Center for Fluids at all Scales
What is CFAS?
The purpose of CFAS is to promote research and disseminate knowledge on the study of fluids at all physical scales, from the microscopic to the macroscopic. The Center also aims at promoting research on the application of fluid knowledge to various areas of the sciences and engineering. Examples of current research include studies of the micron-sized channels in microfluidic devices and blood vessels, the turbulence found behind parachutes and aircraft (see photo, courtesy of US Army Natick Soldier Center), and the superfluid interiors of neutron stars. CFAS is inherently a multidisciplinary enterprise that regroups researchers and students from Saint Louis University and elsewhere. CFAS sponsors monthly seminars on the activities of its members, as well as on research presented by visitors and guests. CFAS also aims at promoting joint research projects regrouping experts of various disciplines and academic departments. Visit News and Publications pages for additional information.
- Microfluidics: applications to biomedical lab-on-a-chip devices and biofuelcells
- Biofluids: red blood cell rheology (Dr. Minteer)
- Theory and modeling of turbulence: incorporating effects of transition, flow unsteadiness, and compressibility (supersonic flows) (Dr. Thacker)
- Computational fluid dynamics: aerothermodynamics, astrophysical simulations (Dr. Comer)
- Fundamental principles governing fluids at all scales: multi-fluid formalism that includes dissipation (Dr. Comer and Dr. Thacker)
- Astrophysical fluid dynamics: oscillations in superfluid neutron stars and their associated gravitational wave emission (Dr. Comer)
G. Comer, Ph.D.
S. Martin, Ph.D.
M. McQuilling, Ph.D.
S. Minteer, Ph.D.
K. Ravindra, Ph.D.
W. Thacker, Ph.D. (person of contact)
R. Willits, Ph.D.
N. Anderson, Ph.D.; Professor, University of Liverpool, United Kingdom
Greg Comer received his B.S. in physics and mathematics from East Tennessee State University in 1984 and his Ph.D. from the University of North Carolina at Chapel Hill in 1990. He held a two-year postdoc with the Racah Institute of Physics of The Hebrew University from 1990-92 and a one-year position with the Observatory of Paris-Meudon from 1992-93. He has been on the faculty of Saint Louis University since 1993, and an Adjunct Faculty with the Department of Physics of Washington University since 1997. His main area of research is Newtonian and general relativistic multi-fluid dynamics with applications to astrophysical compact objects (eg. neutron stars) and their gravitational wave emission. The main scientific goal is to understand how superfluidity and superconductivity determine the rotational structure of neutron stars, their spectrum of oscillations, and the extent to which the oscillations result in detectable---with, say, LIGO---gravitational waves. He has published 23 refereed journal articles and 4 non-refereed book chapters, conference proceedings, and on-line arXiv preprints in this area. He is also co-author on an upcoming review on relativistic fluids for the Living Reviews in Relativity. He has also been the principal investigator on two NSF/Gravitational Physics Division grants, a visiting scientist on an EPSERC grant in the United Kingdom and the Chinese University of Hong Kong Program on Initiatives in Numerical Relativity & Astrophysics, and one of the initial recipients of a SLU 2000 Faculty Research Leave Award.Dr. R. Scott Martin
R. Scott Martin is currently an assistant professor of chemistry at Saint Louis University. Dr. Martin received his Ph.D. in analytical chemistry from the University of Missouri in 1999 under the direction of Professor Stanley Manahan. From 1999-2002 he was a NIH post-doctoral fellow with Professor Susan Lunte in the Department of Pharmaceutical Chemistry at the University of Kansas. After spending a year on the faculty at the University of Iowa, Dr. Martin moved to Saint Louis University in the fall of 2003.
Dr. Martin has published over 28 research papers, most of which deal with research involving use of microchip-based devices for studying biological systems. His research is currently funded by two grants from the National Institutes of Health. He also is a member of the Bioengineering and Biotechnology Peer Review Study Group for the American Heart Association. Dr. Martin also has adjunct appointments in the Department of Biomedical Engineering at Saint Louis University and the Department of pharmaceutical Chemistry at the University of Kansas. He is also a short course instructor for the course, “Microfluidics,” at the annual LabAutomation meeting.
Dr. Martin’s research involves the use of microchip-based analytical devices to study various biological systems. Students in his group are trained in many fields including analytical, biology and engineering. New advances in microchip-based versions of flow-based analysis, capillary electrophoresis, electrochemistry and fluorescence are being developed to probe and monitor various biological systems. Current projects include: 1) the development of a microchip-based blood brain barrier (BBB) mimic to study the effect of nitric oxide (NO) on the integrity of the BBB (in collaboration with Dr. Dana Spence, Wayne State University and supported by a grant from the NIH); 2) development of a microchip-based analysis system/reactor system to study the effect of NO on the onset of Parkinson's disease (supported by a grant from the NIH); 3) development of novel sensitive and selective methods for monitoring endogenous thiols; and 4) development of chip-based immobilized enzyme assays.
Mark McQuilling is interested in the aerodynamics of airfoils extract energy from the flow in a gas turbine engine (low-pressure turbine (LPT)), which power the compressors as well as provide auxiliary energy to the aircraft. The current industry design trend is to decrease the number of airfoils in a stage in order to reduce the weight and cost of the engine. For an equivalent amount of total work extracted, decreasing the number of airfoils increases the loading on each blade. The primary obstacle to overcome with these higher-lift designs is the accurate prediction of transition on the suction surface. In coordination with the Air Force Research Laboratory at Wright-Patterson Air Force Base, my research will explore the LPT design space with a 2D design code using state-of-the-art transition modeling to determine the limits of well-behaved, high-lift LPT airfoils. The performance of new designs will also be experimentally validated in a low-speed wind tunnel linear turbine cascade. This experimental validation will also provide additional insight into the complicated transition process occurring in the boundary layer over the suction surface of the airfoil. The ultimate goal of this work is to reduce the size, weight, cost, and fuel consumption of modern gas turbine engines.
