MSCA COFUND PhD@Tec21 - PhD position in Fluid Dynamics: Developing multiphysics VOF DNS for the fragmentation and solidification of low-Prandtl jets

Universite Grenoble Alpes; France; On-site; EUR 23,000 - 24,000; Full time

Benefits offered by this job

36-month contract

HPC access and equipment

120 hours of doctoral courses

Secondments to partner institutions

Visa and housing support

Paid holidays

Job summary

Université Grenoble Alpes is offering a 36-month PhD position focused on multiphase flow dynamics in Laser Powder Bed Fusion. The PhD project combines DNS on HPC with data-driven approaches to understand droplet formation, cooling, and solidification in metallic powders.

Supervisors include leading experts in multiphase flows and imaging techniques. The position is funded under the COFUND Marie Curie programme (Horizon Europe) and includes a competitive gross salary with full social benefits.

Qualifications

• Experience in scientific computing and HPC
• Strong background in numerical methods and CFD
• Ability to work with large datasets and post-processing

Responsibilities

• Perform DNS of jet fragmentation on HPC
• Develop solvers for droplet solidification
• Analyze droplet statistics and scaling laws
• Collaborate with supervisors and Tec21 labs

Skills

Python

C++

Bash programming

HPC computing

Large data management

Code versioning

Education

Master’s degree in Engineering or Applied Science

Tools

Elmer

OpenFOAM

Basilisk

Job description

Organisation/Company Universite Grenoble Alpes Department COFUND PhD_at_Tec21 Research Field Physics Researcher Profile First Stage Researcher (R1) Positions PhD Positions Application Deadline 28 Feb 2027 - 13:00 (Europe/Paris) Country France Type of Contract Temporary Job Status Full-time Offer Starting Date 1 Oct 2027 Is the job funded through the EU Research Framework Programme? Horizon Europe – COFUND Marie Curie Grant Agreement Number 101217261 Is the Job related to staff position within a Research Infrastructure? No

Offer Description

Context and work environment

Laser Powder Bed Fusion (LPBF) is an advanced additive manufacturing process, critical from medical implant production to aerospace applications, whose accuracy and relevance ultimately rely on the quality of the metallic powder to be melted. The properties of the material manufactured via LPBF directly depend on the powder flowability, governed by the size and the sphericity of the solid particles. Metallic powders are commonly produced by gas-assisted atomisation of liquid metal jets , but the dispersion of the size and sphericity of the resulting droplets is not sufficiently controlled yet. A better understanding of the balance between interfacial dynamics and the cooling and solidification dynamics is necessary to complement the scarce literature on the fragmentation, cooling, and solidification of liquid metal (low‑Prandtl) jets.

The objective of this PhD project is to bridge the gap in simulating the multiphysics of liquid metal jet fragmentation, from the inductive melting of the feedstock to droplet solidification, including primary and secondary atomization as well as heat transfers between the continuous and dispersed phases. The PhD student will conduct numerical investigations on H igh- P erformance C omputers (HPC) to run Volume-Of-Fluid (VOF) Direct Numerical Simulations (DNS) and generate data necessary for deciphering the microphysics at play. A specific focus will be put on deriving the droplet statistics (size, velocity, shape, temperature) as well as the scaling laws that govern droplet cooling.Effortsfor building numerical solvers able to describe phase change and tackle droplet solidification will be carried out , leveraging and taking part in the community work around the state-of-the-art open-source solver Basilisk .

The PhD will take place within two Tec21 labs located on the Grenoble campus:

• Geophysical and Industrial flows lab (LEGI), specifically the EDT team, which has a strong and broad expertise in multiphase and turbulent flows, both experimentally and theoretically , and will benefit from collaborations with Clélia Couchet (SIMaP, GPM2 team) whose research focuses on the derivation of operating parameters set to produce well‑controlled metallic glasses via LPBF. The project will also benefit from the theoretical and numerical expertise of Olga Budenkova (SIMaP) on inductive melting flows and of an experimental liquid metal fragmentation set‑up, developed by the PIs with the support of A. El Bakali (lead engineer, SIMaP), that will be used as a benchmark for the numerical development s .

The PhD will be supervised by Romain Vallon (SIMaP), expert in DNS of multiphase flows on HPC and in modelling interfacial flows as well as fluid particle statistics, and Nathanaël Machicoane, expert in imaging techniques and their quantitative processing (e.g., sizing, tracking,and velocimetry), with a strong theoretical background on fragmenting jets, turbulence, and interfacial transfers. This team brings together a wide range of expertise in the physical mechanisms relevant to the fragmentation of liquid metal jets and LPBF powder manufacturing.

Description of the project

Direct Numerical Simulations (DNS) will be run on High-Performance Computers (HPC) to explore the fragmentation dynamics of low‑Prandtl jets, from the melting of the metal rod to the solidification of the droplets, and assess the influence of the Prandtl and Weber non‑dimensional numbers.

