In this paper, a two-way couple of Eulerian-Lagrangian model is used to simulate and account the discrete nature of Al2O3 particles in a particulate channel flow with a built-in heated obstruction. The governing equations for fluid flow and particle motions are solved by using the finite volume and trajectory analysis approaches. The simulations are performed for different particle sizes and solid volume fractions of particles (φ) in the ranges of 30–500 nm and 0–0.05, respectively and at fixed values of blockage ratio (S = 1/8) and Reynolds number (Re=100). The effects of interaction forces acting between the fluid and particles containing the drag, gravity, Brownian, and thermophoresis forces on the particle transport and thermal behaviour of systemare investigated. It was found that the nanometer particle does not follow the flow streamline and in fact diffuses across the streamlines. For larger sizes (i.e. 100 and 250 nm), particles concentrate in the vorticity regions around the periphery of the vortices. Moreover, the particle deposition percentage increaseswith an increase in the particle size.

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