Development of a hydroerosion model using a semi-empirical method coupled with an Euler-Euler approach

The aim of the present study was to develop a numerical model that predicts the quantity and location of erosion damage in hydraulic systems susceptible to erosive wear. This model has been integrated into the commercial CFD code ANSYS-CFX, which solves the full Navier-Stokes equations for the turbulent flow field and takes into account the change in geometry by utilising a ‘mesh morphing’ feature. Particles sizes within the sub-micron range and mass loadings of up to 2% were investigated. <br><br>Unlike the classical Lagrangian approach of solving the particle equations of motion, both phases were solved using an Eulerian approach whereby a statistical model was necessary to define the particle impact-angle, velocity and mass. An Eulerian approach was favoured in this case not only due to reduced computational time, but also due to the ease of modelling the abrasion mechanism which was found to be the dominant component of wear in the present application. <br><br>A slurry jet erosion apparatus was developed in order to evaluate experimentally the parameters influencing the erosion process. The apparatus was based on a closed-loop slurry circuit which was pumped through a converging-diverging throttle before coming into contact with an inclined surface. Four different angles of inclination were investigated ranging between 45 and 90 degrees at intervals of 15 degrees. In addition to this, the effect of test parameters such as slurry velocity, viscosity, particle size and concentration were studied. <br><br>All experimental tests were conducted using simplified planar geometries constructed from a chromium-nickel based corrosion-resistant stainless steel typically found in household appliances. The geometries were subject to typical hydro-erosive conditions, such as that used for the deburring of diesel injector spray-holes. The results were used to calibrate the developed erosion model which showed promising trends in comparison with experimental studies for predicting the location and quantity of erosive wear.<br>