scholarly journals Aircraft Runway Acceleration in the Presence of Severe Wind Gusts

2016 ◽  
pp. 147-158
Author(s):  
Nikolai Botkin ◽  
Varvara Turova
Keyword(s):  
Wind Gusts

scholarly journals Improvement Dependability of Offshore Horizontal-Axis Wind Turbines by Applying New Mathematical Methods for Calculation the Excess Speed in Case of Wind Gusts

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3085
Author(s):  
Konstantin Osintsev ◽  
Seregei Aliukov ◽  
Alexander Shishkov
Keyword(s):  
Computer Simulation ◽  
Wind Turbines ◽  
Experimental Studies ◽  
Offshore Wind ◽  
Approximation Schemes ◽  
Calculation Error ◽  
Strong Wind ◽  
Mathematical Methods ◽  
Wind Gusts ◽  
Gas Dynamic

The problem of increasing the reliability of wind turbines exists in the development of new offshore oil and natural gas fields. Reducing emergency situations is necessary due to the autonomous operation of drilling rigs and bulk seaports in the subarctic and Arctic climate. The relevance of the topic is linked with the development of a methodology for theoretical and practical studies of gas dynamics when gas flows in a pipe, based on a mathematical model using new mathematical methods for calculation of excess speeds in case of wind gusts. Problems in the operation of offshore wind turbines arise with storm gusts of wind, which is comparable to the wave movement of the gas flow. Thus, the scientific problem of increasing the reliability of wind turbines in conditions of strong wind gusts is solved. The authors indicate a gross error in the calculations when approximating through the use of the Fourier series. The obtained results will allow us to solve one of the essential problems of modeling at this stage of its development, namely: to reduce the calculation time and the adequacy of the model built for similar installations and devices. Experimental studies of gas-dynamic flows are carried out on the example of a physical model of a wind turbine. In addition, a computer simulation of the gas-dynamic flow process was carried out. The use of new approximation schemes in processing the results of experiments and computer simulation can reduce the calculation error by 1.2 percent.

scholarly journals A Robust Control for an Aerial Robot Quadrotor under Wind Gusts

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Li Ding ◽  
Zhenwei Wang
Keyword(s):  
Parameter Tuning ◽  
Stability Control ◽  
Euler Method ◽  
Nonlinear Dynamical ◽  
Active Disturbance Rejection ◽  
Wind Gusts ◽  
Disturbance Rejection Control ◽  
Control Scheme ◽  
Aerial Robot ◽  
Linear Extended State Observer

A robust flight controller based on linear active disturbance rejection control (LADRC) is proposed for stability control of an aerial robot quadrotor under wind gusts. The nonlinear dynamical model of the quadrotor, considering the wind disturbance, is firstly established through Newton-Euler method. Subsequently, a robust LADRC technique is proposed to design the controllers for the inner loop and outer loop of the aircraft. In this control scheme, the linear extended state observer (LESO) serves as a compensator which can effectively reject the wind gusts. Then, a method of parameter tuning is introduced to obtain the optimized control performance. Finally, the effectiveness and advantages of the proposed controller are demonstrated through series of simulation case.

The Importance of Wind Gusts in Distributing Fungal Spores Among Crop Foliage

EPPO Bulletin ◽  
1983 ◽  
Vol 13 (2) ◽  
pp. 133-137 ◽  
Author(s):  
H.A. McCARTNEY ◽  
A. BAINBRIDGE ◽  
D.E. AYLOR
Keyword(s):  
Fungal Spores ◽  
Wind Gusts

Untersuchungen zur Ableitung von Windböen aus Doppler-Lidar-Messungen

2021 ◽  
Author(s):  
Carola Detring ◽  
Eileen Päschke ◽  
Julian Steinheuer ◽  
Ronny Leinweber ◽  
Markus Kayser ◽  
...  
Keyword(s):  
Field Experiment ◽  
Temporal Variability ◽  
Surface Wind ◽  
Doppler Lidar ◽  
Signal To Noise ◽  
Observation Volume ◽  
Wind Gusts ◽  
Die Profile ◽  
Spatio Temporal

