单叶片桨噪声相移叠加法预报多叶片船舶螺旋桨非空化低频噪声

单个桨叶噪声预报螺旋桨非空化噪声可显著降低计算耗时,本文联合URANS和声类比方程对该方法进行验证,并对螺旋桨噪声的时域特征进行分析。首先计算均匀流中E779A螺旋桨的声辐射,揭示了桨叶上声压分布及测点声压信号的典型周期特征,采用单个叶片噪声相移叠加(简称"单叶片方法")预报螺旋桨噪声的结果,与对螺旋桨所有叶片积分的计算结果吻合良好,验证了均匀流中单叶片方法的可行性。将该方法应用于潜艇伴流场中无侧斜和大侧斜螺旋桨噪声辐射计算,预报结果与所有叶片积分的结果吻合较好,验证了非均匀流场中单叶片方法的可行性,说明单叶片相移叠加法预报螺旋桨普遍进流条件下的辐射噪声是可行的。研究结论也可为对转桨、泵喷等噪声预报提供参考。 

Prediction of propeller non-cavitation noise by superimposing shifted sound signal from an isolated blade

The time-cost of the propeller non-cavitation noise prediction can be greatly reduced by the isolated blade method, which is validated via hybrid URANS and acoustic analogy, followed by the acoustic characteristics of propeller in time domain are analyzed. Firstly the sound of the E779A propeller operating in uniform inflow is predicted and validated. Typical periodic characteristic of the sound pressure distribution on each blade and the sound signal of the receiver is observed, and the result by the superimposing shifted sound signal from an isolated blade (isolated blade method) agrees well with that of by total blades, which validates the credibility of the isolated blade method in uniform inflow. Finally, the sound of a propeller running in the wake of submarine is predicted by the isolated blade method, and the result also agrees well with that of by the integration on total blades, which indicates that the isolated blade method is also applicable for the non-cavitation noise prediction of the propeller running in non-unifbrm inflow. The noise prediction of the counter rotating propeller, the pumpjet can also benefit from this.