scholarly journals Extension of REBMIX algorithm to von Mises parametric family for modeling joint distribution of wind speed and direction

2019 ◽  
Vol 183 ◽  
pp. 1134-1145 ◽  
Author(s):  
X.W. Ye ◽  
P.S. Xi ◽  
Marko Nagode
Keyword(s):  
Wind Speed ◽  
Joint Distribution ◽  
Parametric Family ◽  
Von Mises

scholarly journals Influence of Wind Speed, Wind Direction and Turbulence Model for Bridge Hanger: A Case Study

Symmetry ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1633
Author(s):  
Yang Ding ◽  
Shuang-Xi Zhou ◽  
Yong-Qi Wei ◽  
Tong-Lin Yang ◽  
Jing-Liang Dong
Keyword(s):  
Wind Speed ◽  
Wind Direction ◽  
Wind Field ◽  
Solid Mechanics ◽  
Von Mises Stress ◽  
Long Span Bridges ◽  
High Rise ◽  
Long Span ◽  
Cfd Models ◽  
Von Mises

Wind field (e.g., wind speed and wind direction) has the characteristics of randomness, nonlinearity, and uncertainty, which can be critical and even destructive on a long-span bridge’s hangers, such as vortex shedding, galloping, and flutter. Nowadays, the finite element method is widely used for model calculation, such as in long-span bridges and high-rise buildings. In this study, the investigated bridge hanger model was established by COMSOL Multiphysics software, which can calculate fluid dynamics (CFD), solid mechanics, and fluid–solid coupling. Regarding the wind field of bridge hangers, the influence of CFD models, wind speed, and wind direction are investigated. Specifically, the bridge hanger structure has symmetrical characteristics, which can greatly reduce the calculation efficiency. Furthermore, the von Mises stress of bridge hangers is calculated based on fluid–solid coupling.

Joint distribution of wind speed and direction in the context of field measurement

2015 ◽  
Vol 20 (5) ◽  
pp. 701-718 ◽  
Author(s):  
Hao Wang ◽  
Tianyou Tao ◽  
Teng Wu ◽  
Jianxiao Mao ◽  
Aiqun Li
Keyword(s):  
Wind Speed ◽  
Field Measurement ◽  
Joint Distribution

Bridge Design Basic Wind Speed Based on the Joint Distribution of Wind Speed and Direction

2011 ◽  
Vol 90-93 ◽  
pp. 805-812 ◽  
Author(s):  
Zheng Wei Ye ◽  
Yi Qiang Xiang
Keyword(s):  
Wind Speed ◽  
Wind Direction ◽  
Joint Distribution ◽  
Probability Model ◽  
Model Fitting ◽  
Frequency Function ◽  
Actual Distribution ◽  
Extreme Type ◽  
Sampling Intervals ◽  
The Impact

Based on the method of separation of wind speed and direction variable, considering the wind direction frequency function, ascending order to calculate the probability of the actual distribution of the sample, extreme type Ⅰ (Gumbel) and three parameters of extreme type Ⅱ (Frechet) and extreme type Ⅲ (Weibull) probability distribution to fit the sample, this paper has analyzed the weather station observations of 34 consecutive years of the joint distribution of wind speed and direction near to a huge bridge, gained the basic design wind speed in different directions, comparatively analyzed the impact of the sampling interval of change on the basic wind speed as well. The results shows: wind speed in different directions at the same location or different sampling intervals samples of the wind speed sample may be subject to different types of extreme value distribution, should separately fitting; different wind direction frequency of extreme wind speed occurrence and the basic wind speed there are certain differences, taking into account the joint distribution of wind speed and direction is necessary to determine the design basic wind speed of the bridge, and will be conservative without considering the joint distribution; for the same sample wind speed matrix, the shorter the sampling intervals, the optimal distribution of the higher probability model fitting precision, the smaller the basic wind speed, the more economic and reasonable the results.

Global Hierarchical Models for Wind and Wave Contours: Physical Interpretations of the Dependence Functions

2020 ◽  
Author(s):  
Andreas F. Haselsteiner ◽  
Aljoscha Sander ◽  
Jan-Hendrik Ohlendorf ◽  
Klaus-Dieter Thoben
Keyword(s):  
Wind Speed ◽  
Wave Height ◽  
Hierarchical Models ◽  
Significant Wave Height ◽  
Joint Distribution ◽  
Environmental Data ◽  
Contour Method ◽  
Dependence Function ◽  
Significant Wave ◽  
Estimated Parameters

Abstract Applications such as the design of offshore wind turbines requires the estimation of the joint distribution of variables like wind speed, wave height and wave period. The joint distribution can then be used, for example, to define design load cases using the environmental contour method. Often the joint distribution is described using so-called global hierarchical models. In these models, one variable is taken as independent and the other variables are modelled to be conditional on this variable using particular dependence functions. In this paper, we propose to use dependence functions that offer physical interpretation. We define a novel dependence function that describes how the median of the zero-up-crossing period increases with significant wave height and a novel dependence function that describes how the median significant wave height increases with wind speed. These dependence functions allow us to reason about the physical meaning, even when we extrapolate outside the range of a given sample of environmental data. In addition, we can analyze the estimated parameters of the dependence function to speculate which kind of sea dominates at a given site. We fitted statistical models with the proposed dependence functions to six datasets and analyzed the estimated parameters. Then we calculated environmental contours based on these estimated joint distributions. The environmental contours had physically reasonable shapes, even at areas that were outside the datasets that were used to fit the underlying distributions.

