Phd offer (CIFRE) - Multi-scale modelling

Phd offer (CIFRE) multi-scale modelling - H/F/X

Constellium is a world leader in the development and manufacture of high value-added aluminum products and solutions for a wide range of markets and applications, focusing in particular on aerospace, automotive and packaging. Our Research and Technology Center, C-TEC Constellium Technology Center employs about 240 people, mainly dedicated to research in the fields of casting, aluminum transformation and surface treatment. We are committed to minimizing the environmental impact of our operations and improving the environmental footprint of aluminum throughout the value chain.

Thesis subject : Multi-scale modelling of aluminium scrap stack remelting in industrial furnaces

Context : Aluminium recycling is a key pathway for decarbonisation, as secondary production requires far less energy than primary aluminium. However, the remelting of scrap or ingot stacks remains a critical step: it accounts for most of the energy consumption in recycling, generates metal losses through oxidation (“melt loss”), and involves tightly coupled physical phenomena. At the local scale, the melting of each individual element depends on complex heat‑transfer mechanisms (thermal radiation, convection, internal conduction), oxidation kinetics, and the flow and drainage of liquid metal as melting progresses. These processes occur within an evolving geometry where the scrap bed reorganises and the metal/atmosphere interfaces change continuously throughout the cycle.

Objective : The aim of this PhD is to develop a multi‑scale modelling framework to describe the remelting of aluminium scrap beds in industrial furnaces, linking the local melting behaviour of individual fragments to the thermal and geometric evolution of the entire bed. The work will focus on improving the understanding of radiative, convective and conductive heat transfer in a complex, evolving geometry, as well as oxidation mechanisms responsible for melt loss, in order to deliver a predictive model suited to industrial needs.

Methods : The project will first rely on high‑fidelity numerical simulations describing the local melting of aluminium fragments, accounting for radiative, convective and conductive heat transfer, solid–liquid interface evolution, and surface oxidation leading to melt loss. These simulations will then support the development of a homogenised model representing the macroscopic behaviour of a full scrap bed subjected to the thermal conditions of an industrial furnace. The work will consist in consistently linking local mechanisms to effective large‑scale properties, and validating the resulting models against representative industrial scenarios provided by Constellium.

We are looking for a highly motivated candidate with an Engineering degree or a Master's degree in thermal engineering, mechanical engineering, physics or process engineering, with a strong interest in numerical modelling and heat transfer.

• Starting date : October 2026 
• Duration : 3 years
• Host laboratories : EM2C – CentraleSupélec / Université Paris‑Saclay (80–90%) and Constellium C‑TEC, Voreppe (10–20%, with possible adjustments depending on the phase of the PhD)
• Academic supervision : Aymeric Vié (EM2C), Morgan Chabanon (EM2C), Benoît Rousseau (LTeN)
• Industrial supervision : Louis Piquard (Constellium), Pierre Celle (Constellium), Bernard Labegorre (Air Liquide), Jean Caudal (Air Liquide)