航行体水下发射流固耦合效应分析

发布时间：2019-05-18 15:13

【摘要】：对于水下发射过程来说,掌握水动力载荷形成机理与结构响应特征是一个亟待解决的问题.研究该问题需要考虑含相变的复杂多相流动,变约束的结构运动以及这二者之间的耦合效应.本文采用松耦合的方法,以流体求解器为主体,将自编的固体结构程序接入流体求解器中,在每个时间步长内分别对流体动力学方程和固体结构动力学方程进行求解,通过流固界面之间的数据交换实现耦合计算.其中,流体求解器基于雷诺平均纳维斯托克斯方程,采用单流体模型处理多相流问题,引入空化模型描述空化相变,采用修正的湍流模型模拟混合物的湍流效应,并采用动网格技术处理移动边界问题.航行体的刚体运动和结构振动分开求解.结构求解器采用等效梁模型描述结构的振动,通过坐标变换给出了随体坐标系下的结构振动方程,求解方法采用时域积分法.所建立的流固耦合方法不仅能够捕捉到自然空化的演化情况,还可获得航行体所受水动力、结构振动响应以及截面的弯矩,获得了实验的验证.基于该方法研究了结构刚度、发射速度对空泡溃灭与结构振动耦合效应的影响规律.结果表明,同步溃灭是影响结构载荷的主要因素,包括溃灭压力幅值,溃灭压力作用位置,以及溃灭压力与结构振动的相位关系.
[Abstract]:For underwater launch process, mastering the formation mechanism of hydrodynamic load and structural response characteristics is an urgent problem to be solved. In order to study this problem, it is necessary to consider the complex multiphase flow with phase transition, the structural motion with variable constraints and the coupling effect between the two. In this paper, with the fluid solver as the main body, the self-designed solid structure program is connected into the fluid solver by using the loose coupling method, and the hydrodynamic equation and the solid structure dynamic equation are solved respectively in each time step. Coupling calculation is realized by data exchange between fluid-solid interfaces. The fluid solver is based on the Reynolds average Neville equation, uses a single fluid model to deal with the multiphase flow problem, introduces the cavitation model to describe the cavitation phase transition, and uses the modified turbulence model to simulate the turbulent effect of the mixture. The moving grid technology is used to deal with the moving boundary problem. The rigid body motion and structural vibration of the navigational body are solved separately. The equivalent beam model is used to describe the vibration of the structure. The vibration equation of the structure in the body coordinate system is given by coordinate transformation. The time domain integration method is used to solve the problem. The fluid-solid coupling method can not only capture the evolution of natural cavitation, but also obtain the hydrodynamic force, structural vibration response and section bending moment of the navigational body, which is verified by experiments. Based on this method, the effects of structural stiffness and emission velocity on the coupling effect of cavitation collapse and structural vibration are studied. The results show that synchronous collapse is the main factor affecting the structural load, including the amplitude of collapse pressure, the position of collapse pressure, and the phase relationship between collapse pressure and structural vibration.
【作者单位】：中国科学院力学研究所流固耦合系统力学重点实验室;中国科学院大学工程科学学院;
【基金】：国家自然科学基金资助项目(11402276)
【分类号】：O353.4

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