The most common controller in wind turbine is the blade pitch angle control in order to get the desired power. Controlling the pitch angle in wind turbines has a direct impact on the dynamic performance of the machine and fluct­uat­io­ns in the power systems. Due to constant changes in wind speed, the wind turbines are of nonlinear and multivariate system. The design of a controller that can ad...

The theory, methods, and applications of the videogrammetric model deformation (VMD) measurement technique used at NASA for wind tunnel testing are presented. The VMD technique, based on non-topographic photogrammetry, can determine static and dynamic aeroelastic deformation and attitude of a wind-tunnel model. Hardware of the system includes a video-rate CCD camera, a computer with an image ac...

The wind speed gauge in a tunnel plays an important role the airflow simulation process so that it is similar to actual conditions as desired. Wind measurement mostly use manometer with special fluid (red fluid) and resulting data form of analog data. red unavailable Indonesia its price quite expensive becomes challenge for tunnels still manometer. Therefore, necessary make new instrument measu...

Echolocating bats face the challenge of coordinating flight kinematics with the production of echolocation signals used to guide navigation. Previous studies of bat flight have focused on kinematics of fruit and nectar-feeding bats, often in wind tunnels with limited maneuvering, and without analysis of echolocation behavior. In this study, we engaged insectivorous big brown bats in a task requ...

abstract many people know the important effects of caspian sea winds and storms on the economy of three provinces of iran including gilan, mazandaran, and golestan that they form one exclusive and extent area which have moderate and humid climate. this paper used a synoptic climatologically approach, which combine a number of atmospheric factors. using daily and monthly winds data including the...

Nowadays, propagation of wind turbines make challenges to supply safe power to the grid. Because of wind speed changes, supervisors are concerned to wind turbines, be able to produce appropriate electric power during the wind speed changes. As a matter of fact, investors are mostly like to invest on offshore wind farms, because of their more stable and continuous wind speed rather than onshore ...

metric (mapping evapotranspiration at high resolution with internalized calibration) is known as an appropriate surface energy balance model for the estimation of the spatial distribution of evapotranspiration (et) in semi-arid regions. based on lysimeter measurements, metric has shown et estimates of 10% on a sub-field scale on a daily basis. there is a need to identify how the model is sensit...

A large body of work has shown that year-to-year variations in North African dust emission are inversely proportional to previous-year monsoon rainfall in the Sahel, implying that African dust emission is highly sensitive to vegetation changes in this narrow transitional zone. However, such a theory is not supported by field observations or modeling studies, as both suggest that interannual var...