加速旋转螺旋桨噪声测试水洞试验研究

Study on Cavitation Tunnel Experiment of Accelerating Rotating Propeller Noise

为了获取船舶螺旋桨在加速旋转状态下辐射噪声与螺旋桨转速之间的关系,在国际标准的大型循环水洞开展了加速旋转螺旋桨噪声测试试验研究。首先以水洞试验相似准则为约束,分析了在进行模型桨模拟实桨加速过程的噪声测试时需要满足的试验条件,提出了相应的试验工况设计方法。并且,提出了一种从螺旋桨动力仪输出的脉冲信号中获取螺旋桨转速参考值的方法,避免了在加速时脉冲重复周期不断变化给测量精度带来的影响。最后基于Radon变换分析了实测的螺旋桨噪声数据,分析结果表明,试验数据蕴含了螺旋桨转速变化的信息,有助于进一步进行加速旋转螺旋桨辐射噪声信号特性及分析方法的研究。

In order to obtain the relation between radiated noise and propeller noise while ship propeller is in accelerating propelling, a data acquisition test with an accelerating propeller was performed in the international large scale cycling cavitation tunnel. For t he simulation of cavitation noise during the acceleration process of actual prop eller, the experimental condition and operating condition design procedure were proposed under the constraint of scaling law. Moreover, the method of acquiring nominal value of propeller rotation speed from the output pulse signal was given , it avoided the influence to the measuring accuracy caused by continuously changing of pulse repetition period while accelerating. Finally based on Radon alte rnation, the measurement of propeller noise was analyzed. The data analysis resu lts show that the variation of propeller rotation speed is implied in the cavita tion noise of accelerating propeller, which is benefit for the further study on hydro-acoustic signal feature of accelerating propeller noise and the feature e xtraction algorithm.