Three‐Dimensional Finite Element Modeling of a Viscous Fluid Flowing through an External Gear Pump

Abstract

An external gear pump is a relatively simple and inexpensive pump, that is used in a variety of production systems. Numerous works have studied the external gear pump using numerical simulations; however, typically low-viscosity fluids and turbulent flow conditions are considered. Previous work of the authors focused on predicting the output fluctuation and the volumetric efficiency of an external gear pump processing high-viscosity fluids using a 2D representation. For certain conditions, backflow through all clearances could occur, resulting in a drop in volumetric efficiency. This calls for a full 3D model. Furthermore, high residence time zones are observed in the inflow channel of the pump. The 3D shape of these zones is still unknown. The aim of this work is to investigate the effect of the axial clearances on the performance of the external gear pump. A 3D mesh is generated by extruding the 2D mesh in the third direction, resulting in prism elements. This reduces the required number of elements and therewith makes the simulations computationally feasible. Introducing the axial clearances results in a lower efficiency compared to the 2D simulations. With particle tracking, the high residence time zones in the inflow channel are visualized in the 3D simulations.

The Effect of Non-Newtonian Behavior on Contact Formation in an External Gear Pump

“…In previous studies of the authors [4,7], finite element simulations of an external gear pump are developed with the rotation of both gears imposed. A fluctuation of the output, i.e.…”

The extrusion of EPDM using an external gear pump: experiments and simulations

“…In previous work (de Bie et al 2021Bie et al , 2022a, numerical simulations of an external gear pump are developed for shear-thinning fluids. The effects of decreasing the rotation speed of the gears, decreasing the viscosity of the fluid or increasing the pressure difference over the pump on the output of the gear pump were similar; they all eventually resulted in a lower flow rate.…”

“…The drop in efficiency is faster, i.e. in a smaller range of the Hersey number, for more shear-thinning fluids (de Bie et al 2021Bie et al , 2022a.…”

“…In this work, the flow of polymer melts (EPDMs) through an external gear pump is numerically studied using the finite element method (FEM). A two-dimensional representation of a commercial pump is used, since we observed earlier (de Bie et al 2022a) that most leakage is present in the radial clearances. The rotation of both gears is imposed, since this seemed to be a valid assumption for rubbers (de Bie et al 2022b).…”