Large Eddy Simulation Of Turbulent Flow And Moving Behavior Of Particles

In this work, the theoretical study of turbulent field simulation of circumfluent cyclone separator (CFC) was carried out with FLUENT6.2 CFD software. The vortex in the separator, the moving behavior of the particles, as well as the factor which influence the separation efficiency of submicron particles were analyzed in order to improve the performance of the CFC.On tne base of Large-eddy simulation,the researcher put forward adding device of rectifier to improve the performance of the CFC .The works are as following:(1) The physical model of the laboratory experimental was established using GAMBIT, the preprocessor of Fluent. Through the reasonable distribution of the fluid field region in the CFC, excellent grids were generated which could satisfy the computation demands of Fluent.(2) Large-eddy simulation (LES) method of FLUENT6.2 was selected to simulate the inner piece, cirque and cone of CFC separator. By reasonable debugging, excellent convergent result and static pressure field and flow field was obtained.The static pressure in the inner piece and cone was compared to V. The static pressure reached to 950Pa in the wall of out piece. Tangential velocity at the bottom of cirque was 9m/s which was smaller than the Tangential velocity at the bottom of cirque(11lm/s).(3) Using the IFA-300, the flow field and the static pressure distribution had been measured in the CFC cone. The comparation of the experimental results and the simulating shows that large eddy simulation (LES) was successful.(4) On the basis of standard k-e model simulation, the moving behavior of micron particles was studied with the stochastic model of interaction with continuous phase elementarily, and the simulation results were compared with the experiments. It showed that the result of experiment can forecast the efficiency of different size of particles,but not enough good to the particles smaller than 6 μm.(5) The reason for the low efficiency of CFC when separating submicron particles was found by the simulation. The solution was put forward to add device of...