摘要: |
为研究船舶桨轴舵及船体艉部耦合振动噪声特性,将CFD整体计算得到的非定常力作为激励源,以分布载荷的形式加载于有限元模型上,并结合模态叠加法和声学边界元法建立了桨轴舵及船体艉部耦合振动噪声的数值计算方法。通过分析振动响应计算结果,发现频率较低时耦合系统振动响应受工况影响比频率较高时更加明显;振动响应最大幅值所在频率受结构特性和激励源的共同影响;在桨-轴系统中,桨叶的振动传递损失最大。通过对比不同模型的桨叶振动计算结果,发现桨-轴系统模型的计算值与桨-轴-船系统模型更为接近且不复杂,比单桨模型更为实用。通过分析振动噪声计算结果,发现振动响应频谱和声场分布均可反映结构的固有特性;船体振动贡献的总声压在耦合系统中占90%以上,而桨叶振动仅为1%左右,在预报螺旋桨引起的振动噪声时,需要将船体振动噪声考虑在内。 |
关键词: 螺旋桨 振动 噪声 CFD 有限元 模态叠加法 边界元 |
DOI:10.13675/j.cnki.tjjs.190328 |
分类号:U661.31 |
基金项目:国家自然科学基金(51179198)。 |
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Numerical Study on Ship Propeller-Shaft-Rudder-Stern Coupled Vibration Noise |
XU Ye1, XIONG Ying1, HUANG Zheng1
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College of Naval Architecture and Ocean,Naval University of Engineering,Wuhan 430033,China
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Abstract: |
To study characteristics of ship propeller-shaft-rudder-stern coupled vibration noise,unsteady force derived from integral CFD calculation was used as excitation force,and loaded to finite element model in the form of distributed load. Combined with modal superposition and acoustic boundary element method,a numerical method to calculate propeller-shaft-rudder and stern coupled vibration noise was established.The analysis of vibration response results illustrates that the influence of working condition to vibration response is more obvious in lower-frequency spectrum than that in higher-frequency spectrum. Frequency of the maximum vibration response amplitude is influenced by structure characteristics and excitation resource. Propeller blade has the maximum vibration transmission loss in propeller-shaft system.The comparison of different model’s propeller blade vibration results illustrates that propeller-shaft model is more practical than single propeller model because of its closer results to propeller-shaft-hull model and simplicity.The analysis of vibration noise results illustrates that vibration characteristics can be reflected by frequency spectrum of vibration response and sound field distribution. Total sound pressure contributed by hull vibration accounts for above 90% while that of propeller blade is only about 1%,therefore vibration noise of hull should be considered when predicting propeller induced vibration noise. |
Key words: Propeller Vibration Noise CFD Finite element Modal superposition method Boundary element |