Topic
Wind shear
About: Wind shear is a research topic. Over the lifetime, 8023 publications have been published within this topic receiving 185373 citations.
Papers published on a yearly basis
Papers
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TL;DR: In this article, upper air soundings that occurred within 2 h and 167 km of derechos were collected and analyzed to document atmospheric stability and wind shear conditions associated with long-lived convective windstorms.
Abstract: Observed upper air soundings that occurred within 2 h and 167 km of derechos were collected and analyzed to document atmospheric stability and wind shear conditions associated with long-lived convective windstorms. Sixty-seven derechos, accompanied by 113 proximity soundings, were identified during the years 1983–93. Owing to the large variability of the synoptic-scale environments associated with derechos, each derecho was further divided into categories based on the strength of synoptic-scale forcing associated with each event. Derechos are shown to develop and persist in a wide range of shear and instability conditions. Although this range of shear and instability narrows when derechos are grouped by synoptic-scale forcing strength, considerable variation of values remains, primarily with the shear. These results suggest that ambient shear and instability values alone are not sufficient to distinguish derecho environments from those associated with nonsevere mesoscale convective system (MCS) e...
205 citations
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TL;DR: In this article, a case study conducted along the Gulf and Atlantic Coasts of the United States is presented and the results of the simulation to specific oceanic regions are discussed and the application of the model to specific regions is discussed.
204 citations
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TL;DR: In this paper, a systematic relationship between ground roughness and wind velocities near ground and its rate of increase with height was found. But the relationship was not studied for the British Isles.
Abstract: Use of term extreme wind velocity averaged over a mile a minute as basic design wind velocity; systematic relationship between ground roughness and wind velocities near ground and its rate of increase with height; estimates of ratio of surface velocity to gradient velocity; extreme-value data for British Isles.
204 citations
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TL;DR: In this paper, the authors studied the wake deflection and morphology of a wind turbine operating in yaw conditions using wind tunnel experiments and uniform inflow and found that the wake shape and curvature exhibited significant spanwise asymmetry, and the wake curling observed in the experiments is also reproduced qualitatively in Large Eddy Simulations using both actuator disk and actuator line models.
Abstract: Reducing wake losses in wind farms by deflecting the wakes through turbine yawing has been shown to be a feasible wind farm controls approach. Nonetheless, the effectiveness of yawing depends not only on the degree of wake deflection but also on the resulting shape of the wake. In this work, the deflection and morphology of wakes behind a porous disk model of a wind turbine operating in yawed conditions are studied using wind tunnel experiments and uniform inflow. First, by measuring velocity distributions at various downstream positions and comparing with prior studies, we confirm that the non-rotating porous disk wind turbine model in yaw generates realistic wake deflections. Second, we characterize the wake shape and make observations of what is termed as curled wake, displaying significant spanwise asymmetry. The wake curling observed in the experiments is also reproduced qualitatively in Large Eddy Simulations using both actuator disk and actuator line models. Results suggest that when a wind turbine is yawed for the benefit of downstream turbines, the curled shape of the wake and its asymmetry must be taken into account since it affects how much of it intersects the downstream turbines.
201 citations
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TL;DR: In this article, a clustering algorithm based neuro-fuzzy method was proposed to find wind speed profile up to height of 100 m based on knowledge of wind speed at heights 10, 20, 30, 40 m.
201 citations