Abstract:In the present analysis, we studied numerically the effect of natural convection on deposition and dispersion of aerosols in a concentric horizontal annulus by means of control volume based finite element method. The governing equation is assumed for laminar, incompressible and 2D fluid flow while a Lagrangian description was used for simulation of spherical, solid particles immersed in the flow. The inner cylinder was under a constant heat flux and the outer one was maintained at a constant temperature (T c ). The Drag, Lift, Brownian and gravity forces were considered in the equation of particle motion. The results showed that Rayleigh number and increment of the aspect ratio change the rate of deposition as showed in the figures.