Wake characteristics of pumping mode airborne wind energy systems

Abstract

Airborne wind energy is an emerging technology that aims at harvesting wind power at high altitudes. In the present work, we propose a framework combining optimal control and large-eddy simulation to investigate the wake characteristics of large-scale airborne wind energy systems. We consider systems operating in pumping mode which alternate between power-generating and -consuming phases. We investigate the downstream wake development in non-turbulent and turbulent sheared inflow conditions. The optimal system operation leads to a non-uniform radial wake development and results show that the maximal wake velocity deficit for the current system is half the deficit predicted by Betz limit for a conventional wind turbine.