Unmanned aerial vehicles have received a great deal of attention in the recent past, and the design trend is to keep decreasing the size of the vehicles. The fluid physics of these smaller aircraft are not yet well understood, and further research is needed in order to properly design the most efficient vehicles at such extremely small sizes. Research is planned in collaboration with Dr. Bramesfeld of the Aerospace and Mechanical Engineering Department to experimentally investigate the aerodynamics of low-Reynolds number flows around these small vehicles.
Shelley Minteer received her doctoral degree in 2000 from the University of Iowa in Chemistry. She has been on the faculty in the Department of Chemistry at Saint Louis University since 2000 and was promoted to the rank of Associate Professor in 2005. Since arriving at SLU, Dr. Minteer's research has focused on the development of efficient alternative energy sources. Her group works to improve both the transport and kinetic properties of alternative energy sources. During that time, the group has published 26 research papers and has had funding from the US Army, US Navy, US Air Force, DARPA, CIA, and the United Soybean Board.
The main focus of the Minteer Group is high power density and long lifetime biofuel cells. A biofuel cell is a type of battery that can be recharged with the addition of more fuel and utilizes enzymes as biocatalysts in order to convert chemical reactions to electrical energy. The Minteer research group has developed a powerful technique to immobilize enzymes at the electrode surface, while maintaining facile mass transport of the fuel to the enzyme. This technique has helped to stabilize enzymes for increased periods time (months instead of days) by protecting fragile enzymes in tiny pore-like structures resulting in increased power and lifetime of the biofuel cell. In addition, with this technique a wide variety of fuels can be utilized including carbohydrates, fatty acids, and alcohols.
Ph.D. in Aerospace Engineering: Pennsylvania State University
M.S. in Aeronautical Engineering: Indian Institute of Science, Bangalore
B.S. in Mechanical Engineering: National Institute of Engineering, Mysore
Research Interests: Fluid Dynamics & Buffet
Hauch, R. M, Jacobs, J. H., Dimas, C., and Ravindra, K. Reduction of Vertical Tail Buffet Response Using Active Control, Journal of Aircraft, Vol. 33, No. 3, May-June 1996.
William Thacker, Ph.D.
William D. Thacker received his Ph.D. in Physics from the University of Colorado – Boulder in 1984. He has been on the faculty of Parks College since 1989 and was promoted to the rank of Professor in 2001. Dr. Thacker currently serves as chair of the Department of Physics. For the past ten years Dr. Thacker has been working on the theory and modeling of fluid turbulence. His research has focused on:
- Turbulence in time-dependent mean flows
- The influence of compressibility on turbulent correlations involving pressure
- Development of turbulence models that incorporate transition Probability density functions for turbulence
Dr. Thacker’s research in turbulence modeling has been funded by several grants from NASA Langley Research Center.Sample Publications:
W. D. Thacker, S. Sarkar, and T. B. Gatski, “An Analysis of the Rapid Pressure-Strain Rate Correlation in Compressible Shear Flow”, in the Proceedings of the 4th International Symposium on Turbulence and Shear Flow Phenomena in Williamsburg,VA, 27-29 June 2005.
C. L. Rumsey, W. D. Thacker, T. B. Gatski, and C. E. Grosch, “Analysis of Transition-Sensitized Turbulent Transport Equations”, American Institute of Aeronautics and Astronautics Paper 2005-0523, presented at the 43rd AIAA Aerospace Sciences Meeting, January 10-13 2005, Reno NV.
C. D. Pruett, T. B. Gatski, C. E. Grosch, and W. D. Thacker, “ The temporally filtered Navier-Stokes equations: Properties of the residual stress”, Physics of Fluids, Vol. 15, pp. 2127-2140 (2003).
W. D. Thacker, T. Gatski, and C. Grosch, “Modeling the dynamics of ensemble-averaged linear disturbances in homogeneous shear flow”, Flow, Turbulence and Combustion, Vol. 63, pp. 39-58 (2000).
W. D. Thacker, T. Gatski, and C. Grosch, “Analyzing mean transport equations of turbulence and linear disturbances in decaying flows”, Physics of Fluids, Vol. 11, pp. 2626-2631 (1999).
W. D. Thacker, "A path integral for turbulence in incompressible fluids", Journal of Mathematical Physics, Vol. 38, pp. 300-320 (1997).
Dr. Willits is an associate professor at the Department of Bio-Medical Engineering. In 1999 she obtained her PhD in Chemical Engineering from Cornell University, and has been a faculty member at Saint Louis University soon after. Her research encompasses several areas in tissue engineering and biomaterials. The main research focus of the laboratory is development and optimization of novel materials to control cell function. To optimize these materials, we investigate chemical, mechanical and electrical factors that influence cell function. One area of research is the nervous system, where we are developing scaffolds to act as a support and to guide regrowing nerves. To this end, we are developing a computational model that mimics nerve growth in 3D to better optimize & design these materials. Another area is orthopedics, where, in collaboration with Dr. Bledsoe's laboratory, we are fabricating and examining materials that act as both an adhesive between bone and implant and a support to encourage bone growth and integration. In addition, we are developing materials for the cardiovascular system to control restenosis after angioplasty. More information about Dr. Willits' tissue engineering laboratory can be found at this site: http://parks.slu.edu/~willitsr/telab/.