Numerical Simulation Of 3-D Turbulence Flow In Turbulence Mill

Ultra-fine comminution technology is a high-new subject involving many subjects and trades. It has made tremendous progress in all aspects because of appearance of new equipments and comminution processes from 70s in the former century. At the same time, it still has many phenomena which cann't be explained perfectly and technical problems which need better resolving methods. Our researching object he turbulence mill is such a new counter-rotating air mill. As tested bv experiments, as for comminution of macromeclule plastic material in normal temperature, turbulence mill has evidently advantages over other equipments, and a great future. To study intensively its comminuting mechanism, improving efficiency and configuration optimization, we must have a through understanding of its essential flow characteristics. Considering huge cost and long period by field measuring take numerical simulation method to analyze flow characteristics of the turbulence mill in the paper.The computional fluid dynamics (CFD) method was applied to simulate flow field of hydro-machines from 60s in the former century. The study on CFD has made tremendous progress because of development of computer capability and appearance of new numerical methods. At the same time, many general large softwares were developed based on that. The paper chose one of the most excellent softwares to simulating flow field of the turbulence mill.First, the paper give a simple introduction on the development of CFD and its application in simulating internal flow field of hydro-machines, then more detailed on its fundamental theories, practical process and various methods.Second, using Numeca, a 3-D viscous flow software, calculate internal flow field in the suck cavity, show flow characteristics in the suck cavity such as static pressure, relative velocity and eddies, and give advice for impeller optimization. Using FLUENT software, simulate whole flow field in turbulence mill, analyze calculated results in detail. Comparing with result obtained by Numeca, analyze their difference.Last, after analyzing carefully simulation results, consider shear stress arose from eccentric impact and friction play an important role in fatigue comminution in turbulence mill, then illustrate by facts. Based on it, bring forward a hypothesis that the mixture of air and particle can be regarded as a fluid for calculating shear stress. The experiment results prove the hypothesis. Finally conclude the corresponding experience, bring forward improvig measures and the next task.