The Role of Viscous Fingering in the Separation Mechanics of Thin Interfacial Liquid Layers

This is a NAVAL POSTGRADUATE SCHOOL MONTEREY CA report procured by the Pentagon and made available for public release. It has been reproduced in the best form available to the Pentagon. It is not spiral-bound, but rather assembled with Velobinding in a soft, white linen cover. The Storming Media report number is A069773. The abstract provided by the Pentagon follows: The mechanics of separation of a thin interfacial liquid layer trapped between two parallel surfaces was studied in a controlled manner. Different liquid viscosities, layer thicknesses and separation velocities were used to investigate the extensional behavior and determine its dependence on viscous fingering, and Capillary number. Force, displacement and time data have been recorded for all experimental runs. Qualitative visual data have also been recorded to corroborate the trends in the onset of viscous fingering based on a simple interfacial stability analysis. The quantitative data has been used to generate force-displacement plots of the separation. The results of this work provide useful fundamental insight into the mechanics of this novel problem.