Numerical Modeling of Helical External Gear Pump Through a Novel CFD Approach Using Simerics MP+

External Gear Pumps (EGPs) are positive displacement machines with excellent performances and very competitive costs. A particular typology of EGPs is Helical Gear Pump, where the teeth present an inclination along the axial direction, permitting a progressive meshing with consequent lower vibration and noise emission. Three-dimensional CFD numerical analysis of these pumps has proven to be quite complex. More recently some analyses have been proposed however, to obtain realistic results, approximations regarding the helical angle along the axial dimension have been applied. Those models consisted of a high number of grid cells, leading to high computational time request. In this article, it is explored the use of a novel CFD approach through the use of the commercial code Simerics MP+, already used with success by the research group. This new method permits to evaluate the geometry of the pump without any geometrical approximation, leading to more accurate results and less computational time required if compared with other 3D-CFD tools. An accurate numerical model has been built up on a reference pump with helical gears; the model has been then compared with the results of an experimental campaign. Finally, a new design of the pressure relief grooves inside the wear plates has been investigated and simulated with the objective of reducing the fluid-borne noise emission, as well as to improve the volumetric efficiency of the pump and to reduce the flow ripple fluctuation, pressure spikes and crossflow optimization.