THE LEVICH INSTITUTE ANNOUNCES THE FOLLOWING SPECIAL SEMINAR
Friday, 11/20/98
2:00 PM
Steinman Hall, Room #1M-22
Dr. Jean-Pierre Hulin
Centre National de la Recherche Scientifique (CNRS)
"Density Waves in Granular Flow"
ABSTRACT
An experimental study of the space and time variations of vertical dry granular flows in a pipe will be presented. Transitions between flow regimes are induced by controlling the granular flow rate or inducing an adverse pressure gradient. Flow rate, pressure and compacity measurements are combined with the spatio-temporal diagrams providing information on the perturbations induced in the flow and their propagation velocities. High flow-rate regimes are characterized by high granular velocities, and low compacities induce large downward air flows and significant under pressures at the top part of the flow. At low flow rates, the flow is slow and of high compacity: intermittent regimes inducing moving decompaction waves may be observed. At compacity clogs and low compacity bubbles are propagating at a constant or periodically varying velocity. Variations of the pressure gradients and of the compacity distributions are analyzed as a function of the granular and air flow-rates: a 1D model allows us to estimate the influence of the interactions of particles with air and with the tube walls.
BRIEF ACADEMIC/EMPLOYMENT HISTORY:
- 1968 Agregation, Physical Sciences (4th Rank)
- 1973 State Thesis in Condensed Matter Physics
- 1968-75 Assistant Professor, Physics (ENS, Paris)
- 1975-78 Adjunct Director, Physics Laboratory (ENS)
- 1978-83 Program Leader and Section Head, EPS Schlumberger
- 1983-85 Assistant Professor in Physics (ENS-Paris)
- 1985-90 Charge de Recherches, CNRS (SPI Dept - 11th Section)
- 1990- Director of Research, CNRS (SPI Dept - 10th Section)
RESEARCH INTERESTS:
- Structure and transport properties of fractures
- Tracer dispersion and miscible fluid
- Displacements in heterogeneous porous media;
- Flow of non-Newtonian fluids through porous media
Return to Fall, 1998 Seminar Schedule