Study of a High-Pressure External Gear Pump with a Computational Fluid Dynamic Modeling Approach

Abstract

A study on the internal fluid dynamic of a high-pressure external gear pump is described in this paper. The pump has been analyzed with both numerical and experimental techniques. Starting from a geometry of the pump, a three-dimensional computational fluid dynamics (CFD) model has been built up using the commercial code PumpLinx ® . All leakages have been taken into account in order to estimate the volumetric efficiency of the pump. Then the pump has been tested on a test bench of Casappa S.p.A. Model results like the volumetric efficiency, absorbed torque, and outlet pressure ripple have been compared with the experimental data. The model has demonstrated the ability to predict with good accuracy the performance of the real pump. The CFD model has been also used to evaluate the effect on the pump performance of clearances in the meshing area. With the validated model the pressure inside the chambers of both driving and driven gears have been studied underlining cavitation in meshing fluid volume of the pump. For this reason, the model has been implemented in order to predict the cavitation phenomena. The analysis has allowed the detection of cavitating areas, especially at high rotation speeds and delivery pressure. Isosurfaces of the fluid volume have been colored as a function of the total gas fraction to underline where the cavitation occurs.

Evaluation of the Hydro—Mechanical Efficiency of External Gear Pumps

“…Moreover, del Campo et al [14,15] applied extensive CFD analysis and experimental measurements, focusing in particular on the study of cavitation and of the meshing process of external gear pumps. Cavitation in external gear pumps is a topic also improved by Edge et al in [16], Borghi et al in [17], and Frosina et al in [18], with different approaches, using in-house and commercial CFD code. Wang et al [19] applied the control volume approach, focusing on the analysis and optimization of the design of the machine to improve performance.…”

Pressure Pulsation and Cavitation Phenomena in a Micro-ORC System

“…The simulation strategy is based on a dynamic mesh approach, able to take into account the rotation and the engagement of the wheels, as well as the transient phenomena that affect the entire ORC. The dynamic mesh approach has been proven to be suitable for the analysis of such a machine, for discovering cavitation issues [17,18] and for calculating the performance [19,20].…”

Research into cavitation processes in the trapped volume of the gear pump

“…An effective technique to assess the volumetric efficiency of a high-pressure pump is the application of numerical methods and experimental verification. Authors of paper [7], in order to predict cavitation phenomena in the region of a clutch of the pump, built a 3D model for studying the dynamics of fluid motion. The analysis made it possible to detect the areas of cavitation, especially at a high speed of rotation of pump gears.…”