Surface Evolver – Fluid Interface Tool (SE-FIT®) software is a Windows application that consists of a graphical user interface front end with the Surface Evolver (SE) serving as the computational engine. SE is a unique and powerful tool for computing the shape and stability of equilibrium fluid interfaces. SE-FIT® is developed to improve accessibility to command line based SE and to expand the overall capability of SE so that important fluid interface information can be computed in a timelier, more routine, and more frequent manner. Improvement in design efficiency is at least an order of magnitude greater than when using existing Computational Fluid Dynamics programs. The SE-FIT® program is currently developed by the Capillary Fluidics Lab at Portland State University.

SE is an ideal tool for studying fluid interfaces in different settings, including but not limited to microgravity tankage and propellant management device (PMD), inkjet printing, nanotechnology, porous media, self-assembly, foam, and micro-scale wicking structures, to name a few. In general, for such applications body forces are often negligible compared to surface forces resulting in a small Bond number, a dimensionless parameter the ratio of body forces to surface forces. SE-FIT® offers a suite of prebuilt geometries that can be customized for further computation. As one of the major features, a Parameter Sweep Function is developed to either compute equilibrium surfaces or identify surface stability limits in batch mode, which significantly reduces computation time. The overall capabilities of SE-FIT® are well-suited for the purposes of education and research as well as engineering design.