Design and Static Structural Analysis of a 2.5 kW Combined Darrieus-Savonius Wind Turbine

2017 ◽  
Vol 30 ◽  
pp. 94-99 ◽  
Author(s):  
Fateh Ferroudji ◽  
Cherif Khelifi ◽  
Farouk Meguellati ◽  
Khaled Koussa
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Three Dimensional ◽  
Wind Pressure ◽  
Galvanized Steel ◽  
Element Analysis ◽  
Critical Loading ◽  
Savonius Wind Turbine ◽  
The Stability ◽  
Von Mises

Modeling and simulation of mechanical structures in development phase are fundamental to optimize and improve the stability and reliability of the final product as well as to reduce the cost of prototyping and testing. Wind turbines are subject to critical loading to the centrifugal force due to wind speed and gravitational force. The present study discusses three-dimensional numerical simulations of combined Darrieus-Savonius wind turbine D-SWT for applications in urban and isolated areas for lighting, pumping water, etc. The Darrieus turbine is used to produce wind power and the Savonius rotor to start the system. Finite Element Analysis (FEA) using SolidWorks 2015 is employed to generate the geometry of the structure and SolidWorks Simulation to investigate the stability and reliability static on the structure of the D-WST built by two types of material of the blade Galvanized Steel (GS) and Aluminum alloys 1060-H18 (ALU). Mechanical parameter of the structure are calculated for critical loading conditions, including the gravity and wind pressure loading due to the wind speed of 23m/s. Simulations results indicate no structural failure is predicted for all components of the D-SWT for both materials used according to Von Mises criterion stresses and the factors of safety of the most fragile material are greater than (the unity) 1. The maximum displacements found (3.84 & 6.81mm), occurred at the tip blades (free ends levels). These displacements are accepted relatively to the structure size.

Design optimization on high-rise buildings considering occupant comfort reliability and joint distribution of wind speed and direction

2018 ◽  
Vol 156 ◽  
pp. 460-471 ◽  
Author(s):  
Jiyang Fu ◽  
Qingxing Zheng ◽  
Youqin Huang ◽  
Jiurong Wu ◽  
Yonglin Pi ◽  
...  
Keyword(s):  
Wind Speed ◽  
Design Optimization ◽  
Joint Distribution ◽  
High Rise ◽  
Occupant Comfort

scholarly journals Modeling directional distributions of wind data in the United Arab Emirates at different elevations

2021 ◽  
Vol 14 (9) ◽  
Author(s):  
Aishah Al Yammahi ◽  
Prashanth R. Marpu ◽  
Taha B. M. J. Ouarda
Keyword(s):  
Wind Speed ◽  
United Arab Emirates ◽  
Wind Direction ◽  
Least Square Method ◽  
Least Square ◽  
Distribution Model ◽  
Long Term Effects ◽  
Energy Potential ◽  
Engineering Structures ◽  
Von Mises

AbstractModeling wind speed and direction are crucial in several applications such as the estimation of wind energy potential and the study of the long-term effects on engineering structures. While there have been several studies on modeling wind speed, studies on modeling wind direction are limited. In this work, we use a mixture of von Mises distributions to model wind direction. Finite mixtures of von Mises (FMVM) distributions are used to model wind directions at two sites in the United Arab Emirates. The parameters of the FMVM distribution are estimated using the least square method. The results of the research show that the FMVM is the best suited distribution model to fit wind direction at these two sites, compared to other distributions commonly used to model wind direction.

Dynamic Response Analysis of Large Wind Turbine Blade Based on Davenport Wind Speed Model

2011 ◽  
Vol 347-353 ◽  
pp. 2330-2336
Author(s):  
Jian Ping Zhang ◽  
Dong Liang Li ◽  
Yu Liu ◽  
He Len Wu ◽  
Jian Xing Ren ◽  
...  
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Vibration Amplitude ◽  
Wind Turbine Blade ◽  
Von Mises Stress ◽  
Growth Trend ◽  
Element Analysis ◽  
Von Mises ◽  
Fluctuating Wind

Fluctuating wind speed spectrum, which is closer to the actual working conditions, was simulated by davenport wind speed model, and displacement and stress distribution of blade under fluctuating wind speed were calculated by finite element analysis software. The numerical results indicate that the growth trend of vibration amplitude for whole blade at flapping direction is nonlinear along the wingspan. The max von-mises stress appears when the vibration amplitude of tip reaches the maximum, and it is mainly concentrated in the central part of the blade. The stress at trailing edge and tip is smaller than the central part. Above results provide a reference for the strength safety design of wind turbine blade.,Fluctuating wind speed spectrum, which is closer to the actual working conditions, was simulated by davenport wind speed model, and displacement and stress distribution of blade under fluctuating wind speed were calculated by finite element analysis software. The numerical results indicate that the growth trend of vibration amplitude for whole blade at flapping direction is nonlinear along the wingspan. The max von-mises stress appears when the vibration amplitude of tip reaches the maximum, and it is mainly concentrated in the central part of the blade. The stress at trailing edge and tip is smaller than the central part. Above results provide a reference for the strength safety design of wind turbine blade.

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