近刚性圆柱水下爆炸气泡动力学特性研究

针对刚性圆柱附近水下爆炸气泡的动力学特性进行了研究. 基于Navier-Stokes方程结合流体体积法捕捉气液两相界面，建立了数值模型；采用电容器放电产生水下爆炸气泡并用高速摄像机记录了气泡的脉动，并将实验结果与数值模拟结果对比验证了数值模型有效性. 通过数值模拟得到了气泡与刚性圆柱相互作用的流场细节信息. 结果表明:气泡在刚性圆柱附近脉动使得刚性圆柱表面流体介质存在速度梯度，速度较大的流体液层冲击气泡形成不同的气泡形状. 定义了一个量纲一的距离参数来表征气泡与刚性圆柱之间的相对距离，研究了距离参数对射流冲击压力、最大射流速度及气泡型心运动的影响. 随着距离参数的增大，射流冲击压力逐渐减小，气泡内部最大射流速度先增大后减小；气泡型心的偏移随距离参数的增加而减小. 

Dynamic Characteristics of Underwater Explosion Bubble near Rigid Cylinder

To study the dynamic characteristics of underwater explosion bubbles near a rigid cylinder, a numerical model was established based on the Navier-Stokes equation combined with the volume of fluid method (VOF) to capture the gas-liquid two-phase interface, Using capacitor discharge to generate underwater explosion bubbles and using a high-speed camera to record the pulsation of the bubbles, some experiments were carried out. The experimental results were compared with the numerical simulation results to verify the validity of the numerical model. The numerical simulation results provide detailed information of the flow field of the interaction between the bubble and the rigid cylinder. The results show that the bubble pulsates near the rigid cylinder can make the fluid medium on the surface of the rigid cylinder form a velocity gradient, and the fluid layer with higher velocity can make the bubble form different bubble shapes. Finally, a dimensionless parameter was defined to characterize the relative distance between the bubble and the rigid cylinder, and the influence of the distance parameter on jet impact pressure, maximum jet velocity and bubble core movement was studied. The results show that, with the increase of the distance parameter, the jet impact pressure gradually decreases, and the maximum jet velocity inside the bubble increases first and then decreases, the deviation of the bubble core decreases with the increase of the distance parameter.