Abstract:
Fluidized beds are a particular hydrodynamic configuration in which a pack
(either dense or loose) of particles laid inside a container is re-suspended as
a result of an upward oriented imposed flow at the bottom of the pack. This kind
of system is widely used in the chemical engineering industry where catalytic
cracking or polymerization processes involve chemical reactions between the
catalyst particles and the surrounding fluid and fluidizing the bed is
admittedly beneficial to the efficiency of the process. This process has been
extensively investigated from the hydrodynamic standpoint and valuable
stationary features have been provided (fluidization velocity, mean bed height,
...). The objective of this PhD is to go one step further into the deep
understanding of this class of inertia dominated fluid/solid flows by resorting
to employing a multi-scale analysis and high performance computing. Essentially,
we will survey fluidized beds dynamics at the micro and meso scales with the
appropriate models, basically fully resolved high fidelity simulations for the
former and DEM-CFD simulations for the latter. We expect to perform
unprecedented direct numerical simulations (DNS) on grids in which the number of
unknowns is of the order of a few billions. The analysis of this huge set of
data will require appropriate tools to visualize the subtle characteristics of
the flow as well as to extract the relevant statistics. Not only DNS data will
provide new insight into the heart of the flow, a knowledge that is usually
inaccessible by experiments with non-intrusive measurements, but they will also
give new directions towards the improvement of meso (and possibly macro) scale
models, in the spirit of an upwards cascade of knowledge from the small to the
large scales.

Keywords: 
Fluid Mechanics; Particulate Flows; Numerical Simulation; Scientific
Programming; High Performance Computing

Academic supervisors: 
Prof. Michel Lance, LMFA (Laboratoire de Mécanique des Fluides et d'Acoustique),
Lyon, France and Prof. Markus Uhlmann, Turbulent Flow Group, Institute for
Hydromechanics, KIT, Karlsruhe, Germany.

Doctoral School: 
ED MEGA, Lyon, http://edmega.universite-lyon.fr/.

IFPEN supervisor: 
Dr. & IFPEN Scientific Advisor Anthony Wachs, Fluid Mechanics Department, IFPEN,
Lyon, France, email: anthony.wachs@ifpen.fr.

IFPEN website job announcement: 
http://www.ifp-school.com/default.asp?id=45&thesis=70&these=75


Location: IFP Energies nouvelles, Lyon, France.
Duration: 3 years
Starting date: October 1st, 2013.
Salary: around 2000€ net per month.


IFPEN offers a stimulating research environment, with access to powerful
computing facilities (both its owns and national supercomputers) as well as a
competitive salary and benefits. The position is open in the Fluid Mechanics
Department, and more specifically in the Computational Multiphase Flow Group
(www.peligriff.com) led by Dr. Anthony Wachs.