A Study of Microgravity on Fluid Instabilities in Microfluidic domain

Computational fluid dynamics (CFD) analysis is applied to increase the understanding of gravity on fluid instability phenomenon. The effort specifically studies viscous fingering patterns in a microfluidic device. In addition, the effort aims to support microgravity experiments that will utilize imagery using a lens free imaging (LFI) system to capture the data. The purpose of the study is to provide preliminary data using CFD analysis software STAR-CCM+ to predict how a suborbital flight experiment using microfluidic flow will transpire. Lab experiments were conducted to observe Saffman-Taylor or viscous fingering instability in microfluidic devices using liquids that include water, ethanol, and corn syrup. A study was done to quantify the viscous finger length and width with respect to the microfluidic device chamber size. The results show a correlation between viscous finger patterns and the device geometry.  A second study was done to analyze the effects of gravity and microgravity on the viscous fingering phenomenon. Microgravity is simulated using CFD to refine the experiments a priori the suborbital flight later. This study shows the effects of the force of gravity may have on viscous finger patterns. The comparison of the data captured in the lab and suborbital flight experiment to the CFD results provide further insight into the accuracy of the CFD modeling with respect to microfluidics behavior in microgravity.