The Numerical Simulation of Particle Motion on the Electric Field Using Computational Fluid Dynamic

• Main Authors: Jin-Yuan SYU, 許晉源
• Other Authors: Wen-Yinn LIN
• Format: Others
• Language: en_US
• Online Access: http://ndltd.ncl.edu.tw/handle/ubga6t

博士 === 國立臺北科技大學 === 工程科技研究所 === 105 === Particle migration is a popular topic in physical science, environmental science and atmospheric science, especially in the particulate matter treatment design. In additional, computational fluid dynamic (CFD) is the applicable pre-tool for particle trajectory simulation. The objective of this study tries to simulate the ion concentration and distribution in ESP, and goes to calculate and analyze the behavior of particle charge and migration. Thus, this thesis presents a hybrid numerical method of particle motion on the electric field by using a hybrid numerical technique based on CFD. In particle motion calculation, this method tried to balance the effect of electrostatic force, gravitation, and drag force within different particle size in a single wire-plane electrostatic precipitator (ESP). Hence, a wire-plate ESP was set up, and the three dimension characteristics of the fluid flow and electric field were all simulated by ANSYS CFX software. Moreover, the study attempts to use the grid separation to differentiate the particle charge in each time step. The results indicated that the number of elementary charge in particle was related with time steps. As the charge time increased, the number of elementary charge in particle was increased. Besides, the inlet position will affect the particle migration due to different ion distribution and electric field intensity. The coarse particle was quickly to achieve the terminal velocity (20~80 μm), however, the fine particle should have more residence time to receive enough charges. As particle crosses near the corona zone, it must get more elementary charge, and must receive stronger electric field, thus, the particle charge and migration will be better. Consequently, stronger electric field, more ionic flux and longer residence time will increase the particle charge and improve the electrical mobility.