Influence of wind speed, stay cable inclination angle and wind yaw angle on formation of rivulets

The buffeting performance of free-standing tower of JiangHai Navigation Channel Bridge, a cable-stayed bridge, under yaw wind is investigated by means of wind tunnel test of aeroelastic model. It is found that the variation of buffeting response of free-standing tower with wind yaw angle is not monotonous. The lateral buffeting response on the top of the free-standing tower reach their minimal values and maximal values at around 150°and 180°of wind yaw angle respectively and the longitudinal buffeting response attain their maximal values at around 90°of wind yaw angle. Also, at the 2/3 height of the tower the lateral buffeting response and torsional buffeting response get their minimal values at around 150°of wind yaw angle, and at around 180°achieve the maximal values. It is also seen that, the buffeting response changes with the wind speed at a conic curve approximately.

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Numerical studies on aerodynamics of high-speed railway train subjected to strong crosswind

Advances in Mechanical Engineering ◽

10.1177/1687814019887270 ◽

2019 ◽

Vol 11 (11) ◽

pp. 168781401988727

Author(s):

Xu Wang ◽

Yuanhao Qian ◽

Zengshun Chen ◽

Xiao Zhou ◽

Huaqiang Li ◽

...

Keyword(s):

Wind Speed ◽

High Speed ◽

Lift Coefficient ◽

Aerodynamic Characteristics ◽

Width Ratio ◽

Force Coefficient ◽

Rolling Moment ◽

Side Force ◽

Train Speed ◽

Yaw Angle

Under the action of strong crosswind, the aerodynamic behavior of a rail vehicle at high speed will be changed significantly, which could directly affect the safe operation of the vehicle. With the help of the shape of train used in China, the aerodynamic characteristics of trains with scale of 1:1 is investigated using computational fluid dynamics numerical simulation method, which consists of the variation of aerodynamics force and moment with wind yaw angle, wind speed, train speed, and nose shape. After an initial validation against Baker’s results from wind tunnel test, the numerical model is then used to investigate the aerodynamic characteristics of the trains. The numerical results indicate that lift coefficient of the M train is slightly higher than TMC1 and TMC2 trains. Regardless of aerodynamics force coefficients, TMC1 reaches the maximum at a yaw angle of 75°. Aerodynamics force coefficient increases with both wind speed and train speed, but the change of which is not linear. Comparing aerodynamic force with different geometric dimensions of train nose, it is shown that height–width ratio is insensitive to side force and rolling moment, but sensitive to lift force from the yaw angle 0°–90°. The side force coefficient, as we most concern, is less than other results, when the length–width ratio is 1 and height–width is 0.87.

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Effects of central stabilizing barriers on flutter performances of a suspension bridge with a truss-stiffened deck under skew winds

Advances in Structural Engineering ◽

10.1177/1369433218774144 ◽

2018 ◽

Vol 22 (1) ◽

pp. 17-29 ◽

Cited By ~ 4

Author(s):

Ledong Zhu ◽

Xiao Tan ◽

Zhenshan Guo ◽

Quanshun Ding

Keyword(s):

Wind Speed ◽

Wind Tunnel ◽

Inclination Angle ◽

Suspension Bridge ◽

Control Measures ◽

Wind Effect ◽

Wind Condition ◽

Wind Tunnel Tests ◽

Critical Wind Speed ◽

Bridge Span

To improve the flutter performance of a suspension bridge with a 1088-m-span truss-stiffened deck, the aerodynamic measures of upper and lower central stabilizing barriers were investigated at first via wind tunnel tests of sectional model under the normal wind condition. The yaw wind effect on the flutter performance of the bridge with the above aerodynamic measures was then examined via a series of wind tunnel tests of oblique sectional models. The test results show that the effect of the lower central stabilizing barrier on the flutter critical wind speed is remarkably different from that of the upper central stabilizing barrier for both the normal and skew wind cases. The inclination angle +3° is the most unfavorable inclination angle to the flutter performance of the truss-stiffened suspension bridge no matter whether the aerodynamic control measures are adopted or not. Furthermore, for most cases, the lowest flutter critical wind speed occurs when the incident wind deviates from the normal direction of the bridge span by a small yaw angle between 5° and 10°.

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The effect of inclination angle on fire behaviors of stay cable in an intercepted double-layer cable model

Journal of Thermal Analysis and Calorimetry ◽

10.1007/s10973-019-09039-1 ◽

2019 ◽

Vol 140 (6) ◽

pp. 2701-2710

Author(s):

Changkun Chen ◽

Jie Chen ◽

Xiaolong Zhao ◽

Congling Shi

Keyword(s):

Double Layer ◽

Inclination Angle ◽

Stay Cable ◽

Cable Model

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The impact of wind on the rainfall–runoff relationship in urban high-rise building areas

Hydrology and Earth System Sciences ◽

10.5194/hess-25-6023-2021 ◽

2021 ◽

Vol 25 (11) ◽

pp. 6023-6039

Author(s):

Xichao Gao ◽

Zhiyong Yang ◽

Dawei Han ◽

Kai Gao ◽

Qian Zhu

Keyword(s):

