水面舰船声隐身性能影响作战效能的因素初探

  目的  为研究不同湍流模型在螺旋桨流噪声预报中的适用性，以DTMB 4119螺旋桨为研究对象，对非均匀进流条件下的频域噪声进行数值模拟。  方法  首先，采用RANS方法计算螺旋桨在不同进速下的水动力系数和桨叶表面压力分布，并将仿真值与试验值进行比较，验证流场模拟的准确性；然后，分别将RANS，DES和LES这3种方法得到的脉动压力作为声源，结合声学边界元预报辐射噪声。  结果  计算结果表明，线谱噪声是螺旋桨总噪声的主要贡献者；当预报一阶叶频上的噪声时，3种方法所得结果较为接近，可以采用RANS方法进行快速预报；当预报高阶叶频上的噪声时，采用LES方法预报的结果更加准确。  结论  在噪声预报时可以根据需求选择合适的湍流模拟方法。

Influencing factors on the combat effectiveness of acoustic stealth performance for surface ship

  Objectives  In order to study the applicability of different turbulence models in propeller flow noise prediction, taking the DTMB 4119 propeller as the research object, the numerical simulation method is used to calculate the frequency domain noise under the non-uniform flow field.  Methods  First, the hydrodynamic coefficient and surface pressure distribution coefficient are obtained via the RANS method and the accuracy of the flow field simulation is verified by comparing it with the experimental data. Next, the pulsating pressures obtained by RANS, DES and LES are considered as the sound source respectively, and combined with the acoustic boundary element method to predict the radiation noise.  Results  The results show that spectral noise is the main contributor to total noise; when noise on 1 BPF is predicted, the results obtained by the three methods are very similar, so we can use RANS to predict noise quickly; when noise on the high order of BPF needs to be predicted, the calculation results of LES are better.  Conclusions  In noise prediction, the appropriate turbulence simulation method can be selected according to the demand.