For the various positions possibly available in the group, please click on the links below:
Internship positions
Title: Numerical study of cavitation and pinning effects due to gas injection through a bed of particles: application to a radial-flow moving-bed reactor
Abstract:
The context is the petroleum and chemical industries, in which radial-flow moving-bed reactors are used to carry out chemical reactions such as catalytic reforming. Radial-flow reactors provide high capacity without increased pressure drop or greatly increased vessel dimensions. This is done by holding the catalyst in a basket forming an annular bed, and causing the gas to flow radially between the outer annulus and the central tube. Catalyst enter the top of the reactor and move through the vessel by gravity. Once at the bottom the catalyst is removed and regenerated.
Within the catalytic bed, the combined effects of particles motion and radial injection of the gas may lead to cavitation and pinning phenomenon that may clearly damage the reactor. Several theoretical and experimental studies have already been conducted in IFPEN in order to understand the way cavitation and pinning occur.
The objective of the internship is to study both cavitation and pinning effects using an in-house numerical software, named PeliGRIFF (http://www.peligriff.com/), designed to simulate particulate flows at different scales; from the particle scale (or micro scale), using Direct Numerical Simulation (DNS) to solve fluid/particle interactions, to the particles suspension (or meso scale) where the fluid/solid interactions are modeled. Simulations involving a few millions of particles aiming at reproducing experimental experiments, will be run on supercomputers and analyzed. The work program of the internship could be organized as follows:
- Literature review, mechanical problem analyzing, PeliGRIFF familiarization
- Run simulations
- Results analysis and comparisons with experimental results
- Write a research report
IFPEN supervisor: Dr. Guillaume VINAY, IFPEN, Rueil Malmaison, France.
Location: IFP Energies nouvelles, Rueil Malmaison (France)
Starting date: February/March 2016
Duration: 5-6 months
Academic requirements: University master degree student or 3rd year engineering school
Language requirements: Fluency in English, knowledge of French appreciated but not mandatory
Other requirements: Fluid mechanics, numerical simulation, scientific computing, Linux
Contact: guillaume.vinay@ifpen.fr
PhD positions
There is currently one open PhD position in the PeliGRIFF group:
Title: Theoretical and numerical study of the forces acting on slender particles
Abstract:
Fluidized beds consists of suspended particles under the action of an upward flow. This kind of situation is frequently encountered in various industrial processes such as catalyze and biomass gasification. Despite the large numbers of studies describing the fluidization of spherical particles, much less is known concerning fluidization of non-spherical particles. In order to characterize these flows Euler-Lagrange description is frequently used. For this purpose hydrodynamic forces acting on the particles are needed. The goal of this work is to develop a predictive model for the hydrodynamic forces and torques acting on slender particles. To this aim we will intensively make used of direct numerical simulation to analyse this problem in different flow and physical configurations. At the same time theoretical models will be developed using perturbation methods. One in the Oseen limits (inertia effects smaller than viscous) and one under the boundary layer approximation. Results obtained analytically and from numerical simulations will be used in Euler-Lagrange simulations in order to compute semi-industrial fluidized beds.
Academic supervisor: Pr. Jacques Magnaudet, IMFT, Toulouse, France.
IFPEN supervisor: Dr. Jean-Lou Pierson, IFPEN, Lyon, France.
Location: Solaize (France)
Starting date: from October 2017
Duration: 3 year.
Academic requirements: Multiphase Fluid Mechanics and numerical code development
Language requirements: Fluency in English, knowledge of French appreciated but not mandatory
Other requirements: Fluid mechanics, experience in C/C++ programming, Linux, Scientific computing
Contact: jean-lou.pierson@ifpen.fr
Download the job annoucement here.
Post-doc positions
There is currently one open post-doc position in the PeliGRIFF group:
Title: Meso scale Euler/Lagrange modelling of reactive particulate flow in complex geometry : Multi-scale analysis and applications
Abstract:
Many industrial processes like coal combustion, catalytic cracking, gas phase polymerization reactors and more recently biomass gasification and chemical looping involve two-phase reactive flows in which the continuous phase is a fluid and the dispersed phase consists of rigid particles. Improving both the design and the operating conditions of these processes represents a major scientific and industrial challenge in a context of markedly rising energy cost and sustainable development. Thus, it is above all important to better understand the coupling of hydrodynamic, chemical and thermal phenomena in those flows in order to be able to predict them reliably. The current post-doc position is offered in the framework of the MORE4LESS collaborative project supported by ANR (French National Research Foundation). The aim of MORE4LESS is to build up a multi-scale modelling approach of reactive particulate flows and to focus on the development of a mesoscopic-scale Euler/Lagrange (MSEL) model including heat and mass transfers and chemical reactions for the prediction of particle-laden flows in dense and dilute regimes. This new modelling will be implemented in a massively parallel numerical code that will enable us to take a step towards the enhanced design of semi-industrial processes.
The goal of the post-doc work is to validate our novel meso-scale numerical tool as well as fulfil the full multiscale analysis by comparison with experimental data. The first-step validation of the new numerical tool will be to compare results from the 3D unsteady Euler/Lagrangian simulations against experimental data from the non-reactive isothermal fluidized bed pilot at Birmingham (Fede et al., 2009, 2011). The second-step validation of the new tool will be to compare results from Euler/Lagrangian numerical simulations against experimental data from the reactive fluidized bed pilot at Toulouse (LGC, Laboratoire de Genie Chimique, UMR 5503 INPT/CNRS/UPS).
This new tool will open up new perspectives in the comprehension of the dynamics of fluidized beds and we forecast to perform unprecedented simulations. This will give us strong opportunities to publish this work both in Multiphase Flow and High Performance Computing journals.
Academic supervisor: Pr. Anthony Wachs, UBC, Vancouver; CNRS Researcher Dr. Masi Enrica, IMFT
IFPEN supervisor: Dr. Abdelkader Hammouti, IFPEN, Lyon, France.
Location: Solaize (France)
Starting date: from September 2017
Duration: 1 year.
Academic requirements: PhD in Multiphase Fluid Mechanics and numerical code development
Language requirements: Fluency in English, knowledge of French appreciated but not mandatory
Other requirements: Strong experience in mass and heat transfer, hydrodynamics and thermodynamics, experience in C/C++ programming, Linux
Contact: abdelkader.hammouti@ifpen.fr
Download the job annoucement here.
Scientific visitors
IFPEN offers nice research facilities, a stimulating environment as well as an appropriate financial support for leading academic researchers to come for a scientific stay for a period of time ranging from 3 months to a full year. Please visit the following webpage for additional information on the IFPEN website.
In the PeliGRIFF group, we have a tradition of hosting scientific stays of academic researchers. Would you be interested to join our group for a few months during a sabbatical leave, please do not hesitate to contact us, such positions are constantly open at IFPEN.