Effects of pulsating water jet impact on aluminium surface

It is well known that the collision of a high-velocity liquid mass with a solid generates short high-pressure transients which can cause serious damage to the surface and interior of the target material. To take advantage of this fact in the high-speed water jet technology, a special method of the generation of the high-speed pulsating water jet was developed recently and tested extensively under laboratory conditions. The method is based on the generation of acoustic waves by the action of the acoustic transducer on the pressure liquid and their transmission via pressure system to the nozzle. In this paper, results of investigation of the process of interaction of the pulsating jet and the aluminium sample are presented. Aluminium samples were exposed to pulsating jets generated under various operating conditions (such as operating pressure, stand-off distance and excitation amplitude of the acoustic generator). The effects of pulsating water jet impact on the aluminium surface were studied using methods of optical microscopy and image analysis. Topography of the surface created by the action of pulsating jet and characteristics of the surface were measured by the optical surface measuring system. Based on the analysis of obtained results, likely mechanism of the aluminium surface erosion and disintegration by the action of the pulsating water jet is discussed in the paper.