Numerical Experiment for Flow Characteristics and Cavitation Influence Factors of the External High Pressure Pump

In order to study the influence of flow pulsation coefficient on the internal flow field of the external helical gear high pressure pump, the influence of the helix angle on the flow pulsation coefficient is analyzed by the theoretical formula. Combined with computational fluid dynamics (CFD), the numerical experiment of the flow field in the external gear helical gear is carried out, and the influence of different speed and radial clearance on the pressure pulsation and flow characteristics was analyzed. The results show that when the flow pulsation coefficient is low, the flow field quality is higher and the gear pump leakage is smaller, the larger helix angle will reduce the flow pulsation coefficient and improve the quality of the outlet flow, the influence of speed on flow pulsation coefficient is larger and the average reduction rate is about 2.5%. The greater the rotational speed, the greater the change in pressure in the meshing area. When the speed and radial clearance increase, the leakage flow and leakage vortex intensity will be reduced. The study of the motion law and flow pulsation characteristics of the internal flow field of the high pressure pump has some reference value for the design and optimization of the external helical gear.