Virtual Wind Environment and Flight Simulator for AWE Systems

The ESR will perform large eddy simulations of AWE systems in the atmospheric boundary layer and investigate the effects of turbulence, wind shear and stratification on the systems’ performance.

Project

Airborne Wind Energy (AWE) systems operate in the Atmospheric Boundary Layer (ABL), the lower region of the atmosphere, and are subject to turbulence, wind shear and stratification. Stable, neutral, and unstable stratification lead to different velocity profiles and turbulent-flow structures. In addition, Coriolis forces induce different wind directions above the ABL and at ground level, a phenomenon known as Ekman spiral. The ABL is also often capped by a strongly stable temperature inversion layer. Above land, this layer is usually situated around 1 km, while at sea, it may come down to a height of a few 100 meters, well into the region where AWE systems operate. Thus the project’s objective is to quantify and enhance the power extraction of AWE systems in the particular context of atmospheric flows by taking all these different flow phenomena into account.

Computational fluid dynamics and high performance computing methods are used to investigate the interaction between AWE systems and the atmospheric boundary layer. The current PhD research focuses on the large eddy simulations of AWE systems for different realistic turbulent flow conditions. To that end, an AWE model is implemented in the simulation code currently developed by the TFSO group at KU Leuven, the SP-Wind code. Also, an efficient interface is developed that allows coupling any kite-control model to SP-Wind, constituting a virtual testing environment. The PhD research further focuses on numerical optimization techniques for single AWE systems as well as arrays and farms of AWE systems. Using optimal control and adjoint-based optimization methods the ESR strives after optimal flight trajectories and possibly optimal reaction to upstream flow structures. Finally, also the interaction of the wakes induced by AWE systems are investigated.

PhD Researcher

Thomas Haas is AWESCO fellow and PhD candidate at KU Leuven, Belgium, since 01. September, 2015. Originally from France, he received his German-French Bachelor’s degree from the Université de Strasbourg, France (B.Sc in Applied Physics) and the Hochschule Offenburg, Germany (B.Eng in Mechanical Engineering) in 2011. He finished his degree with a Bachelor's thesis on the numerical investigation of Coriolis flowmeters at Endress+Hauser Flowtec AG in Switzerland. In 2014 Thomas Haas successfully completed his Master’s degree in Engineering Sciences with specialization in Fluid Mechanics and Thermodynamics from Technische Universität Berlin, Germany. The topic of his Master's thesis is the numerical investigation and dynamic mode decomposition of a pulsed impinging jet. Thomas Haas’ main research interests are Computational Fluid Dynamics and power generation. Especially the field of renewable energies, and in particular airborne wind energy, as well as innovative energy startups receive his consideration.

Supervisor

Prof. dr. ir. Johan Meyers is professor at KU Leuven, Belgium, and leads the research group on Turbulent Flow Simulation and Optimization. The research group focuses on simulation, optimization, and optimal control of turbulent flows. The group also develops efficient supercomputing simulation tool for applications in energy engineering.