Research On High Pressure Waterjet In Remanufacture Cleaning

Serious environmental pollution, resource consumption, is a major problem restricting China’s21st century sustainable development, since China has entered a peak period of scrapped machinery, equipment and household appliances, If all are melted, it will inevitably cause a huge waste of resources, as a result, remanufacturing emerged. Because of enormous resources and environmental benefits of remanufacturing, it is necessary to carry out the remanufacturing research, remanufacturing cleaning is an important process in the parts remanufacturing process, the premise of detection and repair of remanufactured components, and the foundation of part remanufacturing.The high-pressure waterjet as an emerging technology, which is developing very rapidly in recent years, is able to complete the cleaning, cutting, crushing and other processes. The high-pressure waterjet cleaning is a physical cleaning method, Due to low cleaning cost, fast cleaning rate, without damaging cleaning materials, a wide range of applications, without polluting the environment and many other advantages, the application of high-pressure waterjet in remanufacturing cleaning has great practical significance.In the present research, Computed Fluid Dynamics is conducted to investigate the influence of nozzle geometric parameters on flow field inside and outside the nozzle, and the distribution of jet impact dynamic pressure in the high pressure waterjet cleaning.①the influence of nozzle geometric parameters on the flow field inside the nozzle are investigated, mainly for the nozzle cone angle, aspect ratio, the nozzle inlet diameter and outlet diameter, the cavitation model and two-phase flow model are used to analyze the influence of the nozzle structure on the cavitation degree inside the nozzle.②gas-liquid two-phase flow distribution outside the nozzle are investigated, Eulerian mass flow model is cited, coupled to the continuity equation in FLUENT software by user-defined functions, the validity of the model is verified by related scholars’ research, the distribution of the free flow field outside the nozzle, the jet impact dynamic pressure distribution are also investigated, the size of dynamic impact pressure on the cleaning research is of great significance.③Single factor experiments were conducted to investigate the jet impact force variation on different pressures and different stand-off distance, and compared with the simulation results is to further verify the validity of the above model. The principle of selection of high-pressure water jet cleaning parameters is analyzed, Combined with simulation results and related theories, the optimal stand-off distance can be got, the influence of impact angle on the jet flow field is also, analyzed, the principle of selection of the angle of incidence is put forward.In this research, the distribution on flow field inside and outside waterjet nozzle is investigated, especially the influence of nozzle geometric parameters on flow field inside the nozzle and the distribution of jet impact dynamic pressure, the optimal stand-off distance can be got, the size of impact dynamic pressure and the impact width are extremely important role on the nozzle arrangement and the cleaning efficiency, these can provide theoretical guidance and technical support for studying specific dirt cleaning and process parameters.