Effect of thermophoresis on particle deposition rate from a mixed convection flow onto a vertical wavy flat plate

• Main Authors: Jheng-Jie Liang, 梁正傑
• Other Authors: Chao-Kuang Chen
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/17886086670880139266

碩士 === 國立成功大學 === 機械工程學系碩博士班 === 93 === 　In this study, Prandtl’s transposition theorem is used to stretch the ordinary coordinate system in certain direction. The irregular surface can be transferred into a calculable plane coordinate system. The governing equations of the system are derived from complete Navier-Stokes equations. The temperature gradient will influence aerosol particles which can cause the thermophoresis motion. The boundary layer equations deriving from non-similarity method can be solved by spline alternating-direction implicit method (SADI). There are more surface areas in wavy surface plates than flat plates so this study will figure out the deposition effect of aerosol particles causing by additional surface areas. 　There will be good agreements after simplifying the system and comparing with previous works. The numerical results show that the maximum deposition effect will happen near the peak within a complete wave. At this place, the deposition rate of wavy surface plates is better than flat plates. On the other side, the minimum deposition effect happens near the bottom of waves. There is better deposition rate in flat plates than wavy surface plates. The average deposition rate of wavy surface plates is much better than flat plates only in the first wave. It is almost equal or even worse than flat plates except the first wave. If there are stronger natural convection effect in mixed convections, there will be better chances cause that the average deposition rate of wavy surface plates is better than flat plates everywhere (except the beginning of plates). Otherwise, the outcome demonstrates the influence of smaller aerosol particles resulting from thermophoresis is smaller than bigger aerosol particles.