A Numerical Model for the Simulation of Flow in Hydraulic External Gear Machines

The present paper describes a numerical model, developed by the authors, for the simulation of external gear pumps. The model has been implemented in AMESim® environment, developing new in-house C++ models. The fluid dynamic model is based on a finite volume framework. The pump is described with a geometrical sub-model, which yields the actual values of the variable volumes (defined by teeth, housing, and side wear plates) and of the throat areas, as functions of shaft position. The model allows to predict the pressure evolution inside each tooth space, while considering cavitation and leakages in a simple manner. After pressure inside each tooth space is known, the forces suffered by the gears and the torque required to drive the pump are determined. The results have been verified through comparisons with some experimental data