Previous and current experimental work has shown that miscibility disturbs the classical Hadamard-Rybczinski (HR) solution for the flow profile within a moving drop^1-2. The deviation from immiscibility leads to a ‘puddle' region on the back/bottom of the drop, and a front/upper region that appears to have quasi-HR flow. The ‘puddle' region appears to be formed by convective-diffusive flows, which lead to the formation of a mixing region (the ‘puddle'). We present herein an analysis that takes into account the partial miscibility of the drop with the ambient fluid, and qualitatively compare the predictions with experimental results.

1. M. Boland, E. Shafland, P. Arce, and D. Loper. Puddle Formation in Large Drops Moving at Low Reynolds Numbers in Highly Viscous Fluids: Preliminary Characterization of Motion. American Physical Society, Division of Fluid Dynamics Meeting, November 21-23, 1999, New Orleans.

2. E. Shafland, M. Boland, P. Arce, and D. Loper. Puddle Formation in Large Drops at Low Reynolds Number in High Viscous Fluids: Flow Visualization. American Physical Society, Division of Fluid Dynamics Meeting, November 21-23, 1999, New Orleans.