Description of the thesis topic

The objective of the PhD study will be to characterise new unsteady aerodynamic loads encountered by forthcoming 25+MW wind turbine rotors at the airfoil scale and to identify control strategies. Large scale turbines 25+MW will have their rotor spanning over a much larger size than today's turbines, within 3D dynamic inflow conditions from the atmospheric boundary layer. This is generally perceived at the blade scale as additional local unsteadiness and thus additional aerodynamic loads. Also, by interacting with longer and slender blades, loads will be amplified which may lead to structural failure. Knowing that the unsteady aerodynamic load models are used as inputs of standard design tools (Blade Element Momentum Theory: BEMT), this of major importance to upgrade it for large scale rotors 25+MW. A first part of the PhD work will be to provide a detailed experimental characterization of the unsteady aerodynamic loads under new dynamic inflow conditions. A spatio-temporal description of the flow will be investigated in correlation with unsteady wall pressure measurements. The database will be used : 1) as unsteady aerodynamic load inputs for Blade Element Momentum Theory simulations; 2) to formulate new 2D airfoil unsteady aerodynamic models for large rotors in collaboration with TU-Deflt (partner of the NEXTgenT project); and 3) to investigate sensor locations, number, and types for future active control objectives.

The last year of the thesis, the candidate will work 3 month at VALEMO, on an available database from a wind turbine farm with one turbine has its blades equiped with aerodynamic sensors. The objective will be to investigate their potentiallity for blade monitoring.

Work Context

This PhD is a part of the NEXTgenT (NEXT generation of over 25MW offshore wind Turbine rotor design) MSCA Doctoral Networks.

The overall objective of the European NEXTgenT training network is to educate a new generation of researchers capable of converting their new knowledge of atmospheric science and wind turbine technologies into the development of the next generation of 25+MW offshore wind turbine rotor systems.

By being part of a MSCA Doctoral Network, you will have the opportunity to meet regularly and work closely with a group of your fellow PhD candidates, a distributed team of experts, both from academia and wind industry located all across Europe. You will also have the opportunity for two secondments (3 months each) in one industrial partner and one academic partner in the the NEXTgenT Doctoral Network.

About LHEEA-CNRS
The PhD student work will take place at the ”Laboratoire d'Hydrodynamique, d'Energétique et d'Environnement Atmosphérique” (LHEEA) at École Centrale de Nantes (ECN). LHEEA is a JRU (Joint Research Unit – UMR 6598)– UMR 6598) whose legal representatives are ECN and Centre National de Recherche Scientifique (CNRS).

LHEEA has a staff of about one hundred, including about 30 PhD students. The lab has an internationally recognized expertise on free surface, atmospheric flows and aerodynamics, which is carried both through numerical simulation and experimental work. Wind energy is one of the main areas of interest of the lab, focusing on interactions between wind turbines and atmospheric flows, wind turbines rotor and blade aerodynamics, blade flow control and monitoring.

CNRS, operating under the French Ministry of research, is the largest French research organization, and the larges in Europe in terms of publications. With 32000 staff and 1000 laboratories spread throughout the country, the CNRS carries out research in all scientific fields of knowledge. Its major objectives are to improve knowledge, promote interdisciplinarity, ensure economic and technological development and solve complex societal needs. In 2017, it was awarded "HR Excellence in Research (HRS4R)".

With about 1100 undergraduate and 250 graduate students, ECN is one of the top engineering schools in France. Ecole Centrale de Nantes is allowed to award PhD degrees and consequently, researchers recruited by the beneficiary LHEEA-CNRS will be registered at ECN as PhD students. .

The candidate will thus get the chance to work in one of the best research institute in Europe, CNRS, and within the best engineering schools in France, École Centrale de Nantes (ECN).

Additional Information

Requirements

The candidate should have an MSc degree in wind energy from a well-established university or an MSc degree in related engineering disciplines such as mechanical engineering, fluid dynamics, turbulence, applied physics, or applied mathematics with proven experience (courses, projects, and work experience) in the field of aerodynamics or wind engineering or turbulence.

A combination of good mathematical skills in fluid dynamics and a strong interest on experimental aerodynamics/aeroelasticity and turbulent flows are required. Experience with experimental techniques in aerodynamics, fluid dynamics or turbulence is preferred.

Eligibility criteria
Fulfilment of eligibility criteria is dictated by the European Commission under the Horizon MSCA Doctoral Networks Programme. We welcome applications from PhD candidates from any country fulfilling the following mobility criteria:
Eligible candidates must not have resided or carried out their main activity (work, studies, etc.) in the country of their first host institution for more than 12 months in the 3 years immediately before their recruitment by the host institution (i.e., the starting date indicated in the employment contract/equivalent direct contract).

Eligible candidates must have a master's degree relevant to the chosen position or its equivalent that would entitle them to a doctorate, awarded before the start of the positions.

Due to the international context of the PhD, it requires English proficiency at a certain level to ensure that the candidate is able to communicate and interact well, participate in English-taught Doctoral Education courses, and write scientific articles and a final thesis.