نتایج جستجو برای: sudden increase in wind speed

تعداد نتایج: 17055085  

2007
Y. Quilfen C. Prigent B. Chapron A. A. Mouche N. Houti

The physics of remote sensing sea surface measurements is still poorly understood under severe weather conditions. Wind vector algorithms are usually developed for non-precipitating atmospheres and for wind speeds less than 20 m/s. In this study, we analyze observations from the QuikSCAT Kuband scatterometer collocated with the WindSat full polarimetric microwave radiometer to estimate the pote...

2015
Shuting Wan Lifeng Cheng Xiaoling Sheng Chi-Ming Lai

Natural wind is stochastic, being characterized by its speed and direction which change randomly and frequently. Because of the certain lag in control systems and the yaw body itself, wind turbines cannot be accurately aligned toward the wind direction when the wind speed and wind direction change frequently. Thus, wind turbines often suffer from a series of engineering issues during operation,...

2011
O. M. Salim M. A. Zohdy

Wind energy contribution as a source of energy in electric utility systems around the world is on the increase. One of the major challenges of wind energy generation is its natural intermittency; unpredictability, and uncertainty. In this paper, two and three dimensional visualization profiles were presented for the power coefficient. Further, two and three dimensional profiles for the turbine ...

2017
Lup Wai Chew Negin Nazarian Leslie Norford

Dense urban areas restrict air movement, causing airflow in urban street canyons to be much lower than the flow above buildings. Boosting near-ground wind speed can enhance thermal comfort in warm climates by increasing skin convective heat transfer. We explored the potential of a wind catcher to direct atmospheric wind into urban street canyons. We arranged scaled-down models of buildings with...

Introduction: Wind erosion is a phenomenon that causes severe environmental changes in arid and semi-arid climates. As surface soil texture is very effective in soil erodibility, identifying soil erodibility index is important and efficient. Mismanagement greatly contributes to the development of wind erosion. The velocity that makes the first particles of soil move from the surface is called t...

2012
Rishabh Dev Shukla R. K. Tripathi

Nowadays research focus is towards the Variable speed power generation in instead fixed speed power generation in wind energy conversion system. With variable speed, there will be 20-30% increase in the energy capture compared to the fixed-speed operation. For Variable speed wind energy conversion system the maximum power point tracking (MPPT) is a very important requirement in order to maximiz...

2015
Weijie Wang Amato T. Evan Cyrille Flamant Christophe Lavaysse

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...

Abstract. Wind as a resource of renewable energy has obtained an important share of the energy market already. Therefore simulation and prediction of wind speeds is essential for both, for engineers and energy traders. In this paper we analyze the surface wind speed data from three prototypic locations: coastal region (Rotterdam), undulating forest landscape few 100 m above sea level(Kassel), ...

ژورنال: علوم آب و خاک 2019

The purpose of this study was to model the relationship between the frequency of dust storms and climatic variables in desert areas of Iran. For this purpose, climatic data of temperature (maximum and minimum), rainfall, wind speed (maximum and minimum), and their relationship with the number of days with dust recorded in 25 meteorological stations (statistical period since their inception unti...

Nowadays, optimal placement of wind turbines in a wind farm is one of the major concerns of the wind farm designers. This paper concentrates on the optimal placement of wind turbines in a wind farm. The optimal placement of wind turbines has been carried out to maximize the output energy and minimize the investment cost of cable, road and wind turbines. For this purpose, Firstly, it should be d...

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