Martin Maxey
Professor:
Applied Mathematics
Phone: +1 401 863 1482
Phone 2: +1 401 863 1414
Martin_Maxey@Brown.EDU
Professor Maxey's research in fluid dynamics is focused on dispersed two-phase flows such as suspensions of particles in liquids. Current applications of interest include self-assembly in micro-scale flows, swimming of single cell organisms and blood flow. Other research areas include turbulent flows and mixing with applications to physical and geophysical systems.
Biography
Professor Maxey completed his undergraduate and graduate education at the University of Cambridge and received his Ph.D. in Applied Mathematics and Theoretical Physics in 1979. In 1977, he was a pre-doctoral research fellow in the Geophysical Fluid Dynamics Summer Program at Woods Hole Oceanographic Institute. He held a post-doctoral position in the Department of Mechanics and Materials Science at the Johns Hopkins University and subsequently was a lecturer in the Department of Chemical Engineering at Johns Hopkins. He joined the Division of Applied Mathematics at Brown University in 1982. He is presently Professor of Applied Mathematics and Engineering and since 1991 has served as Director of the Center for Fluid Mechanics, Turbulence and Computation. He is a member of the editorial board for the International Journal of Multiphase Flow, an associate editor for Fluid Dynamics Research, and is a fellow of the American Physical Society.
Interests
Recent research projects include methods for turbulent drag reduction, the manipulation of small paramagnetic particles with magnetic fields to form self-assembled structures in a suspension, active suspensions of microorganisms or artificial swimmers, and problems relating to the transport and coagulation of platelets in blood flow. In these projects, we have developed direct numerical simulations and theoretical models that characterize the microstructure and help understand the overall processes.
In a Defense Advanced Research Projects Agency (DARPA) sponsored project aimed at reducing drag on ship hulls, we have been studying the dynamics of micro-bubbles injected into turbulent shear flows and how these may alter the near-wall flow. The technique of micro-bubble injection is known to work in laboratory experiments but there has been little theory as to how drag reduction is achieved or how it might be scaled. Previously we had provided the first demonstration of drag reduction through a direct numerical simulation. We have developed new simulations for spatially-developing channel flows that now provide a direct basis for comparison with experiments. Our simulations have further identified bubble-bubble contacts as an important factor in bubble dispersion, which in turn controls the persistence of drag reduction. Drag reduction may be enhanced by the presence of a gas film at the walls. Papers on this work were presented at the 2nd Int. Symp. Seawater Drag Reduction, held in Busan, South Korea in 2005.
With National Science Foundation support, we are studying the dynamics of paramagnetic beads in suspensions. These beads (~ 1 micron in size) are commonly used in biomedical testing and can be treated to respond to biochemical agents. When in suspension they can be manipulated by magnetic fields to form self-assembled structures such as chains that can be used in micro-devices to create optical filters, or as flow pumps and actuators. They can be used also to produce mixing in a fluid, or for manipulating individual cells in biomedical applications. We have developed new simulation methods to accurately predict the interactions between magnetic beads. We have demonstrated the strong role of 3D-geometry of the flow device on the chains that form, and verified these results against available experiments. We are presently investigating the effects of unsteady or rotating magnetic fields. Surface physics and short-range interactions play a role too. We have been using molecular dynamics (MD) simulations and the dissipative particle dynamics (DPD) to investigate the link between these nano-scale and mescopic features to link them to larger scale simulations.
In a new project, we are studying the dynamics of platelet coagulation in blood flow in both large blood vessels and in small capillaries.
Awards
Fellow, American Physical Society, elected September 2005
Japan Society for the Promotion of Science, Invited Research Fellow, 1997
Affiliations
American Geophysical Union
American Physical Society
American Society of Mechanical Engineers
Sigma Xi
Society for Industrial and Applied Mathematics (SIAM)
Society of Rheology
Editorial Board – International Journal of Multiphase Flow
Teaching
Fluid dynamics and topics courses relating to applications of fluid mechanics such as biophysics and biomechanics, physical oceanography, and complex fluids.
Mathematical methods of applied mathematics
