Hydrodynamic Performance Analysis For Rim Driving's Pump-jet Thruster

Blade shround propeller is a novel propeller without traditional blade tip and hub.It add motor inside its duct,transforming axial driving into radial driving.It has better transmission efficiency,better flow,less cavitation,less vortex and many other advance.As the preferred of the current advanced submarine propulsion equipment,pump-jet propulsion owns excellent noise performance and propulsion performance.The study about these two thrusters is relatively few at home and abroad,especially rim propeller.As the structure reasonable,supposing that combining the advantages of the two propellers to design a new propeller named rim driving's pump-jet thruster is possible,it is significant to study the new propeller.First of all,the ICEM software was used to dividing mesh for blade shround propeller,and the hydrodynamic performance of the propeller was calculated and discussed.Results show that the vortex was less from the flow field,but the more torque from the rim,so the efficiency was not very good.Then the blade parameters were changed to do more analysis,it showed that pitch distribution and rim torque had a significant influence on hydrodynamic performance of blade shround propeller,the other parameters almost had no effects for hydrodynamic performance.At the same time,a kind of blade shround propeller owns equal thrust both forward spinning and backward spinning which may be widely used was proposed on the foundation of the variable parameter analysis.Next,the hydrodynamic performance of pump-jet thruster was analyzed that the research shows the front stator can bring a beneficial effect to flow field which greatly improve hydrodynamic performance for pump-jet thruster if the stator and rotor matching properly.Finally,according to analysis results about the hydrodynamic performance of the two kinds of propellers and the feasibility of the structure,while adjusting the blade parameters that a new style special propeller was designed to transforming hub driving into rim driving to instead of pump-jet thruster which named rim driving's pump-jet thruster.After comparing pump-jet thruster with rim driving's pump-jet thruster on the hydrodynamic performance,the optimization of rim driving's pump-jet thruster was provided,and the no cavitation noise performance was analysed,the analysis of the Directivity of Noise was compared with pump-jet thruster.