【作者】 王志伟；

【导师】 刘伯胜； 刘文帅；

【作者基本信息】 哈尔滨工程大学 ， 水声工程， 2012， 博士

【摘要】 目前，关于舰船振动噪声的研究多集中在机械设备激励壳体振动声辐射的机理和传递路径研究、推进轴系振动噪声固有结构特征研究、推进器噪声理论预报、机理分析与模型试验等方面，而对舰船总体航行辐射中推进器噪声分离研究、推进器直接辐射噪声分离方法研究较少。因此，开展舰船推进器噪声分离方法研究，对进一步降低舰船辐射噪声水平、评估推进器噪声水平等具有重要意义。针对舰船推进器噪声分离以及推进器直接辐射噪声分离问题开展理论研究、建模仿真分析以及试验研究等。重点研究推进器直接辐射噪声的频谱特征及其随转速的变化规律、推进器通过轴系激励壳体振动噪声的频谱特征，建立总体航行辐射噪声中推进器噪声分离方法、推进器噪声中直接辐射噪声的分离方法，并通过试验分析，验证舰船噪声分离方法的有效性与分离结果的正确性。具体研究内容如下：以偶极子声源的声学特征分析为基础，研究推进器直接辐射噪声的一般声学特征，重点分析推进器直接辐射噪声离散谱以及不同频段连续谱随转速增长的变化规律，为后续研究总体航行辐射噪声推进器噪声分离方法、推进器直接辐射噪声与其激励壳体振动声辐射的分离方法研究提供理论依据。通过理论研究与仿真分析，阐述推进器激励力作用于艇体产生振动噪声的基本物理过程及主要传递路径，研究推进器作用于艇体产生振动噪声的声学模型及信息模型，分析推进器激励壳体振动辐射噪声的频谱特征。为研究推进器直接辐射噪声与其激励壳体振动产生声辐射分离方法提供了基本依据及信息源等支撑。分析机械设备激励壳体振动辐射噪声以及流激壳体振动声辐射的频谱特征，掌握二者与推进器噪声频谱特征的差异，建立不同频段、不同转速推进器直接辐射噪声的数学换算模型，形成总体航行辐射噪声中推进器噪声分离方法、推进器噪声中推进器直接辐射噪声分离方法。分析推进器噪声分离方法对舰船噪声振动综合试验的基本要求，研究试验数据分析方法，通过试验数据处理，验证了推进器直接辐射噪声频谱特征随转速的变化规律以及推进器激励壳体振动声辐射频谱特征的理论分析结果。证实舰船总体航行辐射噪声中推进器噪声分离方法的有效性，推进器直接辐射噪声分离方法的实用性，并通过舰船推进直接辐射噪声分离结果与推进器模型试验结果的对比分析，验证舰船推进器分离方法的正确性。更多还原

【Abstract】 Recently, researches on ship vibration noise are almost focused on aspects such as theprinciples and transfer paths of sound radiations subject to shell vibrations excited bymechanical equipments, inherent structural characteristics of vibration noises of thepropulsion shafting, as well as the theoretical predictions and model tests of propeller noisesand so on. However, studies on noise separation of propellers from the general radiated noisesof ships under service conditions, and separation methods for direct radiated noises ofpropellers from their sound radiations excited by shell vibrations are still relatively rare.Therefore, developing researches on noise separation methods of ship propellers shall have animportant significance for further lowering the radiated noise level of ships, as well as thenoise evaluation of their propellers.In this paper, issues on noise evaluation of propellers and separation methods for directradiated noises of propellers from their sound radiations excited by shell vibrations areresearched, where the spectrum characteristics of direct radiated noises of propellers and theirchange laws with the rotating speed, and the spectrum characteristics of vibration noises ofshells excited by propellers through the propulsion shafting are discussed, a set of noiseseparation method for propellers from the general radiated noises of ships under serviceconditions is established successfully, as well as a method for separating direct radiated noisesof propellers and the sound radiations excited by shell vibrations; further more, by means of aseries of test analysis, the effectiveness and the correctness of corresponding results of theseparation methods for ship noises are verified. Details are as follows:General acoustic characteristics of direct radiated noises of propellers are researchedfirstly based on the analysis of acoustic characteristics of dipole sound sources, where discretespectrums of direct radiated noises of propellers and the change laws of continuous spectrumsof different frequency bands along with the increasing rotating speed are analyzed in depth,providing a theoretical basis for researches on the propeller noise separation method and thegeneral radiated noises of ships, as well as a method for separating direct radiated noises ofpropellers and the sound radiations excited by shell vibrations.By means of theoretical studies and simulation analysis, the basic physical processes andmain transfer paths of propeller’s exciting forces acting on submarine bodies for generatingvibration noises are described, the acoustic model and information model of them are studied,and the spectrum characteristics of vibration radiated noises of shells excited by propellers are analyzed. Works mentioned above together have provided necessary supports such as basicgrounds and information sources for the research of separation methods for direct radiatednoises of propellers and sound radiations excited by shell vibrations.By means of analyzing the spectrum characteristics of vibration radiated noises of shellsexcited by mechanical equipments and the vibration sound radiations of shells excited bycurrent, and making clear their differences between the spectrum characteristic of propellernoises, the mathematical conversion model of propeller’s direct radiated noise of differentfrequency bands and different rotating speeds is established properly; and finally, a set ofpropeller noise separation method from the general radiated noises of ships, and the methodfor separating direct radiated noises of propellers and secondary sound radiations excited byshell vibrations are provided.To apply the propeller noise separation method on ships, basic requirements ofcomprehensive tests of noises and vibrations are analyzed, and corresponding proceedingmethods for test data are studied in depth; by means of test data processing, the change lawsof spectrum characteristic of propellers’ direct radiated noises with rotating speeds areverified, as well as theoretical analysis results of spectrum characteristic of vibration soundradiations of shells by excited the propeller. On the basis of which, the effectiveness of thepropeller noise separation method from general radiated noises of ships and the practicabilityof the separation method for direct radiated noises of propellers from the vibration soundradiations of shells excited by propellers are proved; further more, the correctness of theseparation method for ship propeller is verified by means of comparative analysis on directradiated noise separation results of ship propulsion and relevant model test results.更多还原