<p>Mit Hilfe von Doppler-Lidar-Systemen, lassen sich die Profile von Windgeschwindigkeit und -richtung in der Atmosphärischen Grenzschicht (AGS) auf der Basis klassischer Messstrategien wie einem VAD-24 Scan (Velocity Azimuth Display mit 24 Strahlrichtungen) zuverlässig bestimmen (Päschke et al., 2015). Für praktische Anwendungen von großem Interesse sind jedoch neben dem mittleren Windprofil auch kurzzeitige Fluktuationen des Windes, wie sie zum Beispiel in Verbindung mit Windböen auftreten. Untersuchungen zu Windböen waren ein wesentlicher Aspekt der Messkampagne FESSTVaL (Field Experiment on Sub-Mesoscale Spatio-Temporal Variability in Lindenberg, www.fesstval.de).</p><p>Eine Studie von Suomi et al. (2017) hat gezeigt, dass eine Ableitung von Windböen aus Doppler Lidar Messungen prinzipiell möglich ist. Allerdings wird mit üblichen Messstrategien die hierfür erforderliche hohe zeitliche Auflösung in der Ermittlung des Windvektors nicht erreicht, so dass mit Skalierungsansätzen unter Verwendung von in-situ Windmessungen eine Korrektur der aus den Lidar-Daten abgeleiteten Böenwerte erfolgen muss.</p><p>Im Rahmen der vorliegenden Arbeit wurde eine alternative Messstrategie für Doppler-Lidar-Systeme vom Typ „Streamline“ (Halo Photonics) entwickelt und über mehrere Monate in den Jahren 2020/21 auf dem Grenzschichtmessfeld Falkenberg des DWD erprobt. Die Böenableitung basiert auf einem sog. Continous Scan Mode (CSM); dabei werden die während einer vollständigen Rotation des Lidar-Scan-Kopfes kontinuierlich durchgeführten Messungen 10-11 Strahlrichtungen zugeordnet und die Radialwindgeschwindigkeiten wiederum mit dem VAD-Verfahren ermittelt. Die Dauer eines Scans beträgt etwa 3.4s, damit kann eine Zeitauflösung erreicht werden, die der heute weit verbreiteten Definition einer Windbö entspricht (3s gleitendes Mittel; WMO (2018)).</p><p>Diese neue Konfiguration bringt Herausforderungen an die Datenverarbeitung mit sich. Im CSM muss mit vergleichsweise wenigen Lidar-Pulsen pro Messstrahl gearbeitet werden, so dass klassische Ansätze der Datenfilterung (Signal-to-Noise Schwellwert, Consensus Filterung) nicht verwendet werden können. Es wird ein alternatives Verfahren für die Prozessierung der Lidar-Rohdaten vorgeschlagen. Die Ergebnisse der Ableitung sowohl des mittleren Windvektors als auch der jeweiligen maximalen Windbö in einem 10-Minuten-Mittelungsintervall werden mit Sonic-Messungen in 90m Höhe verglichen. </p><p>Im Rahmen des FESSTVaL Experimentes wurde diese neue Messkonfiguration an drei Standorten, die ein annähernd gleichseitiges Dreieck mit einer Kantenlänge von etwa 5 km bildeten, genutzt. Es werden Fallbeispiele aus der FESSTVaL Kampagne für die Variabilität im Auftreten von Windböen gezeigt.</p><p><strong>Referenzen</strong></p><p>Päschke, E., Leinweber, R., and Lehmann, V. (2015): An assessment of the performance of a 1.5 μm Doppler lidar for operational vertical wind profiling based on a 1-year trial, Atmos. Meas. Tech., 8, 2251–2266, https://doi.org/10.5194/amt-8-2251-2015</p><p>Suomi, I., Gryning, S.‐E., O'Connor, E.J. and Vihma, T. (2017): Methodology for obtaining wind gusts using Doppler lidar. Q.J.R. Meteorol. Soc., 143: 2061-2072. https://doi.org/10.1002/qj.3059</p><p>World Meteorological Organization (WMO) (2018): Measurement of surface wind. In Guide to Meteorological Instruments and Methods of Observation, Volume I -Measurement of Meteorological Variables, No.8: 196–213, URL: https://library.wmo.int/doc_num.php?explnum_id=10616 (accessed November 2021)</p>

Midlatitude cyclones in convection permitting climate simulations: the added value offered for extreme wind speeds and sting-jets

