ECOLE DOCTORALE SI-MMEA
(http://simmea.ed.univ-poitiers.fr/)
Proposition de sujet de thèse
pour contrat doctoral 2016
LABORATOIRE
Etablissement
TITRE en français
Site Poitiers :
P’D1*
P’D2*
P’D3*
Site Limoges :
 SPCTS*
GEMH*
Site La Rochelle :
LaSIE*
UP*
ENSMA*
UL*
ENSCI*
ULR*
Développement d'un modèle physique du fonctionnement d'une torche à plasma d'arc
de projection
TITRE en anglais
Towards a physics-base reliable model of plasma spray torch operation
Résumé en français (300 caractères
maximum)
Le sujet de thèse porte sur la modélisation 3-D instationnaire d’une torche à plasma d’arc
non transféré. Il s’intéresse à la résolution des équations de Navier et Stokes couplées à
celles de l’électromagnétisme et vise à prendre en compte les effets de la géométrie
interne de la torche sur le comportement de l’arc et les champs de vitesse et de
température du jet en sortie de torche. Il intègre le couplage thermique et
électromagnétique entre les électrodes et l’arc.
Résumé en anglais (300 caractères
maximum)
The PhD topic deals with a 3-D and time- dependent modeling of a DC non transferred
plasma torch. It is based on the solution of the Navier-Stokes equations coupled with
electromagnetic equations. It aims to investigate the effect of the torch inner geometry
on the arc behavior and the velocity and temperature fields at the plasma torch nozzle.
exit. It integrates a thermal and electromagnetic coupling between the arc and
electrodes.
Plasma spray is regarded as a key surface engineering technology that underpins the
competitiveness of many critical manufacturing and engineering industries (e.g.
aeronautics and energy production industry). The primary component of the process is
the plasma torch. However, the conventional plasma torches (mono-cathode and monoanode) widely used in industry, suffer from arc instability, electrode erosion and radial
injection of powder. The development of more robust plasma torches, in particular for
the emerging plasma spray processes (suspension and solution plasma spraying and very
low pressure plasma spray) requires a deep understanding of the arc phenomena within
the plasma torch. As the measurements inside the torch are limited, mathematical
modeling is essential for further development of plasma torches whose operation is
controlled by thermal, electromagnetic, acoustic and chemical phenomena.
The present plasma spray torch models simultaneously solve the Navier-Stokes equations
(gas mass, momentum and species), energy conservation equation (gas temperature) and
the Maxwell equations (electric and magnetic fields). The more advanced models make it
possible to predict the three-dimensional and time-dependent operation mode of the arc
within the plasma torch and gas flow fields inside the plasma torch and in the plasma jet;
they can also take into account the thermal non- equilibrium that prevails close to the
electrodes. However, before plasma torch operation models prove their predictability,
some stages have to be reached and in particular use of the inner actual geometry of the
torch (essential to model the acoustic resonance phenomenon inside the plasma torch
due to compressibility effects of the plasma-forming gas) and reliable thermal and
electromagnetic coupling of electrodes and electric arc. They are both essential to
increase the level of predictive capability of the model so that everyone believes in the
predictions and use them to develop and/or improve plasma torch design and operation
without further experimental experience.
The objective of this work is to develop a 3-D and time-dependent model of a plasma
spray torch that integrates the actual geometry of the plasma torch necessary to take
Descriptif (2000 caractères
maximum)
Cotutelle ?
Si cotutelle
Directeurs de thèse (HDR)
Taux d’encadrement prévu (%)
Co-encadrant
Taux d’encadrement prévu (%)
Contact pour informations
complémentaires
Type de master requis
into account the acoustic phenomena. This implies to work with a compressible
computational fluid dynamics software. Predictions will be carefully validated against
experimental data obtained in this laboratory with dedicated experiments under the
same torch operation conditions
oui
non
Etablissement :
Ville :
Pays :
NOM : RAT Prénom : Vincent Laboratoire : SPCTS (33%)
NOM : Vardelle Prénom : Armelle Laboratoire : SPCTS (33%)
NOM : Chazelas Prénom : Christophe Laboratoire : SPCTS (33%) HDR ?
non
Email : [email protected]
oui
Tel : 05 55 42 36 70
MSc in Mathematical Modelling and Scientific Computing or MSc in Physics and
applications or MSc in Fluid dynamics and energetics
*Sigle : P’D1, P’D2 et P’D3 : Départements D1, D2 et D3 de l’institut P’ : http://www.pprime.fr/; SPCTS :
http://www.unilim.fr/spcts/; GEMH : http://www.avrul.fr/spip.php?rubrique39; LaSIE : http://www.univ-larochelle.fr/LaSIE, UP
http://www.univ-poitiers.fr/,
ENSMA
http://www.ensma.fr/,
UL
:
http://www.unilim.fr/