The Erosion Technology And Experiment On Submerged Cavitating Jet

Cavitation jet technology combines water jet technology with the phenomenon of cavitation. It enhances the strength of the water jet with the use of powerful impact of bubbles collapse. It is widely used in situation of industrial cleaning、drilling、 material damage because of its power and efficience. It’s a promising hot area of academic research at home and abroad.This dissertation aims for the cavitation jet under the water. The study subjects lie how to produce high-strength Shear-type cavitation jet and different surface topography’s resistance to the cavitation jet erosion. We carry out systematic research of cavitation jet with the methods of standard specimen erosion、high speed camera、 noise measurement、and CLSM. The dissertation proposes the research scheme of visualization of cavitation jet, and we design the prototype. Furthermore, we carry many researchs to the cavitation jet nozzle, gaining the optimized model, which can be used in the situation of design. The erosion mechanism of different surface topography under the cavitation jet is also analysed.This dissertation consists the following seven chapters:Chapter 1 introduces the development and mechanism of underwater cavitation jet and the classification theory of cavitation jet, especially details the research progress and achievements of cavitation jet. This chapter also summarizes the advanced research methods about cavitation jet. A brief summary of the significances and contents of the dissertation research is described.Chapter 2 proposes the research scheme about visualization of cavitation jet. We design the experiment equipment and build it. Moreover, we analyse the cavitation jet picture and frequency spectrum with the use of high speed camera and hydrophone.Chapter 3 analyses the field of the cavitation jet in theory and by experiment. Also we quantitatively describe the numerical solution with the use of the CFD software.Chapter 4 mainly presents the strength of cavitation jet of the shear-type cavitation nozzle. We compare many different nozzle lips to find a better structure model by experiments.Chapter 5 presents surface topography’s corrosion resistance to the cavitation jet erosion macroscopically and microscopically using the Standard Test Method of erosion. Finally we revealed the law of surface corrosion subjected to cavitating jet.Chapter 6 shows the practical application we have carried out using cavitation water jet technology. we successfully cleaned the marine organisms attached to the ocean target with the use of our equipment.Chapter 7 summarizes the main research work and achievements of the dissertation. And the further research work and directions are put forward.