Aerodynamic advances in vertical-axis wind turbines

As wind farms tend to move towards deeper waters with better wind resources, the classical top-heavy horizontal-axis wind turbines (HAWTs) become particularly challenging. This raises the question whether other concepts could be more suitable and compatible with the deep-sea floating conditions. Hence, the interest in vertical-axis wind turbines...

A new dynamic inflow model for vertical-axis wind turbines

This paper presents a new dynamic inflow model for vertical-axis wind turbines (VAWTs). The model uses the principle of Duhamel's integral. The indicial function of the inflow- and crossflow-induction required to apply Duhamel's integral is represented by an exponential function depending on the thrust coefficient and the azimuthal position....

An extended actuator cylinder model: Actuator-in-actuator cylinder (AC-squared) model

In this paper, the actuator-in-actuator cylinder (AC-squared) model is presented. This model is an extension of the original actuator cylinder model of Madsen and is capable of modelling the effect of a two concentric actuation surfaces in 2D. The induced velocity at every point in the 2D field is affected by the force field acting on the two...

Investigating the potential of load and power control on a VAWT through active pitch control in 2D

Within this thesis influence of thrust vectoring for VAWTs, controlling the magnitude and direction of the thrust vector with respect to the freestream, is investigated through active pitch actuation. The H-type Darrieus VAWT is modelled in 2D through the actuator cylinder model with the Mod-Lin correction included. The evaluations are performed...

A CFD study of the Actuator Cylinder model

Simulation and Optimisation of unsteady aerodynamic performance of a 2D VAWT rotor: With emphasis on airfoil design

Airfoil design plays an important role in improving the performance of Vertical Axis Wind Turbines(VAWTs). The aim of this thesis is to arrive at optimal airfoil geometries to enhance the performance of VAWTs and analyse the performance of these optimal airfoils under steady and unsteady operation conditions of the rotor. The airfoil design is...

Double actuator cylinder (AC) model of a tandem vertical axis wind turbine (VAWT) counter-rotating rotor concept operating in different wind conditions

The aim of this thesis is to evaluate the influence between the two counter-rotating VAWT rotors with the Double Actuator Cylinder (DAC) model which will be validated against the panel code. The DAC model is developed from the original Actuator Cylinder (AC) model which includes the Modified-Linear (Mod-Lin) correction. The original AC model for...