Research On Hydrodynamic Characteristics Of Submarine Yaw Movement Machine Under Various Navigation Conditions

With the development of science and technology,people explore more and more seafloor and lake,so underwater exploration tools such as submersible have been paid more and more attention by scholars at home and abroad.The research on submarine motion at home and abroad mainly focuses on dynamic characteristics and motion state.Underwater submarine has a large number of plane yaw motion while sailing,and the realization of these movements is based on accurate dynamic parameters.In this paper,the yaw motion of the pump jet thruster is calculated by using the RNG k-? turbulence model,taking the spiral mixed flow pump jet thruster as the research object.In order to study the dynamic characteristics of the submersible under different motion forms,the relationship between the yaw angle and the force of the submersible is obtained by changing the yaw angle of the submersible,and then the variation law of the dynamic parameters under different direct navigation acceleration is compared and analyzed;secondly,the force characteristics of the pump jet thruster under different yaw motion are calculated and analyzed by changing the number of tail rudder angles.The main conclusions of this paper are as follows:The main results are as follows:(1)the force characteristics of the pump jet propulsion submersible at different yaw angles are analyzed.the results show that when the speed of the thruster is certain,that is,when the Reynolds number is in the square area of resistance,the resistance coefficient does not change with the increase of yaw angle.The lateral force is proportional to the yaw angle,and the lift is inversely proportional to the yaw angle.(2)By sliding grid technology,the operation of submersible is simulated in a certain time step.The calculation results show that with the movement of the submersible along the Z axis,the high speed range of the outer surface of the submersible decreases,and the negative pressure range of the tail increases,and the low speed range near the surface of the submersible command platform increases.(3)Through the study of the yaw dynamic characteristics of the pump jet thruster under different working conditions,it is found that the variation law of the resistance coefficient is similar to that of the direct navigation movement,and the rudder angle and speed are the main factors affecting the resistance characteristics of the pump jet thruster.When the rudder angle is 10 °,20 °and 30 °,the lateral force of the submersible is about 6 times,12 times and 16 times of the lateral force of 0 °rudder angle,respectively.At different speed stages,the influencing factors of resistance aredifferent.(4)The total thrust of the pump ejector increases with the speed close to the parabola,which indicates that the rotational speed is the direct factor affecting the total thrust,and the rotational speed,rudder angle and yaw angle directly affect the lateral force,and the increasing trend of the lateral force is positively correlated with the above three navigation conditions.