Modeling spiral drop structures in Extran

Does anyone have experience modeling spiral drop structures using Extran? I looked through the list archives and the last discussion on drop structures appeared in 1999. The general consensus at that time was that there might be ways to "trick" Extran, but another model might be more appropriate that considers air entrainment or using finite element analysis.

Has anyone had further experience with this in the past four years? Does anyone have specific experience with spiral drop structures?

Any help is appreciated.

Brad Roeth