This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
This study addresses several issues in modeling of fluid flow phenomena in systems with deformable fluid interfaces and structured solid surfaces. The latter have been the subject of recent experimental studies motivated by potential applications ranging from microfluidic devices for chemical analysis to self-cleaning surfaces. However, the effect of size and shape of the small scale structures on the macroscopic fluid flow phenomena is still not completely understood and will be the focus of the planned studies. The problems of interest for the present study include impact of droplets on superhydrophobic surfaces, drainage of a film in contact with a structured surface, and the effect of surface structuring on the motion of liquid droplets on inclined substrates. To gain fundamental insights into these phenomena, mathematical models will be planned that take advantage of the small values of some parameters but do not rely on any ad hoc assumptions. New equations will be derived to describe the effect of dispersion forces and electrical charges at interfaces on the flow near structured solid boundaries. Theoretical results will be tested by comparison with both existing experimental data and the results of new experiments to be conducted as part of the planned studies. The planned project will promote learning through research and interdisciplinary scientific collaborations. Both graduate and undergraduate students will gain valuable research experience and expand their knowledge beyond their field of study by interacting not only with the PI but also with his collaborators working on experiments. As in the previous NSF-funded projects, the recruitment of minorities and women will be emphasized. The planned research also has broad technological impact. Potential applications of the planned work include the development of the so-called self-cleaning surfaces and advances in microfluidic technology.
