圆柱-翼型干涉流场及噪声数值模拟研究

Numerical Simulation of the Flow and Acoustic Field of A Cylinder Wake-airfoil Interaction

本文采用Ffowcs Williams and Hawkings(FW-H)声类比法对圆柱-翼型干涉流场在来流翼弦雷诺数Rec=4.8×105条件下的噪声指向性分布规律进行了研究。研究了不同精度的湍流求解方法RANS和DDES对流场中速度分布以及非定常速度脉动的预测准确性,进一步对流场中不同位置的声压级进行预测。通过与实验数据对比,验证并且评估FLUENT中FW-H气动噪声模型的精度,最后对圆柱翼型间的不同距离和来流速度对各个噪声监测点的总声压级影响进行了研究,讨论其对噪声的影响规律及噪声的指向性分布规律。本文研究结果有助于验证气动模型准确性,对于下一步采用该模型预测其它复杂结构产生的气动噪声问题具有指导意义。

In this paper,the Ffowcs williams and Hawkings(FW-H)acoustic analogy is used to investigate the noise directivity of the cylinder airfoil test case with the inflow velocity U∞=72m/s and airfoil-chord based Reynolds number Rec=4.8×105.The mean velocity distribution and velocity fluctuations in the turbulent flow field by using different approaches,including URANS and DDES,are investigated and the sound pressure levels at different locations in the flow field is predicted.Validation and evaluation of the accuracy of the FW-H aerodynamic noise model in FLUENT is performed by comparing the results with experimental data.Finally,the effects of distances between the cylinder and airfoil,the effects of inflow velocity on the overall sound pressure level at every noise monitoring point are studied and the influence on the noise and the directivity of the noise are discussed.The results in this paper are useful to validate the accuracy of the numerical model to predict aeroacoustic field,and the model will be used in the prediction of aerodynamic noise generated by other more complicated applications in the next step.