CAREER: Microflow of Highly Viscous Fluids: Mixing and Dissolution Processes

1150389 Cubaud High-viscosity fluids represent a broad class of materials that are essential to many aspects of energy technologies and life. We know from everyday observation that viscous fluids are sticky and thick. They tend to attach to surfaces and they form filamentous structures when manipulated. Their large viscosity coefficient makes them slow and difficult to displace, and blending them with other materials requires a long time. Today, the limited supplies of fossil energy resources require the development of innovative methods for finely handling viscous materials and gaseous byproducts over multiple length scales. This project combines educational and research activities designed to expand the scientific foundations for new and improved manipulations of highly viscous fluids at the small scale. Novel strategies will be deployed to rapidly mix and enrich thick materials using high-pressure microfluidic devices. Two research thrusts are proposed. The first involves blending low- and high-viscosity miscible fluids in continuous flow configurations. The formation of viscous stratifications and the stability of lubricated threads against diffusion, inertia, and viscous buckling phenomena will be experimentally and numerically modeled in confined microgeometries. The second investigation focuses on microscale dissolution processes of carbon dioxide with viscous fluids. Segmented microflows of dissolving gas bubbles will be examined for impregnating viscous substances and unlocking the fundamentals of carbon sequestration in porous-like media. This work will lead to the development of predictive models and improve our understanding and practical use of liquid/liquid and liquid/gas multiphase flows in the presence of diffusive interfaces at the small scale. Intellectual merit: This project will provide a comprehensive and unifying picture of the flow behavior of viscous fluids with miscible lubricants. A series of carefully designed experiments, theoretical arguments, and numerical modeling will generate a reliable and systematic knowledge concerning the emerging properties of high-viscosity microflows and viscous buckling instabilities. Carbonated multiphase flows will be characterized at the pore level over a wide range of fluid properties and operating parameters. This work will expand the frontier of understanding in fluid dynamics and open up a new era of fluid processing capabilities. Broader impacts: This program will offer substantial educational opportunities for a diversity of students, including underrepresented, high school, undergraduate, and graduate students. The PI will dedicate his efforts to educate and train students to cutting edge research in fluid science. Results developed during this project will be incorporated into the PI's outreach and teaching activities at every level. This work will help improve continuous flow-based mixing apparatuses for high-viscosity fluids and offer new expertise for the microflow management of petrochemical products and viscous biomaterials, the recycling of used oils, and the capture of carbon-based byproducts.