孔腔脉动压力及其波数—频率谱的大涡模拟研究

发布时间：2018-08-11 15:06

【摘要】：孔腔流动中包含着流动分离和失稳以及涡旋相互干扰等复杂的流动现象。孔腔涡旋流动引起的流体振荡能够引起脉动压力的显著增加从而产生强烈的噪声,在工程实际中备受关注。湍流脉动压力是流激噪声的重要来源,也是湍流研究中的基础性问题,对其进行数值计算研究是流声耦合领域的重要内容,而湍流脉动压力波数—频率谱的构建更是该领域的技术难点。文章采用大涡模拟方法(LES)对孔腔脉动压力进行了数值模拟,考察了四套网格和四种亚格子应力模型对计算结果的影响,并与试验结果进行比较,验证数值计算方法的可靠性。首先采用大涡模拟方法计算了孔腔的脉动压力,并与中国船舶科学研究中心的空泡水筒试验结果进行对比分析。接着详细地分析孔腔脉动压力,研究亚格子应力模型和网格数量对计算结果的影响。最后,对数值计算得到的脉动压力多元阵列结果进行时间/空间Fourier变换,构建了三维脉动压力波数-频率谱。该文工作对今后流激结构振动噪声的预报和流动控制研究奠定了基础。
[Abstract]:The flow in a cavity contains complex flow phenomena such as separation and instability of flow and vortex interaction. The fluid oscillation caused by the vortex flow in the cavity can cause a significant increase in the pulsating pressure resulting in a strong noise which has attracted much attention in engineering practice. Turbulent fluctuating pressure is an important source of fluid-induced noise and a basic problem in turbulent research. Numerical calculation is an important content in the field of fluid-acoustic coupling. The construction of wave number-frequency spectrum of turbulent fluctuating pressure is a technical difficulty in this field. In this paper, the large eddy simulation method (LES) is used to simulate the fluctuating pressure of the cavity. The effects of four sets of meshes and four sublattice stress models on the calculation results are investigated, and the results are compared with the experimental results to verify the reliability of the numerical method. The pulsating pressure of the cavity is calculated by using the large eddy simulation method, and the results are compared with the experimental results of the cavitation cylinder of the China Shipbuilding Science Research Center. The influence of the sublattice stress model and the number of meshes on the calculation results is studied in detail. Finally, the time-space Fourier transform is applied to the numerical results of the multivariate array of pulsating pressure, and the three-dimensional fluctuating pressure wavenumber frequency spectrum is constructed. The work in this paper lays a foundation for the prediction of vibration and noise of fluid-excited structures and the study of flow control in the future.
【作者单位】：中国船舶科学研究中心水动力重点实验室;
【分类号】：O357.5

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