The inertial lift on a spherical particle in a plane Poiseuille flow at large channel Reynolds number

The inertial migration of a small rigid sphere translating parallel to the walls within a channel flow at large channel Reynolds numbers is investigat ed. The method of matched asymptotic expansions is used to solve the equati ons governing the disturbance flow past a particle at small particle Reynol ds number and to evaluate the lift. Both neutrally and non-neutrally buoyan t particles are considered. The wall-induced inertia is significant in the thin layers near the walls where the lift is close to that calculated for l inear shear flow, bounded by a single wall. In the major portion of the flo w, excluding near-wall layers, the wall effect can be neglected, and the ou ter how past a sphere can be treated as unbounded parabolic shear flow. The effect of the curvature of the unperturbed velocity profile is significant , and the lift differs from the values corresponding to a linear shear flow even at large Reynolds numbers.