波流耦合作用下航行体出水空泡的非稳态特性和机理及流动控制方法

In the water-exit process of the submerged vehicle with attached cavity, the hydrodynamic forces caused by the collapse of cavity will significantly affect the attitude and structural strength of the vehicle. The strongly nonlinear effect in wave-current interaction makes the instability behavior of cavity to be more complicated. It's urgent for the water-exit research of submarine-launched weapon that, the characteristics and mechanism of the unstable cavity with wave-current coupling effect should be well studied, and proper flow control methods should be proposed to restrain or adjust the loads caused by cavitation collapse. In the present project, varieties of wave-current states will be used to construct the numerical wave-current flume based on the nonlinear waves in deep sea. The numerical simulations in multiphase model framework and appropriate amount of mechanism experiments will be carried out, to investigate the property and mechanism of the unstable cavity during water-exit in the different cases of same direction, reverse direction and inclined intersection of the wave and current. The influence of various factors on the results will be analyzed, such as the wave-current coupling state, wave elements, current parameters, navigation speed, angle of attack or inclination, and so on. Afterwards we will utilize several kinds of flow control methods, such as blowing on wall, boundary layer suction and artificial ventilation, to control the cavitating flow during water-exit and investigate their effects in restraining the collapse impact. We will attempt to find the quantitative relation between the restraining effectiveness and the flow control parameters, and will establish the criterion for choosing the optimal controling parameters according to the different wave-current parameters and motion parameters of the vehicle.

在水下航行体带空泡出水过程中，空泡溃灭造成的水动力载荷严重影响航行体的出水姿态和结构强度。波浪与海流共同作用的强非线性使出水空泡的非稳态行为变得更加复杂。研究波流耦合条件下的空泡非稳态特性和机理，并提出有针对性的流动控制方法以抑制或调节溃灭载荷，是潜射武器出水问题研究的当务之急。本项目将针对不同的波浪和海流状况，构造基于深水非线性波的数值波流水池，采用多相流数值模拟方法并结合机理试验，对波流同向、逆向和斜交等各种耦合条件下的航行体出水空泡非稳态特性和机理进行细致的研究，并对耦合状态、波浪要素、海流参数、出水速度以及攻角和倾角等进行多因素影响分析。在此基础上，我们引入壁面喷吹、边界层抽吸和人工通气等多种方法用于出水空泡的流动控制，研究其在抑制空泡和缓解溃灭载荷方面的作用，形成空泡调控效果与流动控制参数之间的定量化关系，并建立起根据不同的波流参数和运动参数确定最优化控制参数的准则。

在水下航行体带空泡出水过程中，空泡溃灭造成的水动力载荷严重影响航行体的出水姿态和结构强度。波浪与海流共同作用的强非线性使出水空泡的非稳态行为变得更加复杂。研究波流耦合条件下的空泡非稳态特性和机理是潜射武器出水问题研究的当务之急。本项目针对不同的波浪和海流状况，基于深水非线性波构造了几种波流同向、逆向的数值波流水池。采用多相流数值模拟方法，结合湍流建模、空化模型、界面捕捉方法和动网格技术等，对多种波流耦合条件下的航行体出水空泡非稳态特性和机理进行细致的研究，对波流耦合状态、波浪要素、海流参数、出水速度、出水攻角和出水倾角等进行多因素影响分析，掌握了这些因素在航行体出水空泡演变过程中的作用。通过对这些多种不同因素作用下的空泡流动结构的分析，我们获得了对航行体发射出水过程中的非稳态空泡动力学特性和流动机理的深入认识。