Experimental study on the influence of geometrical parameters on the cavitation erosion characteristics of high speed submerged jets

The influence of the geometrical working parameters on the cavitation erosion process was experimentally investigated by exposing the surfaces of copper samples (as a kind of Face Centred Cubic material (FCC)) to a high speed submerged cavitating jet for various time periods using a cavitating jet generator. The resulting erosion rate and eroded area is discussed in detail. Influences of the non-dimensional standoff distance, the non-dimensional aspect ratio and the angle of attack is experimentally determined. The results show that the erosion rate and weight loss are strongly depending on these separately investigated parameters. With this test rig facility and applied hydrodynamic parameters the maximum erosion was found to take place with a non-dimensional standoff distance varying between 42 and 48 (depending on the nozzle diameter), with a non-dimensional aspect ratio of 11 and with 105° angle of attack. A model to explain the influence of the angle of attack on the erosion rate based on the cavity bubble and target surface interaction is presented. In addition, the obtained results demonstrate that the used small-diameter (0.4-0.6 mm) water cutting nozzles could be applied for metal machining by cavitation and cavitation cutting with low power consumption and high cutting efficiency.