Numerical Analysis of Aerosol Trap Impactor

• Main Authors: Wen-Hung Wang, 王文宏
• Other Authors: Yu-Chen Chang
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/47938796825258028716

碩士 === 元智大學 === 化學工程學系 === 90 === Simulation of aerosol dynamics in a trap impactor previously reported by Biswas and Flagan(1988) using the computational fluid dynamics (CFD) package FLUENT is reported here. A 3-D model of the trap impactor is created using mesh creation software BITMAP and FLUENT for setting up fluid and particle dynamics in the physical system. The orifice-to-jet ratio and cavity-depth to orifice diameter used in all simulations presented here are 1.9 and 3.0, respectively. Results presented here include the gas pathline or streamlines and gas Reynolds number in the trap impactor, as well as a comparison of particle collection efficiency versus the square root of Stokes number between simulation and experiments by Biswas and Flagan (1988). Assume the impactor is operated at steady state and turbulent k-εmodel applies. The maximum calculated Mach number in the impactor was 0.5, less than unity. The results presented here are the effect of mesh size on flow properties and their comparison to Marple's(1970) results. The final choice of the mesh size scheme was chosen optimized in terms of computer time and accuracy. Further efforts are still needed to improve the model to a more sophisticated one. Different k andεvalues were used in simulation and their effect on deposition efficiencies of different particle sizes were investigated.