Multiphase flows with droplets involving gas (air), liquid (droplets) and solid (ice) phases are examined in this paper. The external multiphase flow is predicted in conjunction with a moving phase interface arising from solidification of impinging supercooled droplets. A scalar transport form of the droplet flow equations is solved separately from the viscous main (air) flow solver. This approach provides an effective alternative to tracking of individual droplet trajectories in the freestream. Interactions between the droplet and main (air) flows appear through appropriate inter-phase expressions in the momentum balance equations within each individual phase. The numerical formulation is based on a CVFEM (Control-Volume-based Finite Element Method) with quadrilateral isoparametric elements. This model is applied to problems involving the formation of rime (dry) ice (i.e., without liquid film covering the ice surface). Experimental data provides further insight into the impingement of droplets on a cylindrical conductor. Favorable agreement between the numerical and experimental results is achieved. (C) 2002 Elsevier Science Ltd. All rights reserved.