船舶螺旋桨空化噪声非均匀调制特性及其应用

Non-uniform modulation feature of ship propeller cavitation noiseand its application

从螺旋桨空化噪声谱统计模型出发,分析研究螺旋桨空化噪声非均匀调制特性的机理和规律,并利用大量海上实录船舶噪声进行验证。从形成机理看,认为非均匀调制特性主要由船尾形状、螺旋桨结构以及船舶航行工况共同决定的尾流分布所导致,不同型号船舶的非均匀调制特性具有个体性;从舰船噪声信号能量谱看,调制的非均匀特性,主要受能量谱峰值频率的影响。最后基于船舶噪声的非均匀调制特性,提出一种基于多子带自适应加权的DEMON增强算法,并利用实际数据进行验证。

Based on the statistical model of ship propeller cavitation noise spectrum, the mechanism and laws of nonuniform modulation feature of propeller cavitation noise are analyzed and studied, and also be verified by a large number of ship radiated noise. From thepoint of formed mechanism, it shows that non-uniform modulation feature is mainly formed by the distribution of wake flow, which is formed by the combined action of stern shape, propeller structure and working condition. Non-uniform modulation feature vary in different class ship. Then from the point of ship radiated noise spectrum, nonuniform modulation feature is mainly decided by the energy spectrum peak frequency. Finally, an application method of nonuniformity envelope is proposed, that is the technology of DEMON line spectrum strength based on multi sub-band adaptive weighted, and it is also verified by real date.