Unsteady aerodynamic simulations of a multi-megawatt airborne wind energy reference system using computational fluid dynamics

Abstract

Airborne wind energy (AWE) is an emerging technology for the conversion of wind energy into electricity by flying crosswind patterns with a tethered aircraft. Having a proper understanding of the unsteady interaction of the air with the highly dynamic system during operation is key to developing viable AWE systems. High fidelity simulation tools are needed to correctly predict these interactions, which will provide insights into the design and operation of advanced and efficient AWE systems. The research goal of this contribution is to predict the time-varying aerodynamic forces acting on a reference system, which will be achieved using high-fidelity modelling. This work contains a feasibility study that uses the Chimera overset technique to simulate aerodynamic behaviour over the complete flight trajectory. The motion of the AWE system is included by overlaying the moving body-fitted mesh attached to the AWE aircraft over the background mesh. The Chimera overset technique connects both meshes, interpolating the solution at the overset boundary. This technique has been proven to be a robust approach to simulate the motion of an AWE system in computational fluid dynamics (CFD) simulations.