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Job Record #16631
TitleLiquid fluidization of cylindrical particles : DNS
CategoryPostDoc Position
EmployerIFP Energies Nouvelles
LocationFrance, Lyon
InternationalYes, international applications are welcome
Closure DateSaturday, August 01, 2020
Description:
The World’s increasing energetic demands are causing a rapid consumption of 
fossil reserves. To reply to this problematic, the industry’s main route in 
future may comprise the upgrading of heavy crude oils or increasing use of 
biomass resources like bio-oils. To do so, one of the available technologies 
is a catalytic solid-liquid-gas fluidized bed reactor. In these devices, a 
bed of particles is fluidized by an ascending flow of liquid or gas. The 
particles generally used in this kind of devices are slender extrudates of 
cylindrical shape. These particulate flows are widely encountered in many 
other industrial processes (catalytic, adsorption, combustion reactors, 
fermentation, etc). Mastering and controlling these complex industrial 
devices require at first a better understanding of the intricate multiscale 
hydrodynamics couplings at play between both solid and liquid phases in the 
specific case of anisotropic particles. Such knowledge has to be searched 
for to develop new models for Computational Fluid Dynamics (CFD) codes that 
will lead to more adapted designs of industrial units that could, in 
particular, achieve lower energy consumption and environmental footprint.
The aim of the present post-doc position, which is part of a larger research 
project (ANR MUSCATS), is to better understand the hydrodynamics in 
fluidized beds made of cylindrical particles. Many studies have focused on 
the liquid fluidization particles ( or sedimentation process depending on 
the frame of reference) of spherical particles. Duru & coworkers (2002) 
investigated experimentally the flow in a liquid fluidized bed. They 
identified continuity waves that were reproduced numerically by Derksen &  
Sundaresan (2007).  Yin & Koch (2007) investigated numerically the micro-
structure of the dispersed phase for moderate volume fraction. More recently 
Almeras et al. (2019) have proposed a model to describe the fluctuations in 
inertial dense homogeneous suspensions of spherical particles.  However, 
there are much less studies dedicated to the flow in fluidized beds made of 
cylindrical particles.
To this aim, the PeliGRIFF code 
(http://projet.ifpen.fr/Projet/jcms/xnt_11465) and in particular its DLM/FD 
module (see Wachs et al. C&F 2015) will be intensively used to compute the 
flow in fixed and fluidized beds of cylindrical particles. This code has 
been widely validated by the past on liquid fluidized beds of spherical 
particles (Esthegamatian et al., PoF 2017) and fixed beds of cylindrical 
particles (Dorai et al., CES 2015). It is thus perfectly suited for this 
kind of applications. The post-doctoral candidate will start with the 
computations of the fixed bed of cylindrical particles [T0:T0+6months]. He 
(she) will pay particular attention to the forces and torques acting on the 
cylindrical particles. These informations are of particular interest for 
Euler-Lagrange and Euler-Euler simulations performed by a PhD student who is 
also part of the MUSCATS project. Then [T0+6months:T0+12months] the post-
doctoral candidate will perform DNS of cylindrical particles settling in a 
triperiodic box. The post-doc candidate will implement the lubrication force 
between two cylindrical particles as in the work of Butler & Shaqfeh (2002). 
This step is mandatory to accurately catch the hydrodynamic interactions in 
dense fluidized beds. The remainder of the post-doc will be dedicated to 
intense computations of the fluidized bed in both moderately dense and dense 
configurations.  He will particularly focus on the detailed statistics of 
the flow (radial distribution function, ...) as well as the modification of 
evolution of the sedimentation velocity as function of the volume fraction. 
The final aim of the project is, of course, to publish the main results in 
the best journal of the field (Journal of Fluid Mechanics, Physical Review 
Fluids etc).

The post-doctoral candidate must meet the following requirements: PhD degree 
in fluid mechanics or applied mathematics, computer science, physics, or 
equivalent. Knowledge of computational fluid dynamics and C++ are an 
advantage.  IFP Energies Nouvelles offers a stimulating interdisciplinary 
environment combining applied mathematics, fluid mechanics and chemical 
engineering. The successful candidate will take advantage of a fruitful 
collaboration with Olivier Simonin (IMFT) as part of the ANR MUSCATS. The 
net salary is closed to 2300€ per month.

Bibliography

Alméras, É., Masbernat, O., Risso, F., & Fox, R. O. (2019). Fluctuations in 
inertial dense homogeneous suspensions. Physical Review Fluids, 4(10), 
102301.
Butler, J. E., & Shaqfeh, E. S. (2002). Dynamic simulations of the 
inhomogeneous sedimentation of rigid fibres. Journal of Fluid Mechanics, 
468, 205-237.
Derksen, J. J., & Sundaresan, S. (2007). Direct numerical simulations of 
dense suspensions: wave instabilities in liquid-fluidized beds. Journal of 
Fluid Mechanics, 587, 303-336.
Duru, P., Nicolas, M., Hinch, J., & Guazzelli, E. (2002). Constitutive laws 
in liquid-fluidized beds. Journal of Fluid Mechanics, 452, 371-404.
Duru, P., & Guazzelli, É. (2002). Experimental investigation on the 
secondary instability of liquid-fluidized beds and the formation of bubbles. 
Journal of Fluid Mechanics, 470, 359-382.
Sanjeevi, S. K., & Padding, J. T. (2020). Hydrodynamic forces on 
monodisperse assemblies of axisymmetric elongated particles: Orientation and 
voidage effects. AIChE Journal, 66(6), e16951.




Contact Information:
Please mention the CFD Jobs Database, record #16631 when responding to this ad.
NameJean-Lou Pierson
Emailjean-lou.pierson@ifpen.fr
Email ApplicationYes
Record Data:
Last Modified17:29:30, Tuesday, June 16, 2020

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