Simulation and Analysis for the Flow Field Inside External Gear Pump

To catch the instantaneous variation of fluid field inside of the external gear pump in the high speed rotating process,a certain type of actual gear pump model was researched. Using the moving grid technology of CFD software FLUENT,the two-dimensional internal fluid field of the gear pump was stimulated. Transient internal pressure field and velocity field distribution during the normal working process of the gear pump were gotten. The import and export instantaneous flow rates were gained which were compared with theory mean flow rates. The results show that during the meshing process of the two gears,the trapped oil pressure can be increased to the dozens of times of the working pressure,oil is extruded at a high speed from the both side of the gears,and is leaked from the radial clearance. These calculation results provide a theoretical basis for the optimization design of the external gear pump.