Correlation for thermophoretic deposition of aerosol particles onto cold plates

Abstract

A rational correlation for evaluating the effect of thermophoresis on aerosol particle deposition from laminar flow systems was developed. The flows considered were flat-plate flow and stagnation in plane and axisymmetric flows with variable properties for cooled plate surfaces. This procedure is based on the concept of high-mass transfer with a thermophoretic factor. This factor is treated with a product of two functions that are a suction-like convection term and a sink-like term. The particle flux to the plate surface, expressed in terms of the particle Stanton number, was obtained from the product of the particle Stanton number in the limiting case ( V T→0) and the thermophoretic factor. The results were correlated from the numerical solutions for self-similar boundary flows and provided a maximum possible error less than 3% over the range of 0.3⩽ κ⩽1.0 and 0.2⩽ T w / T ∞⩽1.0. To examine the effect of flow properties for stagnation flow upon the deposition rates between the variable and constant flow properties, the error increases with an increase in the temperature difference between the plate and free stream and becomes about 50% as T w / T ∞=0.2.