Drag Coefficient of a Spherical Particle Attached on the Flat Surface

The previous analytical solution for the drag coefficient (C(d)) for a spherical particle attached on the flat surface, which was derived by O'Neill (1968), is only valid in the creeping flow conditions. It is important to extend O'Neill's formula to cover a wide range of particle Reynolds number (Re(p)). In this study, the drag coefficient was calculated numerically to cover Re(p) from 0.1 to 250. For a particle suspended in the air, an empirical drag coefficient exists, which is defined as C(d) = f x 24/Re(p), where f is a correction factor depending on Re(p). The applicability of the correction factor f for O'Neill's analytical equation for the spherical particle attached on the flat surface for Re(p) = 0.1 to 250 was examined in this study.