水下对转螺旋桨空化线谱频率预报与数值模拟

摘要

水下高速目标对转螺旋桨常工作在空化状态,其噪声线谱由前后桨相互作用及前后桨与船舶尾流场的相互作用引起.通过Goldstein的声相似方程,将空泡看作螺旋桨的一部分,对空化条件下水下对转螺旋桨的线谱频率进行了理论预报.推导出了远场条件下单极子源性质的声源所产生的声压表达式,得到了其线谱预报频率.利用Schnerr-sauer空化模型及RNG k-ε湍流模型,并采用动网格模型对对转螺旋桨进行空化数值模拟.结果表明:预报的DTMB4381螺旋桨空泡形态与公开发表实验及数值模拟结果吻合度较好.利用该方法得到的对转螺旋桨空化线谱频率与理论预报结果完全吻合.%Underwater high speed target counter-rotation propeller always works at cavitation condition, the cavitation noise line-spectrum is due to the interaction between fore and aft propeller, and the interaction between the fore or aft propeller and wake of the ship. According to the acoustic analogy equation of Goldstein and making vacuole as one part of propeller, the academic prediction of counter-rotation propeller cavitation line-spectrum frequency is presented. The far field sound pressure expression of monopole sound source is deduced, and the line-spectrum prediction frequency is gained. The counter-rotation propeller cavitation is numerically simulated using Schnerr-sauer cavitation model, RNG κ-ε turbulence model and dynamic mesh model. The results shows that the predicted cavity shapes of DTMB4381 propeller agrees well with the experimental observation and numerical simulation result on open literature, and the counter-rotation propeller cavitation line-spectrum frequency is got by this method which agrees with the result of Academic prediction absolutely.