Analysis Of Vibration Characteristics Of Submarine Non-pressure Hull And Typical Structure

As one of the most important weapons in our country,the performance of submarine will be directly related to the security of national defense.Submarine will make noise when cruising underwater.The magnitude of noise directly affects the concealment of submarine.In order to reduce the noise,it is necessary to reduce the vibration of the submarine.Before that,many researchers have done a lot of vibration research on submarine’s pressure hull and shafting structure.However,the vibration of non-pressure hull and its typical structure is rarely mentioned.Therefore,it is of great significance to analyze the vibration of submarine’s nonpressure hull and its related structures.This paper mainly takes the submarine’s non-pressure hull and typical structures(fairwater,superstructure and stern wing)as the research object,uses ANSYS Workbench and Fluent for joint simulation,and analyzes the submarine’s dry mode and wet mode,bi-directional fluidstructure interaction,unidirectional fluid-structure interaction and flow noise.The specific work is as follows:Based on ANSYS Workbench platform,the dry mode of submarine’s overall structure and typical structure(fairwater,superstructure and stern wing)are calculated by Block Lanczos method,and the wet mode of submarine’s overall structure and typical structure are calculated by Unsymmetric method;The influence of submarine’s non-pressure hull thickness on submarine’s dry mode and wet mode and the influence of diving depth on submarine’s wet mode are studied.The results show that the dry mode frequency and wet mode frequency of submarine increases with the increase of shell thickness,and the wet mode frequency decreases with the increase of diving depth.Based on ANSYS Workbench platform and fluid analysis software Fluent,the numerical simulation of the bi-directional fluid-structure interaction of submarine and the unidirectional fluid-structure interaction of submarine’s fairwater and superstructure and stern wing was carried out;The effects of submarine’s speed and thickness of submarine’s non-pressure hull on the vibration of the whole submarine and the effects of submarine’s speed and thickness of submarine’s non-pressure hull on the vibration of typical submarine’s structures are studied.The results show that the vibration displacement,vibration velocity and vibration acceleration of submarine increase with the increase of speed and decrease with the increase of hull thickness.Based on the FWH equation in Fluent,the flow noise of the whole submarine,fairwater,superstructure and stern wing is numerically simulated;The distribution law of submarine’s flow noise in X,Y and Z direction is studied,and the influence law of speed on the flow noise of the whole submarine and typical structure is explored.The results show that the flow noise increases with the increase of speed,and the greater the distance from the submarine’s surface,the smaller the flow noise.