Study On Numerical Simulation On Flow Field In Cavitating Cleaning Nozzle

Cavitation jet have high efficiency, water-saving, time-saving, low cost, pollution-free advantages. Used for coal mining, oil drilling, etc, and the hull, pipeline cleaning has got preliminary application. Based on the design of cavitation nozzle optimal structure parameters as the goal, used empty bubble dynamics, cavitation and turbulence theory, this paper analyses the characteristics of cavitation jet cleaning, cavitation jet formation mechanism, cavitation effect theory and dynamic characteristics. Theoretical analysis cavitation nozzle working principle, structural characteristics, producing strong cavitation jet flow field of characteristics, jet flow characteristics, and so on.For researching on the influence of a nozzle geometric parameters on the property of efflux flow field, this paper use the basic knowledge of Computational Fluid Dynamics to give the pre-processing according to the order, the modeling,meshing, boundary and initial conditions and the solution control setting were detailed illustrated. And by using FLUENT software of turbulence model for jet flow rate, pressure, physical properties conducted the three-dimensional flow of numerical simulation. Under the same boundary conditions and initial conditions, changed respectively angle nozzle and shrinkable tubing nozzle the size of the diffusion angle, the length of diffusion segment and cylindrical section length, with FLUENT software for two kinds of nozzle speed and pressure attenuation characteristics simulated and analyzed respectively, obtained two nozzles to the optimal structure parameters.Eventually, by using FLUENT software, flow model is established on the basis of navier-stokes equations, choose the mixture model combining based on density of cavitation model and RNGκ?εturbulence model, angle nozzle and shrinkable tubing nozzle of two-dimensional numerical simulation of jet flow field is conducted. The article analyzes two cavitation nozzle internal and external pressure field, velocity field and containing gas rate regularity of distribution, and with pressure, velocity and containing gas rate as evaluation parameters of optimized cavitation nozzle structure of the comprehensive analysis and comparison, cleaning and cavitation effect of two cavitation nozzle is verified, to provide theoretical reference for the practical application.