Research On Experiments And Numerical Simulation Of The Flow Field For Colloid Hydrodynamic Cavitation Jet Polishing

With the high speed developing in the present optics, film and integrated circuit (IC) field, the optical elements and electrical devices have higher and higher demand of the surface quality such as super-smooth surface. The traditional mechanical lapping and polishing leave subsurface damage unavoidably. So, researchers around the world are devoted themselves on the seeking and developing processing methods in new principle. On this paper the nanoparticle colloid hydrodynamic cavitation jet polishing was exploring one kind of green super-smooth surface processing method with high efficiency based on the comprehensive profound research on the nanoparticle colloid jet machining.Firstly, research on the theories of the ordinary jet, the swirling jet and the cavitation jet. Analysis the structural characteristics of the submerged jet and non-submerged jet, the ordinary cylindrical jet and the swirling jet, as well. Then cavitation jet generating conductions and cavitation jet function theory were studied. The Finite Volume Method analysis models were established for the submerged and non-submerged jet flow, which proposed the theoretical basis for the later flow field simulation and experiment exploration.Secondary, the nanoparticle colloid jet flow fields were simulated and analyzed. The submerged impact jet flow fields were analyzed of both the corn-shape jet nozzle and the swirling jet nozzle, the velocity and pressure distribution of the whole flow field, the velocity and pressure distribution on the workpiece surface, the flow turbulence intensity and the cavitating zone distribution were especially considered. The non-submerged impact jet flow field was simulated to compare the different characteristics of the non-submerged and submerged jet.Finally, the nanoparticle colloid hydrodynamic cavitation jet polishing experiment platform was put up and the K9 optically flat glass exploratory experiment was carried out. The jet patterns and polishing effect were compared belong different nozzles to seek for more suitable one. The scratch on the workpiece was removed obviously after polishing, but some white crowning and pits were detected. Through polishing using nanoparticle colloid in bigger size and water, the white crowning was reduced and the pits were suspected caused by the cavitating disruption in high pressure. No pits were detected using water jet in low pressure, which showed that cavitation had no disruption in low pressure. Better surface was obtained when the nanoparticle colloid was used in low pressure, which demonstrated the feasibility for the nanoparticle colloid hydrodynamic cavitation jet polishing to be used in getting high-quality surface.