2011-01-26
10:15 at HCI J 574

Two Interesting Problems in Fluid Mechanics

David C. Venerus

Chemical Engineering, Illinois Institute of Technology

In this seminar, two problems in fluid mechanics are investigated. The commonality between the two problems lies in the fact that they are both interesting and accessible to the presenter, who is an experimentalist. The first problem concerns the effects of transducer compliance on transient stress measurements in torsional flows of a viscoelastic fluid, which play an important role in the experimental rheology of complex fluids. The second problem is laminar flow of compressible Newtonian fluids in capillaries and channels, which is relevant to flows in microfluidic devices. Both problems are solved using a simple perturbation method. In the torsional flow problem, we find a new criteria for avoiding transducer compliance, and a possible connection to instabilities in rheometric flows that have been a subject of great interest in recent years. For the compressible flow problem, we find that a commonly used method for analyzing microchannel flow experiments obscures a rather simple dependence of pressure drop on the same parameter used in the perturbation method.