Validation of a model for cavitation-induced wall erosion in a piston oil pump

Cavitation is a main concern in hydraulic pumps, since it’s associated with decreased performance and components erosion, which could eventually lead to the complete failure of the machine. Many commercial computational fluid dynamics (CFD) solvers can model and predict cavitation phenomena in hydraulic pumps, and some also allow to obtain an estimate of the associated wall damage. What such models are lacking tough is the possibility to automatically modify the geometry of the fluid domain to mimic the progressive material removal on the walls. This feature could improve the prediction of the pump behaviour after the first occurrence of wall erosion, as well as forecast the useful life of the components and help in making design modification to extend it. The goal of the this work is to validate a new simulation model which provides the capability to simulate the evolution of the erosion in time. This tool has been developed by the CFD software provider Simerics,. The validation of this model is conducted on the port plates of two different oil piston pumps which both showed strong erosion during testing. The pumps are produced by the company Casappa Spa, which also provided the experimental data necessary for the calibration and validation of the model. The validation was done through a multistep CFD simulation method which tried to reproduce the same results seen on the testing samples. None of the simulations performed within the timeframe of this work was able to satisfyingly reproduce the experimental results, but it was possible to gain an accurate insight into the physics of the problem and into the improvements necessary to the model in order to obtain an accurate prediction.