Influence Of Geometric Parameters Of Space Space Guide Vane On A Water-Jet Screw Mixed-Flow Pump

The ship's power system is the most important research of all marine power.In recent years,the research and application of water jet pump have made great progress.In this paper,the current research status of water jet propulsion pump in various countries in the world is analyzed,and a new type of water jet propulsion pump,Water-Jet Screw Mixed-Flow Pump,is designed.Based on the existing submersible model,the resistance of the underwater submersible at v=2m/s is calculated by numerical calculation.And according to the existing water jet propulsion theory to determine the water pump flow and head.Then,the design of water-jet propulsion pump is carried out by referring to the design method of screw centrifugal pump.The RNG k-? turbulence model is selected to verify the performance of the water-jet propulsion pump.Subsequently,aimed at the problem of large hydraulic loss in space space guide vane.we studied the geometric parameters of space guide vane,including the number of space guide vane blades,intake angle and blade wrap angle,on the performance and internal flow of the helical mixed flow jet pump,and obtained the parameter range of the best hydraulic space guide vane.The relevant conclusions are as follows:1)Analysis of water-jet propulsion pump characteristics,internal flow and pressure fluctuation The propulsion pump meets the design requirements.Because the impact of the fluid in the impeller flow channel on the impeller wall surface leads to an increase in torque at 0.5Q,the input power is larger.The flow in the space guide vane flow passageway tends to be uniform with the increase of flow rate.Under the design condition,the dominant frequency of pressure fluctuation of each monitoring point in the propulsion pump passageway is at one frequency.The amplitude of pressure pulsation along the space guide vane passageway decreases first and then increases.2)The influence of the number of space guide vane blades on the performance of the water-jet propulsion pump There is a negative correlation between the total hydraulic loss and the number of leaves in the space guide vane and nozzle.When the number of space guide vane blades is greater than 5,the external characteristics of the water-jet propulsion pump no longer change.When the number of blades is 9,the absolute value of the circular rector at the exit of the blade is the smallest,and the rectification effect of the guide blade is the best.3)The effects of space guide vane's intake angle on water-jet propulsion pump's performance The intake angle of the space guide vane has significant influence on internal flow.With the increasing of intake angle,the vortex area of the connecting face between impeller and the space guide vane is enhanced.The region with higher turbulent kinetic energy increases firstly and then decreases,and moves from the inlet of blade back to the outlet.When the intake angle is 25°or 40°,the absolute value of outlet circulation is the minimum,space guide vane rectifying effect is the best.The hydraulic loss of the space guide vane and nozzle is the minimum when the intake angle is 30°-35°.The pressure pulsation amplitude on connecting face of rotor and stator is the smallest when the intake angle is 35°4)The effects of space guide vane's wrap angle on water-jet propulsion pump's performance Headway and efficiency of the water-jet propulsion pump are positively related to wrap angles.There is a negative correlation between the wrap angle and the total hydraulic loss in the space guide vane and nozzle.The streamlines of the space guide vane flow passageway gradually tend to rule with the increase of the wrap angle,and the area of the recirculation zone decreases.The region at inlet of blade back with higher turbulent kinetic energy decreases gradually with the increasing of wrap angle.The absolute value of outlet circulation increases firstly and then decreases with the increasing of wrap angle.When the wrap angle is 80°,space guide vane rectifying effect is the best.The pressure pulsation amplitude in space guide vane is the smallest when the wrap angle is 70°;the pressure pulsation amplitude of space guide vane outlet is the smallest when the wrap angle is 80°.