Research On Thrust Characteristics Of A Underwater Vehicle's Rotational Motion Using The Technique Of Dynamic Mesh And Cavitation Model

By using the technique of dynamic layering of dynamic mesh,the open water test of ducted propeller was simulated and analyzed by computational fluid dynamics,with the cavitation simulated caused by the high rotational speed of the propeller.Zwart-Gerber-Belamri model was used as cavitation model.And the sliding mesh was used to simulate the rotational motion of ducted propeller,while the dynamic layering of dynamic mesh was used to simulate the rectilinear motion of ducted propeller.The layering of dynamic mesh was simple,with small error.When the underwater vehicle motioned in the water,the rectilinear motion was not only considered,the rotational motion and some other complex forms of motion fit the motions of underwater vehicle.When the dynamic mesh was used to simulate the process of underwater vehicle's motion,the UDF was used to define and control the forms of motion.In this paper,the mathematical model of rotational motion of the system of underwater vehicle was analyzed,with UDF to define the forms of motion,the characteristic of thrust was dynamically simulated when the underwater vehicle motioned rotationally.When the underwater vehicle motioned in the water,a number of cavitation bubble was generated because of the high speed of propeller's rotation,which made the characteristic of thrust change,the cavitation of propeller could be simulated by the model of cavitation,with sliding mesh and dynamic mesh,the process of rotational motion of underwater vehicle could be simulated.The calculation results shows that: In the simulation of the open water test of propeller,the cavitation bubble influenced the results of the propeller's thrust,the generation of cavitation bubble changed the distribution mode of the vortex around the propeller.The simulation of underwater vehicle's rotational motion made the flow field changed massively,while the thrust of propeller tended to stable change periodically.The incoming flow and mainbody of vehicle made the thrusts different generated from two sides of the propellers.But the amplitude of the two propellers' thrust equaled.