• Publications
  • Influence
Flow regimes in a circular Couette system with independently rotating cylinders
Our flow-visualization and spectral studies of flow between concentric independently rotating cylinders have revealed a surprisingly large variety of different flow states. (The system studied has
Velocity structure functions, scaling, and transitions in high-Reynolds-number Couette-Taylor flow.
Flow between concentric cylinders with a rotating inner cylinder is studied for Reynolds numbers in the range 2x10(3)<R<10(6) (Taylor Reynolds numbers, 10 < R(lambda)< 290) for a system with radius
Localized excitations in a vertically vibrated granular layer
THE formation of two-dimensional patterns in biological, chemical and physical systems is often described by the nonlinear interaction of plane waves1. An alternative approach views patterns as
Hydrodynamic instabilities and the transition to turbulence
Strange attractors and turbulence.- Hydrodynamic stability and bifurcation.- Chaotic behavior and fluid dynamics.- Transition to turbulence in Rayleigh-Beenard convection.- Instabilities and
Collective motion and density fluctuations in bacterial colonies
This work reports simultaneous measurements of the positions, velocities, and orientations as a function of time for up to a thousand wild-type Bacillus subtilis bacteria in a colony, demonstrating that bacteria are an excellent system to study the general phenomenon of collective motion.
Dynamical instabilities and the transition to chaotic Taylor vortex flow
We have used the technique of laser-Doppler velocimetry to study the transition to turbulence in a fluid contained between concentric cylinders with the inner cylinder rotating. The experiment was
Dynamics of drag and force distributions for projectile impact in a granular medium.
The experiments and molecular dynamics simulations reveal that the mean deceleration of the projectile is constant and proportional to the impact velocity, and the probability distribution function of forces on grains is time independent during a projectile's decelerations in the medium.