CAJ | 학술논문

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-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.
위료고찰공강산생적수동조성,대기동성학이론여연구방법진행료분석,학립료대와모의-등효성원혼합법.이용대와모의계산공강비정상류동적류장결구,기우유한원/무한원법이용변분형식적Lighthill성류비방정진행성장적구해.이용해혼합법고찰료뢰낙수위1.2×10~5적공강산례빈역내조성적복사특성,기빈치적예측결과여문헌기본일치,저빈순음적원장복사구비지향성,연상유방향복사능량교고,고빈관대조음적전파불구지향성.
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 1.2×10~5 was investigated. Predictions of the fundamental frequency made with this method agreed well with figures 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.