Contact: Oleg Urazmetov

Technical surfaces can be processed with high-pressure water jets. For example, a metallic surface can be pre-treated with high-pressure water jets for a coating process step. This creates a rough surface, the properties of which can be varied by different parameters. Parameters such as droplet size and velocity play a role, while other parameters include the duration and frequency of impact. The mechanism responsible for material removal is called droplet erosion. The water jet breaks into fine droplets due to aerodynamic forces, which is also called atomization. The droplets strike the surface and create pressure waves in the material, resulting in cracking.
For machining with high-pressure water jets, a focused jet is often desired, which travels in controlled paths over the surface. The flow within the nozzle has a decisive influence on the stability of a waterjet. Strong turbulence or swirling enhances the atomization process. The flow inside the nozzle can only be determined by measurement with very high effort. For this purpose, numerical flow simulation offers an effective tool to determine the flow conditions inside the nozzle.