Stage HQ- Simulation CFD de l'action des vents traversiers sur un train (H/F/NB)

Objective:

Crosswind action on a train poses a risk of vehicle overturning or derailment. To assess if a new train design fulfills the safety requirements, computational fluid dynamics (CFD) is commonly used in combination with wind tunnel testing. The current methodology used for the simulations within the AeroX network is based on RANS turbulence models. It is shown that for yaw angles up to 45 degrees, aerodynamic forces predicted by RANS models are consistent with experimental data. At larger yaw angles, flow structure becomes complicated, separation lines are no longer defined by geometry, and significant discrepancies appear between RANS based simulations and experimental results.

The objective of this internship is to explore other turbulence models available in STAR-CCM+ software (LES, DES), assess their level of correlation with experimental data and ultimately to improve to the current CFD methodology for crosswind.

Software:  STAR-CCM+

Tasks:

1. Getting familiar with the software and the current way of working/methodology.
2. Exploring other CFD models (e.g: LES, DES):
   1. Setting up the simulations with the appropriate parameters,
   2. Running the simulations,
   3. Comparing results to available experimental data.
3. Identifying the best simulation setup and including it in the current automated process. 
4. Preparing a technical report.

Deliverables:

1. Technical report defining the new methodology and comparing results obtained with the selected new model to the existing RANS and experimental results.
2. New methodology implemented within the automated process currently in place.

Duration: 6 months

Period: 02/2025-07/2025

Pre-requisite: Computational fluid dynamics background. Experience with at least one commercial CFD software. Programming knowledge (java) is a plus.

Keywords:

• CFD, STAR-CCM+, Java
• Wind tunnel correlation
• Crosswind stability

Languages: English & French