中文摘要：

为了考察空腔产生的水动噪声，对气动声学理论与研究方法进行了分析，确立了大涡模拟一等效声源混合法．利用大涡模拟计算空腔非定常流动的流场结构，基于有限元／无限元法利用变分形式的Lighthill声类比方程进行声场的求解．利用该混合法考察了雷诺数为1．2×10^5的空腔算例频域内噪声的辐射特性，基频值的预测结果与文献基本一致，低频纯音的远场辐射具备指向性，沿上游方向辐射能量较高，高频宽带噪音的传播不具指向性．

英文摘要：

In order to investigate hydrodynamic noise generated by flow over an open cavity, aeroacoustic theories and the computational aeroacoustic （CAA） methodologies were analyzed and a hybrid large eddy simulation （LES） equivalent acoustic source method was formulated. In the coupling procedure, the unsteady cavity flow field was computed using LES, while radiant sound was calculated using Lighthill＇s acoustic analogy based on the finite/infinite element method. Then, the frequency domain of the radiant noise of an open-cavity flow at a Reynolds number of I. 2 × 10^5 was investigated. Predictions of the fundamental frequency made with this method agreed well with fig- ures in the literature. The noise propagates predominantly upstream of the cavity in the low-frequency domain and with a flatter directivity in the high-frequency domain.