水下对转螺旋桨辐射噪声调制机理与试验研究

Counter-rotation propellers are important thruster for underwater vehicles, the research on the radiated noise characteristics of underwater counter-rotation propeller is an important research topic in the field of detection and recognition of underwater vehicles. The modulation property is one of the important characteristics of counter-rotation propeller radiated noise. The difficulty in describing its modulation characteristic is to establish a modulation model based on its acoustical generation mechanism in the fluid. The existing modulation research is based on the signal hypothesis which lacks the physical foundation. The issues of this project are mainly focused on the following three aspects. Firstly, the modulation model of underwater counter-rotation propeller radiated noise in cavitation and non-cavitation environment are investigated. Secondly,The signal-level data reconstruction method of underwater counter-rotation propeller radiated noise is established by using the mixed numerical algorithm of Boltzmann method and CAA. Thirdly,The radiation noise measurement test of counter-rotation propeller is taken on the cavitation-tunnel and lake to verify the modulation model. The research results of the project include a modulation model of underwater counter-rotation propeller radiated noise, which may provide technical support for the detection and recognition of underwater vehicles.

水下对转螺旋桨是水下航行体的重要推进器，针对水下对转螺旋桨辐射噪声特性的研究是水下航行体探测和识别领域的重要研究方向。调制信号特性是水下对转螺旋桨辐射噪声的重要特征之一，对于其调制特性描述的难点在于根据其在流体中的发声机理建立调制模型，现有研究工作是建立在信号假设近似的基础上，缺乏物理基础。本项目的研究内容包括：建立空化和无空化环境下水下对转螺旋桨辐射噪声的调制模型，采用Boltzmann方法与计算声学(CAA: Computational Aero-acoustics)混合的数值方法建立水下对转螺旋桨辐射噪声的信号级数据重构方法，并在空泡水筒和湖上进行水下对转螺旋桨辐射噪声测量试验，验证调制模型。本项目研究成果给出了水下对转螺旋桨辐射噪声的调制机理，为水下高速航行体目标特性探测和识别提供技术支撑。

水下对转螺旋桨是水下航行体的重要推进器，针对水下对转螺旋桨辐射噪声特性的研究是水下航行体探测和识别领域的重要研究方向之一。水下对转螺旋桨辐射噪声的研究难点在于物理发声机制不明、数值预报精度欠缺和试验测试困难。.本项目针对水下对转螺旋桨辐射噪声特性从理论建模、数值模拟和试验验证的角度展开研究，主要工作总结如下：首先，针对水下对转螺旋桨辐射噪声信号建模问题，基于广义声类比方法建立了水下对转螺旋桨无空化和空化工况下的远场辐射声压模型，进一步建立了辐射噪声的调制模型，理论分析和预报了对转桨辐射噪声线谱的产生机制及指向性特征。其次，针对水下对转螺旋桨辐射噪声信号数据生成的难题，建立了基于计算流体力学（CFD）Boltzmann方法与计算声学（CAA）结合和混合数值模拟方法，开展了对转桨流场数值仿真，在此基础上开展了对转桨辐射噪声信号仿真研究。再次，针对水下对转螺旋桨辐射噪声特性验证问题，构建了模型对转桨辐射噪声测试系统，开展了模型对转螺旋桨无空化和空化辐射噪声试验测试研究，并针对测试环境混响严重的缺点，建立了分频段信号解调算法分析实测数据，验证了水下对转桨辐射噪声理论模型和数值算法的准确性。本项目研究成果为水下对转螺旋桨远场辐射噪声特性分析提供了一种途径，为水下目标的远距离分类识别提供了技术支撑，亦为水下目标的减振降噪提供了理论依据。