摘要

本文探討氣膠懸浮微粒在垂直平板上受熱泳效應及布朗擴散效應時，微粒附著率之影響差異。在這兩種效應的交互作用下，對微粒附著率有相當的重要性；採用垂直平板模型，統御方程式包括質量、動量與濃度方程式，在求解過程中，採用box-method與block-elimination解聯立方程式，進而算出粒子微粒附著的速度及參數。

所獲得計算結果，發現氣膠粒子在非均勻溫度場裡，其熱泳作用及對流效應對表面的沈積速率有很大影響。同時顯示被冷卻的垂直壁面，粒子有被吸附現象，而被加熱的垂直壁面，則有驅離情形。另一方面，當粒子直徑大於0.1 時，其沈積通量會趨近常數。另外，在助流的情形下，浮力對粒子沈積速率有成正比的關係。

Abstract
The heat transfer characteristic is combination of force convection and natural convection that flow over a vertical flat plat. The purpose is study of thermophoretic, Brownian diffusion and convection combined on aerosol particle deposition. The flow field was modeled as a two dimensional, incompressible and steady-state laminar flow. The governing equations include the conservation of momentum, mass and concentration. Non-similarity analysis with the box method and block elimination was to determine the velocity, temperature and concentration fields.
The effects of thermophoresis and convection were predicted to be important for submicron particles in the flow field. Thus, this theorem is worthy of note. The results showed the particle moving behavior that it is look like blowing away from a hot surface or suction from a cold surface at a temperature gradient field. Besides, the particle deposition rate increases with the particle flux will approach to constant, when the particle diameter greater than 0.1 . The influence of buoyancy on deposition, the deposition rate was proportional to the buoyancy in aiding flow.

1. J. G. Crump, and J. H Seinfeld., Turbulent Deposition and Grvitational Sedimentation of an Aerosol in a Vessel of Arbitrary Shape, J. Aerosol Sci., Vol. 12, no. 5, pp. 405, 1981
2. K. Okuyama, , Y. Kousaka, S. Yamamoto, and T. HosoKawa, Particle Loss of Aerosols with Particle Diameters between 6 and 2000 NM in Stirred Tank, J. Colloid and Interface Sci., Vol. 110, no. 1, pp. 214, 1986
3. G. K. Batchelor, and C. Shen, Thermophoretic Deposition of Particles
in Gas Flowing Over Cold Surfaces, J. Colloid Interface Sci., Vol. 107, no. 1, pp. 21, 1985
4. K. L. Walker, G. M. Homsy and F. T. Ghyling, Thermophoretic of Small Particles in Laminar Tube Flow, J. of Colloid and Int. Sci., Vol. 69, no. 1, pp. 138, 1979
5. W. W. Nazaroff, and G. R. Cass, J. Particle Deposition from a Natural Convection Flow onto a Verticle Isothermal Flat Plat, Aerosol Sci., Vol. 18, pp. 445, 1987
6. C. Shen, Thermophoretic Deposition of Particles onto Cold Surfaces of Bodies in Two-Dimensional and Axisymmetric Flow, J. Colloid and Interface Sci., Vol.27, no. 1, pp. 104, 1988
7. Y. P. Chang, R. Tsai and F. M. Sui, The Effect of Thermophoretic on Particle Deposition from a Mixed Convection Flow onto a Verticle Flat Plate, J. Aerosol Sci., Vol.30, no. 10, pp. 1363, 1999
8. H. T. Lin and L. K. Lin, Similarity Solutions for Laminar Forced Convection Heat Transfer from Wedges to Fluids of any Prandtl Number, Int. J. Heat Mass Transfer, vol. 30, no. 2, pp. 1111-1118, 1987

9. A. Bejan, Convection Heat Transfer, A Wiley-interscience Publishing, Canada, 1995

10. T. Cebeci and P. Brandshaw, Momentum Transfer in Boundary Layers, Hemisphere Publishing, Washington, 1977
11. T. Cebeci and P. Brandshaw, Physical and Computational Aspects of Convective Heat Transfer, Hemisphere Publishing, Washington, 1984
12. K. A. Hoffmann and S. T. Chiang, Computational Fluid Dynamics for Engineers. 1993

13. M. J. Huang and C. K. Chen, Conjugate Mixed Convection and Conduction Heat Transfer Along A Vertical Circular Pin, Int. J. Heat Mass Transfer, Vol.28, no.3, pp. 523, 1985

14. R. Tasi, Y. P. Chang and T. Y. Lin, Combined Effects of Thermophoresis and Electrophoresis on Partice Deposition onto a Wafer, J. Aerosol Sci. Vol. 29, no. 7, pp. 811-825 1998