The interaction of a solidification front with an embedded particle is studied using numerical simulations to couple phase change with particle motion. The particle moves under the influence of forces that act across the gap between it and the advancing solidification front. Among these forces is a drag force that pushes the particle towards the front. Different drag expressions have been used in the past for a spherical particle interacting with an advancing solidification front. The coupled front-particle interactions using two drag expressions are compared. It is shown that the predictions of the critical velocity are influenced by the drag law used. It is also shown that the treatment of the front-particle interaction calculations as fully coupled or otherwise impacts on the predictions of the critical velocity for engulfment. Results from the present fully coupled numerical model are compared with a semi-analytical approach to demonstrate the differences in the predicted critical velocity. (C) 2003 Elsevier Science B.V. All rights reserved.