Maximilian Ranneberg

EnerKíte GmbH

Online optimization of annular-phased-array hyperthermia (HT) is based on planning tools and magnetic resonance (MR) thermometry. Until now, the method has been validated in phantoms. Further developments and extensions are required for clinical purposes. In particular, the problem of deducing the electric field distribution inside the patient from...

Besides other aspects such as safety, capital expenditures, lifetime and maintenance of a wind energy converter, the power curve is the defining performance characteristic in order to derive its economic viability. Power curves for horizontal axis wind turbines have been studied, validated and optimized for decades. This study tackles the power cur...

A fast computational method of analysing the effect of Gurney flaps is presented. A viscous-inviscid interaction method is employed, which couples the integral boundary layer equations with a panel method for fast viscous analysis of airfoils. The Gurney flap is added via the mass defect at a single panel node. This leads to very fast results, in t...

Viscous–inviscid interaction is the fastest method in computational fluid dynamics available for airfoil design and analysis that is able to capture viscous effects on the flow. Despite advances in (Reynolds-averaged) Navier–Stokes equations solvers and models, it is arguably the first choice for preliminary and even detailed design. A new method o...

Airborne wind energy (AWE) is the conversion of wind energy into electricity using tethered flying devices. Replacing towered wind turbines by lightweight tensile structure not only reduces the material effort and thus cost of energy, but also provides access to an energy potential that has not been used so far, wind at higher altitudes. In this wo...

In this work we explore the initial design space for composite kites, focusing on the configuration of the bridle line system and its effect on the aeroelastic behaviour of the wing. The computational model utilises a 2D cross sectional model in conjunction with a 1D beam model (2+1D structural model) that captures the complex composite coupling ef...

In this paper, we present an aero‐structural model of a tethered swept wing for airborne wind energy generation. The carbon composite wing has neither fuselage nor actuated aerodynamic control surfaces and is controlled entirely from the ground using three separate tethers. The computational model is efficient enough to be used for weight optimisat...

Presenting the paper study for an prospective 100 kW Airborne Wind Energy Solution (EnerKite) with high capacity factor, achieving 16 ct/kWh and 88% diesel savings with an cost optimal hybrid off-grid system at specific demand load profile. 100% Renewables with EnerKíte results in about 15 - 20% higher cost of electricity oat 18.4 ct/kWh compared...

A vortex-lattice method for wing aerodynamics that uses nonlinear airfoil data is presented. Two applications of this procedure are presented: Direct Design of a Flying Wing and Inverse Identification from wind tunnel measurements with low-aspect ratio wings. A Newton method is employed, which not only allows very fast solutions to the nonlinear eq...

EnerKite GmbH designed, built and demonstrated a three line AWE system. This article presents history of the enterprise and the decisions involved. The built ground station is described in detail, and flight data obtained during the course of a year in development is presented.KeywordsWind SpeedTurbulence IntensityController DevelopmentUltrasonic A...

An unscented Kalman filter with joint state and parameter estimation is proposed for aerodynamics, states and wind conditions for airborne wind energy converters. The proposed estimator relies on different measurement setups. Due to the strict economic constraints of wind energy converters, the sensor setups are chosen with minimal cost and reliabi...