Study On Cavitation Mechanism And Influence Factors Of Water Gear Pump

Water gear pump is one of the most important power components in the hydraulic circuit.Its structure is simple,environmental protection,and maintenance is convenient.It will be widely applied in food processing and medical industry.But because of widespread water pump cavitation in the water,there are a lot of bubbles,when the bubble collapse caused by continuous wall impact,will produce cavitation damage fracture or fatigue,pitting occurs on tooth surface and cavity wall.Therefore,it has important theoretical and engineering application value to study the cavitation mechanism and influence factors of the water gear pump.In this paper the fluid mass conservation equation,momentum conservation equation,energy conservation equation on the basis of a full cavitation model;through the C language update method to establish the dynamic mesh model and UDF procedures prescribed row grid;cavitation flow simulation accuracy,built model can realize vertical turbulent two equation model;calculation and given the gear pump inlet pressure and pressure loss of the oral cavity.The theoretical basis is provided for the numerical simulation of the cavitation of the water gear pump.CB-B25 type gear pump as the research object,the geometric model is set up,using structured and unstructured meshes are combinations of the mixed grid;combined with the full cavitation model,transient numerical simulation model of water pump in fluid field,numerical simulation for calculating the instantaneous pressure,instantaneous phase,instantaneous gas flow provides the conditions.In order to study the cavitation mechanism and influencing factors of water gear pump,numerical simulation of cavitation gas holdup and flow characteristics of water gear pump was carried out by taking the factors such as pump suction diameter,cavitation in inlet pipeline,circulating water temperature and outlet load as variables.The relationship between the above factors and the cavitation effect in the gear pump is obtained,and the relationship between the above factors and the outlet pressure or flow fluctuation is provided,which provides a solution for cavitation suppression of the water gear pump.Aiming at the above numerical simulation results,this paper takes the amplitude of output pressure fluctuation of the gear pump as the evaluation standard,and builds the experimental platform of the main components of the water gear pump,the pressure sensor,the throttle valve and the relief valve.The experimental platform,by changing the diameter of the suction pipe,adjusting the opening area of the inlet throttle valve,controlling the water temperature of the tank and adjusting the outlet relief valve,collects the pressure fluctuation curve of the pump outlet to verify the accuracy of the numerical simulation.The numerical simulation method based on full cavitation model and dynamic mesh model is provided in this paper,which provides a basis for cavitation suppression of water gear pump,and is of great significance for studying the application of water gear pump.