Numerical Simulation And Experimental Study On Jet Polishing Using Nanoparticles

Nanoparticles jet polishing is a new type of super smooth surface polishing method, it Can process arbitrarily curved surface and the surface roughness can be up to the atomic level without any damage. It is one of the most patient technology used in the current element on the surface ultra-smooth processing. In this paper, the numerical simulation models and grid partitioning method based on Gambit have been discussed. Furthermore, the parameters of numerical models are defined in CFD. A new hybrid multiphase flow model(Model C) is proposed based on the equivalent viscosity theory for the solid-liquid two-phase containing nanoparticles impinging jet flow, and it is compared with the DPM model considering the interaction(Model A) and the DPM model no considering the interactions(Model B). The applicable conditions of the three models are given according to the deviation comparing with the results of Model B. The orthogonal test was employed to optimize the structure parameters of nanoparticles jet polishing, including different nozzle exit diameters, shrinking angles, the ratio of length to diameter, and jetting height etc. The results indicate that the nozzle exit diameters have the most significant influence on material polishing removal efficiency. When the exit diameter equals to lmm, jetting height equals to 12d, the ratio of length to diameter equals to 4d, and the shrinking angle equals to 10 degree (d is the nozzle exit aperture), the effect of jet polishing is the best considering different kinds of particles, particles diameter, working pressure and injection Angle on the numerical simulation and experimental research. The results showed that with the number of increasing particle density and the working pressure, material removal depth is larger and linearly distributed. When the particle size is no bigger than 500nm, it can achieve the atomic level of removal, for the polishing depth of K9 glass; with the decrease of the jet Angle, oblique incidence of removal function become more complex, and the distribution of radial velocity curve of mining face is similar.