湍流边界层激励下平板辐射噪声数值计算方法

摘要

As the turbulent boundary layer (TBL) is one of the most important sources of vibration and noise in underwater vehicles, there is an important significance in studying the numerical method for the calculation of flow-induced noise. In this paper, the methods of Principal Component Analysis (PCA) and Vibro-Acoustic Transfer Vectors (VATV) based on LMS Virtual Lab software are used to calculate the sound characteristics of a plate structure excited by TBL. The Corcos model of the wave number-frequency spectrum of the wall pressure field beneath the TBL is used to describe random excitation. By comparing the calculating time and sound pressure auto power spectra curves of the two methods, the following conclusions are obtained: both the VATV method and PCA method can be used effectively for the calculation of the flow-induced noise of structures excited by the TBL, and the results of the two methods match; the VATV method can quickly forecast the structure of flow-induced noise and takes up fewer computing resources than the PCA method; the PCA method can also obtain the structure vibration response in comparison with the VATV method. The current work can serve as a reference for the rapid prediction of the flow-induced noise of underwater structures.%[目的]湍流边界层(TBL)激励下的结构辐射噪声(也称"流激噪声")是水下航行体的重要噪声源,因此,对流激噪声数值计算方法的研究具有重要意义.[方法]基于LMS Virtual Lab数值计算软件,以Corcos湍流脉动压力频率波数模型作为输入,采用主成分分析(PCA)法和振动—声传递向量(VATV)法计算湍流边界层激励下平板结构的流激噪声,并对两种方法的正确性进行验证,比较分析两种方法的计算时间及得到的声压自功率谱密度(ASD)曲线.[结果]结果表明,这两种方法均可有效计算湍流边界层激励下的结构流激噪声,且计算结果基本一致;和PCA法相比,VATV法所占用的计算资源更少,能快速预报结构的流激噪声;相较于VATV法,PCA法还可以得到结构振动响应结果.[结论]该研究结果对水下结构流激噪声快速预报具有一定的参考价值.