水下机器人逆向运动时导管螺旋桨推力特性的模拟

Simulation of Hydrodynamics of Underwater Robot in Reverse Propeller and Negative Speed

采用动网格和滑移网格混合技术,运用弹簧光顺和局部网格重构的组合式网格更新方式,在水下机器人系统所处流域以计算流体力学方法求解其N-S方程。数值计算结果表明:采用动网格和滑移网格混合技术模拟水下机器人系统水动力是可以获得正确结果的;水下机器人系统在逆向运动、螺旋桨反转时,由于主体对水流的阻塞作用和外扩作用,使得后桨、左桨和右桨所处区域的水流轴向速度偏小,造成后桨、左桨和右桨所发出的推力都较单桨大。

Using CFD methods, the N-S equation in the watershed where the underwater robot system is located is solved based on hybrid technique of dynamic mesh and sliding mesh, mesh renewal method for spring smoothing and local mesh reconstruction. Numerical results indicate that it can obtain the correct result by using hybrid technique of dynamic mesh and sliding mesh to simulating the hydrodynamics of the underwater robotic system. Under the negative speed and when the propeller reverses, the axial flow velocity is too small in the area of back propeller, left propeller and right propeller because of the main body's blocking effect and external expansion to water, which causes larger thrust of back propeller, left propeller and right propeller comparing with the single propeller.