PDF2008 "Polymer and surface roughness effects on the drag crisis for falling spheres"
Lyotard, N, Shew, WL , Bocquet, L, & Pinton JF, Euro. Phys. J. B60, 469
PDF2007 "Lagrangian temperature, velocity and local heat flux measurement in
Rayleigh-Benard convection" Gasteuil, Y, Shew, WL , Gibert, M, Chilla, F, Castaing, B, & Pinton JF, [COVER]Phys. Rev. Lett.99, 234302
PDF2007 "An instrumented tracer for Lagrangian measurements in Rayleigh-Benard
convection" Shew, WL , Gasteuil, Y, Gibert, M, Metz, P, & Pinton JF, Rev. Sci. Instruments
PDF2006 "Force measurements on a rising bubble"
Shew, WL, Poncet, S and Pinton, JF, J. Fluid Mech.569, p. 51
PDF2006 "Dynamical model of bubble path instability"
Shew, WL and Pinton, JF, Phys. Rev. Lett.97, 144508
PDF2006 "Viscoelastic effects on the dynamics of a rising bubble."
Shew, WL and Pinton, JF, J. Stat. Mech. January, P01009
PDF2005 "Liquid sodium model of geophysical core convection"
Shew, WL, and Lathrop, DP, Phys. Earth Planet. Int.153, p. 136
PDF2003 "Lorentz force effects in magnetoturbulence"
Sisan, DR, Shew, WL, and Lathrop, DP, Phys. Earth Planet. Int.135, p. 137
2002 "Mechanically forced and thermally driven flows in liquid sodium"
Shew, WL, Sisan, DR, and Lathrop, DP, Magnetohydrodynamics38, p. 121
2001 "Laboratory experiments on the transition to MHD dynamos" Lathrop, DP,
Shew, WL, and Sisan, DR, Plasma Phys. and Controlled Fusion43, p. 151-A160 Suppl. 12A
PDF1999 "Taming chaos with disorder in a pendulum array" Shew, WL, Coy, H,
and Lindner, JF, Am. J. Phys.67, p. 703
We have developed flow tracing particles with on-board measurements (e.g. acceleration, temperature) and wireless communications systems (RF). These particles may be used to make Lagrangian measurements in a broad range of laboratory and natural fluid flows. We have made quantitative measurements heat Lagrangian transport of thermal plumes in Rayleigh-Benard convection. (with Y. Gasteuil, M. Gibert, and J.-F. Pinton at ENS Lyon)
Neuronal Networks
Using a two-photon microscope and multi-electrode arrays we study patterns of activity in neuronal networks
in rat cortex. Our aim is to understand the basis of neuronal avalanches in large neuronal networks with single cell resolution.
(with D. Plenz at National Institutes of Health)
3-D Imaging of Neurons
We are developing a novel two-photon microscopy technique for imaging three-dimensional groups of neurons simultaneously. The project is a
collaboration between University of Maryland and National Institutes of Health with Rarjarshi Roy and Dietmar Plenz
Continuous ultrasound and high speed cameras are used to measure the three dimensional trajectory of air bubbles in water. The ultrasound method provides direct and very sensitive velocity measurements. We deduce quantitative measurementsof the forces on the bubbles from the peculiar zigzagging and spiraling bubble trajectories. We have developed a simple dynamical model for these motions based on our measurements. We have also explored viscoelastic effects on these dynamics with bubbles rising in non-Newtonian fluids. (with J.-F. Pinton at ENS Lyon)
The motion of the molten iron of Earth's outer core was modelled with a 60 cm diameter, rapidly rotating, spherical convection experiment. The titanium vessel contained 100 liters of molten sodium and rotated at rotation rates up to 30 RPS and sustained up to 5 kW of heat transfer. Our results allowed us to estimate the size of convective velocities, time and length scales, ohmic dissipation, as well as the Rayleigh number for the Earth's outer core. (with D. P. Lathrop at UMD)
Molten sodium was driven into a highly turbulent state in the presence of large magnetic fields (up to 0.2 T). As the applied magnetic field is increased, Lorentz forces become large enough to significantly suppress the turbulence. For large enough magnetic fields, instabilities arise in the interactions between the fluid flow and the magnetic field, exhibiting regular patterns in the induced magnetic field. These instabilities may be a laboratory manifestation of the magneto-rotational instability. (with D. R. Sisan & D. P. Lathrop at UMD)
An experimental array of 10 coupled pendulums with sinusoidal forcing was used to explore the control of chaos in spatially extended systems. It was found that the system behaved chaotically when all the pendulums were identical and could be pushed into a periodic state by randomly adjusting their lengths; adding disorder tames the chaos. (with J. F. Lindner at COW)