Thermophoretic and photophoretic motions of aerosol spheroids

碩士 === 國立臺灣大學 === 化學工程學研究所 === 92 === An analytical study is presented for the thermophoretic and photophoretic motions of a freely suspended aerosol spheroid in a uniform prescribed temperature gradient or radiative heat flux that is oriented arbitrarily with respect to its axis of revolution. The...

Full description

Bibliographic Details
Main Authors: Chang-Lin Ou, 歐昌霖
Other Authors: Huan Jang Keh
Format: Others
Language:zh-TW
Published: 2004
Online Access:http://ndltd.ncl.edu.tw/handle/30067410223777586469
Description
Summary:碩士 === 國立臺灣大學 === 化學工程學研究所 === 92 === An analytical study is presented for the thermophoretic and photophoretic motions of a freely suspended aerosol spheroid in a uniform prescribed temperature gradient or radiative heat flux that is oriented arbitrarily with respect to its axis of revolution. The Knudsen number is assumed to be small so that the fluid flow is described by a continuum model with a thermal slip at the particle surface. In the limit of small Peclet and Reynolds numbers, the appropriate energy and momentum equations are solved in the quasisteady situation using the bifocal-coordinate transformations. Explicit expressions for the thermophoretic and photophoretic velocities and forces are obtained for various cases of prolate and oblate spheroidal particles. The average thermophoretic and photophoretic velocities and forces for an ensemble of identical, non-interacting spheroids with random orientation distribution are also determined. The results indicate that the shape and relative thermal conductivity of a spheroidal particle and its orientation with the thermal gradient or the incident light can have significant effects on its thermophoretic or photophoretic behavior.