Systematic experimental and numerical studies have been fulfilled at GRETh. The numerical simulation uses a classical Eulerian-Lagrangian approach. It relies on the precise description of the temperature and velocity fields obtained by using the TRIO software without any turbulence model. As all these results are in good agreement with literature, particles tracking allows the determination of the mass transfer coefficient by counting the number of particles reaching the cylinder surface per unit time. Experimentally, in order to cover the whole size range, two particle generators have been used. Both experimental and numerical results are close together. Moreover the role of the particle inertia before the onset of the inertial impaction is clearly established along with its competition with the thermophoretic effect.