Research On Flow Characteristics And Structure Optimization Of Small-scale Shaftless Hydraulic Propeller

The shaftless hydraulic propeller is a new type of ship propulsion system proposed in recent years.It is characterized by the elimination of the transmission shaft and the direct integration of the motor and propulsion into one,making it more compact and noise-reducing.advantage.In the military and civilian fields have received a high degree of attention,and the propulsion system has now been applied to our latest generation of nuclear submarines.In the future,the development trend of water-jet propulsion devices will develop in the direction of miniaturization,modularization,and integration,which will provide even more power for small vessels.In order to improve the power performance of small water jet propulsion,this paper presents a new type of small shaftless hydraulic propeller.By replacing the original shaft drive method with the original small water jet thruster,the shaftless blades are replaced with rim blades,and the inner rotor brushless motor directly drives the propeller.The blade,instead of the original engine,drives the propeller through a propeller shaft.By referring to the original shape of a small hydraulic propeller,and then using the three-dimensional software Solidworks to create a fluid computation model for the entire propeller,a digital model of a new non-axis hydraulic propeller was made based on this model.Commercial CFD software was used to numerically simulate thrust and efficiency of the improved model and the improved model.The comparative analysis shows that the small-sized shaftless hydraulic propeller adopting the new structure adopts rim blades to eliminate the transmission shaft and reduce the disturbance of the non-uniform inflow on the velocity field of the hydraulic propeller,thus enhancing the fluidity of the blade.The efficiency of work and the ability to pass fluids increase the propulsion performance of the thruster.Under optimal conditions,the thrust increases by 9%.Therefore,in the field of small propellers,the new shaftless waterjet thrusters involved in this paper are structurally feasible and have advantages in hydrodynamic characteristics.They can be applied to military operations,and can also be applied to civil entertainment fields such as power surfing.Boards,motor boats,etc.This study provides direction for the miniaturization of waterless thrusters.