A Legendre-spectral element method for flow and heat transfer about an accelerating droplet

The problem of flow and heat transfer associated with a spherical droplet a ccelerated from rest under gravitational force is studied using a Legendre- spectral element method in conjunction with a mixed time integration proced ure to advance the solution in time. An influence matrix technique that exp loits the superposition principle is adapted to resolve the lack of vortici ty boundary conditions and to decouple the equations from the interfacial c ouplings. The computed flow and temperature fields, the drag coefficient, t he Nusselt number, and the interfacial velocity and vorticity are presented for a drop moving vertically in a quiescent gas of infinite extent to illu strate the evolution of the flow and temperature fields. Comparison of the predicted drag coefficient and the Nusselt number against previous numerica l and experimental results indicate good agreement. Copyright (C) 2000 John Wiley & Sons, Ltd.