DTMB 4119螺旋桨噪声特性的数值模拟

将DTMB 4119型螺旋桨作为研究对象，在敞水和伴流条件下分别计算水动力学特性和非空化噪声声压级. 在多个进速系数下对单桨模型的敞水性能展开验证，与文献实验值比对验证准确性后，引入FW-H声类比方程求解监测点声压及频谱. 结果表明，现有模型可以在多个进速系数下取得较吻合的数值结果；单极子和偶极子噪声频谱在低频段出现显著高于宽带的线谱噪声，频率与桨叶BPF及谐波对应. 在轴向平面内，单极子噪声声压级呈现出8字形的分布特征，偶极子噪声声压级呈现出∞型的指向性分布. 伴流场不会改变单、偶极子总声压级的指向性，但会使得各方向线谱噪声声压级趋于均匀. 在径向平面内，单、偶极子的噪声声压级指向性不明显.

Numerical simulation of acoustic characteristics on DTMB 4119 propeller

The hydrodynamic characteristics and non-cavitation noise sound pressure level were calculated considering open-water and wake flow conditions by taking DTMB 4119 propeller as research object. The open-water performance of single propeller was verified under various advance ratios by comparing with the literature experiment results. Then the FW-H analogy equation was introduced to calculate the acoustic pressure of the probes and their spectra. Results showed that the numerical results accorded well with the previous experiments in hydrodynamic performance for different advance ratios. The monopole and dipole noise spectra present marked tonal noise with higher sound pressure level than broadband spectra. Their frequencies corresponded to the blade BPF and its harmonics. The monopole noise presents apparent figure-8 source directivity distributions, and that of the dipole noise presents figure-∞ distributions in the axial plane. The wake field will not change the directivity of total sound pressure level of monopole and dipole, but it will make the sound pressure level of tonal noise in each direction tend to be uniform. The noise directivities of monopole and dipole are no longer obvious in the radial plane.