运动参数对回转体倾斜入水流场特性影响

Influence of motion parameters on the flow field characteristics of revolution body with oblique water-entry

为分析回转体低速倾斜入水过程中入水空泡形态及流体动力特性演化规律,基于Fluent流体计算平台,并利用动网格技术,针对小型回转体以不同入水速度和入水角度的倾斜入水过程开展数值仿真研究.数值仿真结果与试验结果良好一致性,证明了文中数值仿真方法的正确性与有效性.基于该数值仿真方法,针对不同入水速度和不同入水角度回转体低速倾斜入水过程流场特性进行分析.数值计算结果表明:在距离自由液面相同位置处,回转体倾斜入水产生所产生的入水空泡,其直径随着入水速度的增加而小幅增大,随着入水角度的增加而减小;入水速度对流场中压力分布规律有较大影响,在同一入水深度处不同入水速度回转体入水过程中流场的最大压力随着入水速度的增加而增大;入水角度对回转体附近流域的最大压力影响较小,但最小压力随着回转体入水角度的增加而增大;不同入水角度回转体,母线压力峰值位置随着入水角度的增加而逐渐向母线右端点偏移,但其值差别较小;不同入水速度回转体其阻力系数峰值差别不大,不同入水角度阻力系数峰值随着入水角度的增加而增大,但稳定后的阻力系数值随着入水速度的增加而减小.

To investigate the water-entry cavity and the dynamic characteristics of the revolution body,the Fluent was adopted for the multiphase flow and the movement of the water-entry revolution body with the dynamic mesh.The effectiveness of the numerical method was verified by comparing the numerical results with the experimental results.Based on the method,the flow field characteristics during the oblique water entry of the revolution body with different velocities and angles is studied.Results show that in the same water depth,the diameters of the water-entry cavity increased slightly as the velocity of water entry increased,and decreased as the angle of water entry increased.The velocity of water entry had a great influence on the pressure distribution in the flow field.The maximum pressure of the flow field increased as the water-entry velocity increased for the same water depth.The angle of water entry had little influence on the maximum pressure of the flow field near the revolution body,but the minimum pressure increased as the water entry angle increased.When the angle of the water entry was larger,the point of the maximum pressure in the generatrix of the cone shifted to the right endpoint gradually,but its value had little difference.The drag coefficient peak value differed slightly with increasing the velocity of water entry,but became larger as the angle of water entry increased.The stable drag coefficient became larger with the increase of water-entry velocity.