对转螺旋桨空化过程的噪声解调谱特性研究

Research on DEMON Characteristics of Counter-Rotating Propeller in the Cavitation Process

依据螺旋桨辐射噪声辐射模型,在实验室环境对空化过程的对转螺旋桨辐射噪声进行解调谱特性研究。分析结果可知,在对转双桨的相互干涉与非均匀性流场的共同作用下,水下对转桨辐射噪声调制谱主要由前后桨叶频及其谐波组合构成,导致对转螺旋桨在运行时辐射噪声具有丰富的目标线谱。对转桨在未空化时,调制作用不明显;对转桨在空化初生状态时,噪声级显著提高,调制深度最深。在完全空化后,幅度调制被空化噪声所掩盖,调制作用下降。

In this paper, the demodulation spectrum characteristics of the counter-rotating propeller radiated noise in the cavitation process are studied in the laboratory environment based on the propeller radiated noise radiation model. The analysis results show that under the combined action of the mutual interference of the counter-rotating propellers and the non-uniform flow field, the radiated noise modulation spectrum of the underwater counter-rotating propeller is mainly composed of the front and rear blade frequencies and their harmonic combinations, resulting in the the radiated noise has a rich target line spectrum. When the counter-rotating propeller is not cavitated, the modulation effect is not obvious;when the counter-rotating propeller is in the initial state of cavitation, the noise level is significantly improved, and the modulation depth is the deepest. After complete cavitation, the amplitude modulation is masked by the cavitation noise, and the modulation effect decreases.