Post-Doc position in thermal hydraulics at IRSN

A post-doctoral position has been opened at IRSN to realize experimental campaigns for GO-VIKING WP4.

GO-VIKING is a European Commission funded project that kicked off in June 2022. (Project website is under construction)


The experimental device, on which the work will focus, is called TREFLE and allows to realize two phase air-water cross-flows inside a tube bundle, and to study the fluid-structure interaction.


The post-doc is meant to start at the beginning of 2023, but any starting date from now can be possible.

The full description can be found HERE

Subject: thermal-hydraulics
Keywords: two-phase flows, fluid-structure interactions, experimental measurements, steam generators
Place: Cadarache – France (13)
Length: 18 months
Availability date: 01 February 2023 (different starting date – sooner or later – possible, depending on the candidate availability)
Supervisors: Daniele VIVALDI and Guillaume BRILLANT


Fluid-structure interactions (FSI) are a concern in nuclear power plants. One main example is the fluid-induced vibrations (FIV) of the steam generator (SG) tube bundle. The external steam-water two-phase flow crossing the tubes induces FSI mechanisms that, if not mastered, can lead to high amplitudes of vibration, which can result in a SG tube rupture accident.

The Gathering expertise On Vibration ImpaKt In Nuclear power Generation (GO-VIKING) European project, starting in 2022, aims at increasing the expertise and at improving the tools and skills of the European nuclear stakeholders for the analysis of complex FIV phenomena, in order to maintain and enhance nuclear plant safety. The scope of work package (WP) 4 of GO-VIKING is the generation of high-quality experimental data for FIV in multiphase flows in fuel assemblies and SGs, with the aim of providing a deeper understanding of these complex phenomena and using this data to improve medium-resolution models for two-phase FIV.

In the frame of WP4 of GO-VIKING, IRSN – Institut de Radioprotection et de Sûreté Nucléaire – proposes the generation of two-phase experimental data inside a SG relevant tube bundle configuration. To achieve this, IRSN developed the experimental device TREFLE [1], located at IRSN in Cadarache. TREFLE allows to realize air-water cross-flows inside a square-pitch 5×5 straight tube bundle. The device is highly instrumented for two-phase flow measurements: optical probes to measure local void fractions and velocities, Wire Mesh Sensor to measure 2D void fraction distributions and high-speed camera to study the flow dynamics. Besides, TREFLE allows to measure the vibration response of the central tube of the tube bundle thanks to accelerometers. A sketch of TREFLE is presented in Fig. 1. Fig. 2 shows some pictures of the two-phase flow generated and observed inside TREFLE.
The experimental data generated with TREFLE will be shared with all GO-VIKING participants, and will be used as reference data for numerical simulation result validation: the experimental tests will be simulated through different multiphase CFD tools by some participants of WP4 (Nuclear Research and consultancy Group (NRG), Teknologian tutkimuskeskus VTT Oy (VTT), Commissariat à l’énergie atomique et aux énergies alternatives (CEA), EDF Energy R&D UK Centre Limited (EDF-E)).