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Reference : UMR7641-NASNAA-007
Workplace : PALAISEAU
Date of publication : Tuesday, April 27, 2021
Type of Contract : FTC Scientist
Contract Period : 10 months
Expected date of employment : 18 May 2021
Proportion of work : Full time
Remuneration : Depending on experience the gross monthly salary will be between 2728€ et 3881€
Desired level of education : PhD
Experience required : Indifferent
In this post-doctoral work on the project "Analysis of hydrodynamic instabilities in the melt pool in SLM",we propose a hybrid approach associating simplified calculation and detailed computations, in order to obtain a model sufficiently fast to investigate melt pool instabilitiesin the space of process parameters,and to characterize resulting defects
Within this framework, we are interested in determining by numerical simulation the boundaries that define a zone without defects.Defects are in general of four different kinds.
keyhole, humping, balling, lack-of-fusion.
To do so, a simplified and fast code of thermalconduction(relying on finite difference discretization)is available.This code neglects hydrodynamics contributions in the heat equation, but enables us to compute the melt pool geometry and temperature in the conduction zone(i.e., in the zone without instability). One can therefore estimatethe residual porosityand productivity by overlapping the melt poolgeometry for the differentlayers. The validityof such a modelbeing very limited in the melt poolforvarious process parameters, wepropose a coupling betweenthis simplified model and another existing model including fluid dynamics and the computation of instabilities. This second model called BASILIK relies on embeddedboundaries andvolume of fluid discretization..
-Couple and extend existing models
-Map the boundaries of instabilities in the power-speed diagram
-Propose new strategies to increase productivity under quality constraints
The applicant shouldhaveobtainedaPhDdegree, and his or her area of expertiseshouldbecentered on fluid mechanics and especially theoretical and numerical aspects.
This project is funded within the framework of SOFIA project leaded by AddUp. It will be held in Ecole Polytechnique withinSolidMechanics Laboratory (LMS)and LadHyX, with frequent interaction with differentpartners in the SOFIA project.
Daniel Weisz Patrault(firstname.lastname@example.org, LMS)
Eric Charkaluk(email@example.com, LMS)
Christophe Josserand(firstname.lastname@example.org, LadHyX)
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