Numerical Simulation of Water Jet Quality for Different Orifice Geometries

Abstract

1. Introduction Manufacturing requirements are increasing in terms of precision and productivity, for which novel processes are needed. Plain water jet cutting process (PWJ) is one of the most versatile [...] In plain water jet machining process (PWJ) an initial collision occurs between the jet and the wall of the orifice during the jet formation through a standard orifice, which disturbs the flow. The internal geometry has an important influence in the quality of the jet, and therefore in the cutting quality. This work presents a computational fluid dynamic (CFD) analysis with the aim of studying the effect of the internal geometry of the orifice on water jet characteristics. Different models were simulated modifying the upper part of a standard orifice. The results showed that the initial collision can be avoided and thus, disturbances on the external surface of the jet can be decreased modifying the internal orifice geometry, which leads to more stable cutting conditions. This analysis can serve in the future to optimize the internal geometry of the orifice and thus, to improve the characteristics of the water jet for each specific application, e.g., texturing or cutting.