Aerosol Science 36 (2005) 495 – 520 www.elsevier.com/locate/jaerosci Deposition of fine aerosols in laminar tube flow at high temperature with large gas-to-wall temperature gradients R. Muñoz-Bueno a , ∗ , E. Hontañón a , M.I. Rucandio b a Dpto. de Combustibles Fósiles, CIEMATAvenida Complutense 22, 28040 Madrid, Spain b Laboratorio de Química Analítica, CIEMAT Avenida Complutense 22, 28040 Madrid, Spain Received 21 May 2004; received in revised form 3 November 2004; accepted 3 November 2004 Abstract This work provides experimental data on thermophoretic deposition of submicron aerosols (2 <Kn< 30) in laminar tube flow at temperatures of 400.600 ◦ C and gas-to-wall temperature differences of 300.400 ◦ C. This range is significantly higher than in previous experiments and of technical interest. Fluid flow in a cylindrical tube as well as aerosol transport and deposition in the thermal gradient were simulated using a CFD computer code (Fluent) and the Talbot expression for the thermophoretic velocity, with the thermophoretic coefficient  t as a fit parameter. It was found that a constant value of  t = 0.55 was an acceptable choice for engineering applications, to accurately estimate thermophoretic deposition efficiencies and deposition rates in the range of particle sizes (20–200 nm) and gas temperatures (130.580 ◦ C) which were covered in the experiments.  2004 Elsevier Ltd. All rights reserved. Keywords: Thermophoresis; High temperature gradient; Fine aerosols; Talbot’s formula; CFD simulation 1. Introduction The topic under study here is the thermophoretic deposition behaviour of submicron aerosols in gases at high temperature with large temperature differences between the gas and the deposition surface. On this regard, this work is aimed at validating the classical theories of thermophoresis in the transition and free- molecule regime for the purpose of predicting aerosol deposition in hot particle-laden gases. This issue is of great interest in many industrial and technological applications. In the production of fine and ultrafine ∗ Corresponding author. Tel.: +34 91346 6131; fax: +34 91346 6269. E-mail address: rafa.bueno@ciemat.es (R. Muñoz-Bueno). 0021-8502/$ - see front matter  2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.jaerosci.2004.11.002