This paper investigates the relationships between friction velocity, 10m drag coefficient, and 10m wind speed using data collected at two offshore observation towers (one over the sea and the other on an island) from seven typhoon episodes in the South China Sea from 2008 to 2014. The two towers were placed in areas with different water depths along a shore-normal line. The depth of water at th...

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 ...

Assessment of profitability, based on the accurate measurement of the frequency distribution of wind speed over a certain period and the prediction of power generation under measured conditions, is normally a centrally important consideration for the installation of wind turbines. The frequency distribution of wind speed is evaluated, in general, using the Weibull distribution. In order to pred...

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...

The problem of control associated wind energy conversion systems using horizontal-axis fixed-pitch variable speed low-power, working in the partial load region, consisting in the energy conversion maximization, is approached here under the assumption that the wind turbine model and its parameters are poorly known. Intelligent gradient detection method by using Maximum Power Point Tracking (MPPT...

The first part is the statistical structure of wind speed, i.e. the methods for determination of Weibull-distribution’s parameters, fitting of frequency distribution of daily and monthly mean wind speeds with the Weibull-distribution, estimation of frequency distributions of daily and monthly mean wind speeds with the Weibull-distribution at different heights. The second part includes the stati...

With the increase of wind power as a renewable energy source in many countries, wind speed forecasting has become more and more important to the planning of wind speed plants, the scheduling of dispatchable generation and tariffs in the day-ahead electricity market, and the operation of power systems. However, the uncertainty of wind speed makes troubles in them. For this reason, a wind speed f...

Wind erosion is considered as one of the main processes of land degradation in different parts of the world. Among the most effective ways to control wind erosion is to cover land surface with natural vegetation area. In this study, 3 replica soil samples were collected, at a depth of 0-3 cm, from various land uses in Dehloran, Ilam Province, Iran. Physical and chemical characteristics of soil ...