SIMULATION OF AN EXTERNAL GEAR PUMP AND EXPERIMENTAL VERIFICATION

Abstract

A detailed simulation program is presented for investigating the performances of an external gear pump. The geometrical aspects and the differential equations representing the quasi-steady state mathematical model of the pump are accounted for and discussed. Initial conditions are determined accordingly to a new proposed method and numerical aspects bound to the solution of the stiff ODE system are addressed. Experimental data generated on a commercially available medium size external gear pump were used to validate the model predictions. Agreement between experimental and predicted values of pump performances was satisfactory. Being the model unable to simulate pressure ripples generated by the unsteady nature of the flow within volumes and along the lines, several experimental results of inlet pressure fluctuations are reported. Predicted and unpredicted fluid borne noise sources are hence accounted. Finally, the influence exerted on the operation of the pump by pressure forces and forces exchanged between meshing teeth is investigated and a predictive method foreseen (useful in condition monitoring) based on the observation of outlet pressure waveforms.