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 ...

Yttria-stabilized zirconia (YSZ) is of interest to the aerospace community, notably for its application as a thermal barrier coating for turbine engine components. In such an application, diffusion of both oxygen ions and cations is of concern. Oxygen diffusion can lead to deterioration of a coated part, and often necessitates an environmental barrier coating. Cation diffusion in YSZ is much sl...

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...

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...

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...

Wind turbines are known to produce shadow flicker by interruption of sunlight by the turbine blades. Known parameters of the seizure provoking effect of flicker, i.e., contrast, frequency, mark-space ratio, retinal area stimulated and percentage of visual cortex involved were applied to wind turbine features. The proportion of patients affected by viewing wind turbines expressed as distance in ...

Many challenges exist for the efficient and safe operation of wind turbines due to the difficulty in creating accurate models of their dynamic characteristics and the turbulent conditions in which they operate. A promising new area of wind turbine research is the application of adaptive control techniques, which are well suited to problems where the plant model is not well known and the plant o...

Typical wind turbine systems are sufficiently large so as to require extensive physical space for their installation and operation. These requirements preclude the use of turbines in crowded, urban environments. On the other hand, smaller turbine systems may find practical application as rooftop units, installed atop tall buildings. Such rooftop units must be much smaller than their ground-base...