The results obtained in this paper can provide a practical reference for the prediction and improvement of radiated noise of vibration wheel.