The Theoretical Analysis And The Study On Numerical Simulation Of Gas-Particle Two-Phase Spiral Flow Finishing Technique

The research is supported by the nation and Shanxi local science fund project, to research spiral flow finishing technique mostly. Gas-particle two-phase spiral flow finishing technique is to impel solid particles to swirl via spiral flow of gas, making solid particles to cut and rub the hole inner-surface by means of centrifugal force, then the quality of the hole inner-surface is improved. It is helpful to perfect the traditional and existing finishing technology ulteriorly.As the restriction of the equipment in common use, the study on performance of spiral flow finishing process only by experiment is not only long term, but also expensive. With the development of computer, numerical simulation plays increasing function. The numerical simulation has many merits ,for example, the devoted finance is less, the speed of design and computation is quick, the information is full and the ability of emulation and simulation is better. The numerical simulation is based on the theory of fluid dynamics and computational fluid dynamics. We set up a set of basic conserved equations in diversified complex conditions, make the assured conditions of the selected model, then solve direct these simultaneous non-linearity partial-differential equations, and accordingly get the distribution of every variables in the whole flow field. Therefore, studying on the law of fluid and the particle tracks in spiral flow of finishing process workpiece by numerical simulation, and then improving its configuration, and so have a important application worth in engineering.The thesis concentrate to the following contents: expatiate the basic knowledge of the two-phase; analyze the basic character of spiral flow, its characteristic to attenuate, the distribution of the static pressure in even diameter hole ; the friction force of particle in spiral flow; study the turbulent model and the method of numerical computation for spiral flow; do numerical simulation for the flow of gas, moving tracks of particles and vorticity magnitude,using Reynolds Stress Model based on anisotropy for gas flow field, and stochastic tracking model based on Lagrangian frame of reference for solid phase, which can reflect complex movement experience and collision of particle and wall via FLUENT. We have got the following conclusions from the simulation in the thesis:(1) In even diameter hole, the tangental velocity has the characteristic of combination vortex; with the boundary of points for maximal speed, the insides is norm forced vortex, the outside is norm free vortex; the axis symmetry of tangental velocity is very well. The pressure is the minimum in the center-axes, even the negative pressure. Along the axes, vorticity magnitude is much lower.(2) With the change of particle diameter, flux of gas, spiral angleαof nozzle, the tracks of particle alters. With the accretion of the particle diameter,the reduction of gas flux, the accretion ofα, the counters of spiral of particle tails off. Particle leaves off the tube earlier.(3) With the accretion of the counter of the particle and the gas flux, the force of the wall getted increase in even diameter hole.(4) Because the gas viscidity is smaller than the liquid viscidity and air is compressible, so in the same conditions, the tangental velocity and vorticity magnitude of gas is greater than liquid.The result of this simulation will accumulate some helpful materials for later experiment and equipment designed.