Tri-thermal device sizing for thermophoresis deposition measurements of nanoparticle soot aggregates

Abstract

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.

Thermophoresis is the motion of particles from the hot to the cold region of a gas subjected to a thermal gradient. This phenomenon contributes to the fouling of EGR (Exhaust Gas Recycling) systems in automotive applications. The aim of this work is to develop a tri thermal device to study the collect of soot particles by thermophoresis. In this device soot particles flow in the annular space between two concentric tubes with imposed temperatures. We will use the so called penetration method which is based on the measurement of particle deposition in the test section. The precision of this method is often limited by the low deposition rates; the main objective of this study is then to size an efficient and compact device for thermophoretic deposition, while respecting mechanical and thermal constraints. We used CFD (Computational Fluid Dynamic) numerical simulations and model results to choose an optimal design of the device, which is composed of hot and cold tubes with diameter respectively equal to 87 and 85mm and with 0.5 meter long tubes.