The following research axes will be explored:

• Characterisation of the jet flow conditions resulting from the inductive melting.The inductive melting flow will be characterised numerically by solving the two‑way coupling governing the magnetohydrodynamics (MHD) flow using finite‑element Elmer (magnetic field and induced current) and finite‑volume OpenFOAM (melting flow) open‑source software.
• Exploration of the cooling dynamics of fragmenting jet s .The heat transfer occurring during the jet fragmentation at low‑Prandtl number (Pr≈10-1), without solidification, will be studied numerically via 3D Volume‑Of‑Fluid DNS on HPC, using the open‑source solvers from the Basilisk community. A statistical analysis will be carried out to characterise the droplet population. This will be complemented by DNS of a fragmenting single droplet to observe the temporal dynamics of cooling and derive the corresponding scaling laws.
• Development of a numerical framework to model droplet solidification. Dedicated numerical solvers will be developed to run DNS of solidifying droplets in a gas phase. Solvers simulating two‑phase front solidification and three‑phase flows are available in the Basilisk community and will be taken as a starting point. Based on the solver developments, jet fragmentation DNS with solidification will be computed. The statistical analysis will be repeated and complemented with theoretical work to infer a statistical model for the size and sphericity distribution of the resulting solid particles.

Depending on the candidate’s background and specific interests, the PhD may choose to focus more on one or two of those research axes, although all three are important for the project.

Supervisors: Romain Vallon and Nathanaël Machicoane
Research fields: multiphase f luid mechanics, heat transfer, fragmentation, Direct Numerical Simulations
Possible secondments: AIA (RWTH Aachen, Germany), Unit of Processes (KTH, Sweden), Sandvik AB (Sweden)
Doctoral school: I-MEP2 (Engineering - Materials, Mechanics, Environment, Energy, Processes, Production)

The candidate should have graduated from a MSc (or equivalent) in Applied Science or Engineering with a background in one or more of the following fields:FluidDynamics,Physics, Mechanical Engineering orAppliedMathematics.Ideallywithknowledge in two‑phase flows, heat transfer and /or phase change.

Disciplinary skills, experience

Experience of scientific computing, numerical schemes, large data set analysis and HPC computing will be appreciated. Coding skills without LLMs (large language models) and knowledge of Python are mandatory. Knowledge of C++, bash programming , large data set management and code versioning is a plus. Technical English (speaking, writing and reading skills) are required.

Personal skills

This PhD position requires to be able to work in a group and to have a strong autonomy , solid critical thinking as well as good organisational and interpersonal skills. The candidate will be required to lead numerical investigations, carry out data analysis and manage large set of data rigorously, along with assimilating new knowledge quickly. They should also show perseverance and solid problem‑solving skills while scientific curiosity, to make the project moves forward, will be acknowledged and encouraged. Strong communication and reporting skills (written and oral), both on the project’s progress and the difficulties encountered, are expected. Being able to disseminate scientific results to a large audience in an educational mannerwill be appreciated.

Languages ENGLISH Level Excellent

Additional Information

Université Grenoble Alpes (UGA) is offering a 36-month full‑time work contract. In line with the European Commission rules for Marie Skłodowska‑Curie grant holders, the remuneration will consist of a gross monthly salary of 2,650 EUR. The estimated net salary to be perceived by the PhD fellow will be between 2,050 and 2,150 EUR.

Benefits include:

• Access to a high‑quality work environment, including a personal computer, scientific equipment, HPC clusters, and access to library and shared lab facilities
• Access to high‑level scientific and inter‑sectoral training through 120 hours of doctoral courses and workshops
• Opportunity for 2-month secondments at an academic institution or industrial partner during the 2nd year of the PhD
• A vast choice of networking events and activities within the PhD@Tec21 Programme and through the international network of MSCA fellows
• Access to the UGA International Student Office, to assist the PhD fellows in searching for accommodation in Grenoble and support with administrative issues including visas, health, bank accounts, etc.
• Visa fees and registration to the UGA Doctoral School are covered by PhD@Tec21
• 45 days of paid holidays
• Sick leave
• Parental leave

Eligibility criteria

• Have completed a Master’s degree or an equivalent diploma by the deadline of the programme’s call (28 February 2027)
• Do NOT already be in possession of a Doctoral degree
• Do NOT have resided or carried out their main activity (work, studies, etc.) in France for more than 12 months in the 3 years immediately preceding the deadline of the programme's call (mobility rule). Compulsory national service, short stays such as holidays, or time spent as part of a procedure for obtaining refugee status under the Geneva Convention, will not be taken into account
• Be fluent in English (at least B2 level)
• Be available for employment at the enrolment date (1 October 2027)

Selection process

This recruitment takes place within the PhD@Tec21 Programme, which isco-funded as part of the Marie Skłodowska‑Curie COFUND actions under the grant agreement #101217261. The recruitment process follows a specific selection and evaluation procedure with particular eligibility criteria, all of which are detailed in the applicant guide available on PhD@Tec21 Website .