Physical modeling of Fluid-Structure Interaction study in theframework of DRACCAR (Offshore wind mast in Fécamp)

Post-Doctorat

Profile : the good candidate in a Doctor (Post-Doc) or possibly an MSc student (Rsearch Assistant) interested in Fluid Mechanics, Computational Fluid-Dynamics (CFD), Structural Mechanics, and more generally numerical computations skills. Interest in renewable energy, offshore wind energy and energetics aspects will be a plus.

PDRA location : Laboratoire Ondes et Milieux Complexes (UMR 6294 CNRS – Université du Havre). 53, rue de Prony – BP 540 – 76058 Le Havre Cedex

Duration : 18 months

Starting date : Nov. 2024

Gross Salary : Based upon experience. Starting from ≈ €2200 to €3500 /month for an MSc and ≈ €2400 to €4400 /month for an Doctor (Post-doc)

Pre-requisite :

Python/matlab, GNU/Linux, Latex ;

Good commend of numerical method, previous experience in CFD and/or structure computations will be highly appreciated ;

Previous experience in marine hydrodynamics, experimental/numerical cross comparisons ;
A good commend of English is required.

Application :

CV and Cover Letter to the contact persons

first round of interviews between the 23rd and 27th of Sept. 2024
if the good candidate is not met, a second round of interview will take place in late Oct.
2024.

Contacts

Gaële PERRET – Associate-Prof. – Université du Havre/LOMC (UMR CNRS)
+33 (0)2 35 21 71 22 – gaele.perret@univ-lehavre.fr
Grégory PINON – Professor – Université du Havre/LOMC (UMR CNRS)
+33 (0)2 35 21 71 23 – gregory.pinon@univ-lehavre.fr

General context of the study : Project DRACCAR

Phenomena of fluid impact on structures are of major importance worldwide, and have attracted considerable research interest in recent years. This problem concerns a wide range of engineering applications, from coastal & offshore engineering to marine construction. This is particularly the case for offshore wind applications, such as bottom mounted offshore wind turbines, when regular waves or possibly extreme waves are impinging the wind turbine foundation. These impacts, whether cyclic or impulsive, generate Fluid-Structure Interactions (FSI) that may endanger the structure and possibly reduce its life-time. The structural behaviour Work-Package of DRACCAR aims at tackling these impact phenomena and related Fluid-Structure Interaction using several approaches.

Recently, France Energie Marine and 3 research establishments have created the DRACCAR project (https://www.france-energies-marines.org/projets/draccar/). University Le Havre Normandy, via its research lab. LOMC, is deeply involved in the project. Several Work-Packages exist on this project, including one that concerns the structural behaviour of the Fécamp offshore mast subjected to wave loading. The aim of the project is to better qualify the impacts loads and Fluid-Structure Interactions (FSI) that the mast is subjected to. To this end, the mast is already (or will be very soon) equipped with pressure sensors, accelerometers and stereo-video devices. In addition and in parallel, experimental tests on a similar model-scale of this offshore mast are also going to be conducted at LOMC. The third approach consists in carrying out numerical simulations of surface waves and their interaction with the Fécamp offshore mast, both at model scale and in situ. A dedicated PDRA (Post-Doc or Research Assistant) will be recruited for each of these three approaches. The combination of these three approaches is clearly a strength of the DRACCAR project as each approach will be able to feed-in its two other counterpart, owing to the complementary and advantages of each of them.

Detailed research program

This PDRA offer deals with the physical modelling related to this structural behaviour Work-Package of DRACCAR. The aim of this PDRA position is studying experimentally the response of a scaled structure to impinging waves. The design and structural dynamics of the model will be performed and analysed in accordance to the structure dynamics of the full scale structure as well as the dynamics of the impacting waves. The person recruited will have to be able to show a certain degree of autonomy in choosing the appropriate design for the model and in performing the experiments. She/he should also be able to make suggestions. This research period will take place within the LOMC hydrodynamics team at the Université Le Havre Normandie/CNRS. A knowledge of reading, writing and speaking English is strongly recommended for the successful completion of this work.

Different steps of the work

1. Bibliography on impact wave loads characterisation.

2. Different models will be tested :
— models for which the natural modes are scaled from those of the full scale structure
— models with a scaled geometry.
The design and structural dynamics of each model will have to be performed.

3. Set-up of the models and the instrumentation : pressure sensors, loads sensors, vibrometers.

4. Definition of the hydrodynamic forcing : regular waves conditions and impacting waves.

5. Set-up and run of the experiments.

6. Analysis of results for impulsive impacts in terms of pressure, deformation, displacement and overall force exerted ;

7. Writing scientific publications and participation to an international conference.