Abstract
We investigate the density field of particle phase in low Stokes number region of 2-fluid Saffman equation which is a model of dilute particle flow on 2-fluid description with incompressible carrier flow. In the stagnation region of inviscid carrier phase, we find an exact solution of particle flow field and some features of the velocity and density fields are clarified. Furthermore, we reconsider Michael's criteria on the appearance of particle free layer. The order estimation of particle velocity field leads to the new criteria δ<κτ (δ,κ and τindicate the thickness of viscous boundary layer, the curvature and Stokes number) and computational results support the present criteria.
