高速航行体附着空泡溃灭载荷计算及实验方法研究

Instantaneous high pressure generated by collapse jet of bubble attached high speed vehicle , not only is the cause of cavitation erosion of ship and submarine propeller , especially in the submarine launched missile underwater out-water instantly. Attached high-frequency transient strong nonlinear impact load by bubble collapse, will greatly change the hydrodynamic distribution of projectile...The present study for bubble collapse load calculation in one of the important parameter -the jet impact compression wave velocity, which ignored the gas and water content with different changes will lead impact load calculated values to appear too large situation. ..Therefore, this project intends to start from the physical process of attached cavitation bubble collapse with couple method of the potential flow boundary element method and finite element method to build the three-dimensional mechanical model of attachment bubble collapse. Mechanical model and calculation method with the compression wave velocity variation of the attached bubble considered are derived. Analyze the influence law of different gas content model for jet shock load characteristic. Design attached bubble out-water test device. Experimental studies focus on the development of cavitation water collapse load characteristics. To explore motion characteristics of the vehicle attached bubble and the dynamic behavior and the influence rules of vehicle motion. In order to reveal the attached cavitation out-water collapse mechanism and the research methods of attached bubble collapse impact and to provide the support of basic theory for studying the attached bubble collapse impact problem.

高速航行体附着空泡溃灭射流产生瞬时高压载荷，不仅是船舶和潜艇螺旋桨叶产生空蚀的诱因，尤其在潜射导弹水下发射出水瞬间，附着空泡溃灭形成的高频瞬态冲击载荷呈现强非线性，将会极大地改变弹体水动力分布。目前研究中对于空泡溃灭载荷计算中重要的参数之一——射流冲击压缩波速度，忽略了其随气水含量不同的变化而出现冲击载荷计算值出现过大的情况。为此，本项目拟从附着空泡溃灭的物理过程入手，将势流边界元方法和有限元法耦合建立附着空泡溃灭的三维力学模型；推导并建立考虑压缩波速度变化的附着空泡射流冲击的力学模型及计算方法；分析不同含气量模式对射流冲击载荷特性的影响规律；设计附着空泡非定常出水试验装置，开展空泡出水溃灭载荷特性的实验研究，探索附着于航行体上空泡的运动特性和动力学行为及其对航行体运动的影响规律。旨在揭示附着空泡非定常出水溃灭冲击的机理和研究方法，为该类附着空泡溃灭冲击问题的研究提供基础性理论支撑。

本研究针对水下高速航行体附着空泡在水中运动及出水瞬间溃灭产生的射流冲击问题，计入表面张力的影响，考虑射流冲击含气量对压缩波速度的影响，基于流体动力学理论和边界元方法，建立了附着空泡运动阶段和射流冲击阶段的力学模型和数值模型，将两种计算方法相耦合，形成一套三维附着空泡溃灭载荷的计算方法。在此基础上，着重分析含气量模式对于射流冲击载荷特性的影响规律，在已有实验技术基础上设计附着空泡非定常出水实验装置，开展空泡出水溃灭载荷特性的实验研究，旨在揭示附着空泡非定常水空泡溃灭冲击机理，可为该类附着空泡溃灭冲击问题的研究提供基础性理论支撑。