Thermophoretic Deposition of Particles in Laminar and Turbulent Tube Flows
Authors: Chuen-Jinn Tsai1; Jyh-Shyan Lin1; Shankar Aggarwal1; Da-Ren Chen2
Source: Aerosol Science and Technology, Volume 38, Number 2, February 2004 , pp. 131-139(9)
Publisher: Taylor and Francis Ltd
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Abstract:
Thermophoretic deposition of aerosol particles (particle diameter ranges from 0.038 to 0.498
m) was measured in a tube (1.18 m long, 0.43 cm inner diameter, stainless steel tube) using monodisperse NaCl test particles under laminar and turbulent flow conditions. In the previous study by Romay et al., theoretical thermophoretic deposition efficiencies in turbulent flow regime do not agree well with the experimental data. In this study, particle deposition efficiencies due to other deposition mechanisms such as electrostatic deposition for particles in Boltzmann charge equilibrium and laminar and turbulent diffusions were carefully assessed so that the deposition due to thermophoresis alone could be measured accurately. As a result, the semiempirical equation developed by Lin and Tsai in laminar flow regime and the theoretical equation of Romay et al. in turbulent flow regime are found to fit the experimental data of thermophoretic deposition efficiency very well with the differences of less than 1.0% in both flow regimes. It is also found that Talbot's formula for the thermophoretic coefficient is accurate while Waldmann's free molecular formula is only applicable when Kn is greater than about 3.0.
Document Type: Research article
DOI: 10.1080/02786820490251358
Affiliations: 1: Institute of Environmental Engineering, National Chiao Tung University, Hsin Chu, Taiwan 2: Department of Mechanical Engineering, Joint Program in Environmental Engineering, University of Washington in St. Louis, St. Louis, Missouri, USA
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