2021 ◽  
Author(s):  
Colin Manning ◽  
Elizabeth Kendon ◽  
Hayley Fowler ◽  
Nigel Roberts ◽  
Segolene Berthou ◽  
...  
Keyword(s):  
Climate Model ◽  
Surface Wind ◽  
Added Value ◽  
Large Contribution ◽  
High Wind ◽  
Wind Speeds ◽  
Wind Gusts ◽  
Climate Simulations ◽  
Extreme Wind ◽  
Extreme Wind Speeds

<p>Extra-tropical windstorms are one of the costliest natural hazards affecting Europe, and windstorms that develop a phenomenon known as a sting-jet account for some of the most damaging storms. A sting-jet (SJ) is a mesoscale core of high wind speeds that occurs in particular types of cyclones, specifically Shapiro-Keyser (SK) cyclones, and can produce extremely damaging surface wind gusts. High-resolution climate models are required to adequately model SJs and so it is difficult to gauge their contribution to current and future wind risk. In this study, we develop a low-cost methodology to automate the detection of sting jets, using the characteristic warm seclusion of SK cyclones and the slantwise descent of high wind speeds, within pan-European 2.2km convection-permitting climate model (CPM) simulations. Following this, we quantify the contribution of such storms to wind risk in Northern Europe in current and future climate simulations, and secondly assess the added value offered by the CPM compared to a traditional coarse-resolution climate model. This presentation will give an overview of the developed methods and the results of our analysis.</p><p>Comparing with observations, we find that the representation of wind gusts is improved in the CPM compared to ERA-Interim reanalysis data. Storm severity metrics indicate that SK cyclones account for the majority of the most damaging windstorms. The future simulation produces a large increase (>100%) in the number of storms exceeding high thresholds of the storm metric, with a large contribution to this change (40%) coming from windstorms in which a sting-jet is detected. Finally, we see a systematic underestimation in the GCM compared to the CPM in the frequency of extreme wind speeds at 850hPa in the cold sector of cyclones, likely related to better representation of sting-jets and the cold conveyor belt in the CPM. This underestimation is between 20-40% and increases with increasing wind speed above 35m/s. We conclude that the CPM adds value in the representation of severe surface wind gusts, providing more reliable future projections and improved input for impact models.</p>

scholarly journals Decentralized 3D Collision Avoidance for Multiple UAVs in Outdoor Environments

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4101 ◽  
Author(s):  
Eduardo Ferrera ◽  
Alfonso Alcántara ◽  
Jesús Capitán ◽  
Angel Castaño ◽  
Pedro Marrón ◽  
...  
Keyword(s):  
Collision Avoidance ◽  
System Integration ◽  
Field Experiments ◽  
Positioning Systems ◽  
Wind Gusts ◽  
Aerial Vehicles ◽  
Multiple Uavs ◽  
Outdoor Environments ◽  
External Conditions ◽  
Field Experimentation

The use of multiple aerial vehicles for autonomous missions is turning into commonplace. In many of these applications, the Unmanned Aerial Vehicles (UAVs) have to cooperate and navigate in a shared airspace, becoming 3D collision avoidance a relevant issue. Outdoor scenarios impose additional challenges: (i) accurate positioning systems are costly; (ii) communication can be unreliable or delayed; and (iii) external conditions like wind gusts affect UAVs’ maneuverability. In this paper, we present 3D-SWAP, a decentralized algorithm for 3D collision avoidance with multiple UAVs. 3D-SWAP operates reactively without high computational requirements and allows UAVs to integrate measurements from their local sensors with positions of other teammates within communication range. We tested 3D-SWAP with our team of custom-designed UAVs. First, we used a Software-In-The-Loop simulator for system integration and evaluation. Second, we run field experiments with up to three UAVs in an outdoor scenario with uncontrolled conditions (i.e., noisy positioning systems, wind gusts, etc). We report our results and our procedures for this field experimentation.

On the Variation of Maximum Wind Gusts with Height

1970 ◽  
Vol 9 (1) ◽  
pp. 72-78 ◽  
Author(s):  
R. R. Brook ◽  
K. T. Spillane
Keyword(s):  
Maximum Wind ◽  
Wind Gusts
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