The application of conventional wind turbines on board a vessel creates a number of new challenges for turbine control systems. Thrust force is used in marine applications as an additional control variable for propulsion of the vessel. Variability of the wind speed and wind direction, together with the yaw rate and range constraints, impose strong requirements on the turbine control system. A n...

The characteristics of carbon fibre reinforced plastics allow a very broad range of uses. Drilling is often necessary to assemble different components, but this can lead to various forms of damage, such as delamination which is the most severe. However, a reduced thrust force can decrease the risk of delamination. In this work, two variables of the drilling process were compared: tool material ...

We investigate the suppression of the vibrations of a wind turbine tower using colocated feedback to achieve strong stability. We decompose the system into one model describing the vibrations in the plane of the turbine axis and another model in the plane of the turbine blades. In the plane of the turbine axis, we obtain a non-uniform Spacecraft Control Laboratory Experiment (SCOLE) model with ...

An experimental study was conducted to investigate on the effects of the relative rotation directions of two tandwm wind turbines on the power production performance and flow characteristics in the wakes of two wind turbines in tandem. The experimental study was performed in a large-scale Aerodynamics/tmospheric Boundary Layer (AABL) Wind Tunnel located at the Aerospace Engineering Department o...

Modern designs for straight-bladed vertical axis wind turbines (VAWTs)feature smaller individual footprints than conventional horizontal axis wind turbines (HAWTs), allowing closer spacing of turbines and potentially greater power extraction for the same wind farm footprint. However, the wakes of upstream turbines could persist far enough to affect the performance of closely-spaced downstream t...

Unlike conventional hydro and tidal barrage installations, water current turbines in open flow can generate power from flowing water with almost zero environmental impact, over a much wider range of sites than those available for conventional tidal power generation. Recent developments in current turbine design are reviewed and some potential advantages of ducted or “diffuser-augmented” current...

Utility system operators and engineers want a better understanding of the impacts of large wind farms on grid stability before they are interconnected to the grid. Utilities need wind electrical models and methods of analysis that will help them analyze potential problems of grid stability. Without the necessary tools and knowledge of the behavior of large wind farms, utilities are reluctant to...

pits, quarries, and on construction sites. The prediction of the penetration rate of drilling machines is very important for cost estimation and planning of rock excavation projects. Many researchers have investigated percussive drilling theoretically or experimentally and correlated the penetration rate with various rock properties. Protodyakonov (1962) developed drop tests and described the c...

Every year the number of installed wind power plants in the world increases. The horizontal axis wind turbine is the most common type of turbine but there exist other types. Here, three different wind turbines are considered; the horizontal axis wind turbine and two different concepts of vertical axis wind turbines; the Darrieus turbine and the H-rotor. This paper aims at making a comparative s...

An impulse bio turbine with circular inlet/outlet area which can be integrated into small devices, is presented. The system was designed using a scaled impulse macro turbine model, which was modified in size and shape to guarantee integration in implantable bio medical devices and physiological circulatory system. The simplicity in the design reduces cost and makes it very suitable for developi...