Wind Speed ◽

Inclination Angle ◽

Theoretical Framework ◽

Runoff Coefficient ◽

Rainfall Runoff ◽

Wind Drift ◽

High Rise ◽

High Rise Building ◽

The Impact ◽

The Relationship

Abstract. Wind drift has a significant influence on the rainfall–runoff relationship in urban high-rise building areas since the oblique rainfall caused by the wind drift can interact with the building walls. However, the impact of the rainfall inclination angle on the rainfall–runoff process in urban high-rise building areas has not been studied. In this study, the relationship between wind and the rainfall–runoff process in such areas was explored. A theoretical framework has been developed to describe their relationship, including a computational fluid dynamics (CFD) method to obtain the relationship between wind speed and rainfall inclination and a newly derived equation to describe the relationship between rainfall inclination and the runoff coefficient. Subsequently, a laboratory scale model experiment was conducted to verify the proposed framework. The main results are that (1) the runoff coefficient calculated by the proposed theoretical framework is highly consistent with that obtained from the laboratory experiment, (2) the runoff coefficient of urban high-rise building areas increases with wind speed and the increase rate is linear with the tangent of the rainfall inclination angle, and (3) the change in the runoff coefficient for the experiment with larger raindrop is 0.047 when the wind speed increases from 0 to 5.9 m s−1, while that for the experiment with smaller raindrop is 0.064, which means that the rainfall with larger droplets is less influenced by the wind.

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RESEARCH ON THE UNIFORMITY DEGREE OF SOLID ORGANIC FERTILIZERS DISTRIBUTION

INMATEH Agricultural Engineering ◽

10.35633/inmateh-65-51 ◽

2021 ◽

pp. 495-504

Author(s):

Vasilica Stefan ◽

Ana Zaica ◽

Adrian Iosif

Keyword(s):

Wind Speed ◽

Working Conditions ◽

Experimental Research ◽

Inclination Angle ◽

Feed Rate ◽

Organic Fertilizers ◽

Material Function ◽

Soil Fertilization ◽

Number Of Factors

In this paper are presented the results of experimental research conducted in order to improve the uniformity of organic fertilizers distribution (compost and semi-fermented manure) used for soil fertilization, if the administration is done with a machine with a distributor with continuous spiral centrifugal beaters, arranged vertically. The uniformity of organic fertilizers distribution depends on a number of factors such as: the speed and angle of inclination of the distribution device, the distance between the distribution beaters, the humidity and the density of the material, wind speed, the size of the fertilizer particles. The determinations were performed under working conditions and the various parameters were the beaters speed, beaters inclination angle and the feed rate of the distribution device, choosing 3 situations (minimum, average and maximum) for each of them. Based on the obtained results, the multivariable functions of polytropic form was determined, which characterize the degree of uniformity of the spread material, function that can be the basis for the elaboration of constructive solutions to ensure the optimum uniformity of distribution.

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CFD Analysis of Drag Reduction Using External Devices on Pickup Trucks

Volume 11: New Developments in Simulation Methods and Software for Engineering Applications; Safety Engineering, Risk Analysis and Reliability Methods; Transportation Systems ◽

10.1115/imece2010-39732 ◽

2010 ◽

Author(s):

Feysal A. Adem ◽

Dongmei Zhou ◽

Pramod Krishnani

Keyword(s):

Numerical Simulations ◽

Inclination Angle ◽

Cfd Simulation ◽

Aerodynamic Drag ◽

Lift Coefficient ◽

Aerodynamic Drag Coefficient ◽

Zero Degree ◽

Drag And Lift ◽

Drag And Lift Coefficient ◽

Yaw Angle

The flows over a pickup truck with add-on devises were studied using computational fluid dynamics (CFD) with the objective of investigating the effect of these add-no devices on the flow structures around the vehicle, aerodynamic drag, and lift coefficient. All numerical simulations were performed using commercial CFD software Fluent [8]. A generic pickup model with extended cab was used as the base model and all the flow simulations were performed at zero degree yaw angle. The pickup configurations used in the present CFD simulation include Aerocap with different rear inclination angle α, Tonneau cover, Rear Roof Garnish, and Tail-plates. Results from numerical simulations indicated that Aerocap with inclination angle α = 12° and a reduced rear width has produced the minimum aerodynamic drag coefficient. It was also shown that the wake region decrease when the rear inclination angle increases.

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Artificial Neural Network Based Reinforcement Learning for Wind Turbine Yaw Control

Energies ◽

10.3390/en12030436 ◽

2019 ◽

Vol 12 (3) ◽

pp. 436 ◽

Cited By ~ 20

Author(s):

Aitor Saenz-Aguirre ◽

Ekaitz Zulueta ◽

Unai Fernandez-Gamiz ◽

Javier Lozano ◽

Jose Lopez-Guede

Keyword(s):

Neural Network ◽

Artificial Neural Network ◽

Reinforcement Learning ◽

Wind Speed ◽

Wind Turbine ◽

Control Algorithm ◽

Mechanical Loads ◽

Yaw Control ◽

Artificial Neural ◽

Yaw Angle

This paper introduces a novel data driven yaw control algorithm synthesis method based on Reinforcement Learning (RL) for a variable pitch variable speed wind turbine. Yaw control has not been extendedly studied in the literature; in fact, most of the currently considered developments in the scope of the wind energy are oriented to the pitch and speed control. The most important drawbacks of the yaw control are the very large time constants and the strict yaw angle change rate constraints due to the high mechanical loads when the wind turbine angle is changed in order to adequate it to the wind speed orientation. An optimal yaw control algorithm needs to be designed in order to adapt the rotor orientation depending on the wind turbine dynamics and the local wind speed regime. Consequently, the biggest challenge of the yaw control algorithm is to decide the moment and the quantity of the wind turbine orientation variation to achieve the highest quantity of power at each instant, taking into account the constraints derived from the mechanical limitations of the yawing system and the mechanical loads. In this paper, a novel based algorithm based on the RL Q-Learning algorithm is introduced. The first step is to obtain a model of the power generated by the wind turbine (a real onshore wind turbine in this paper) through a power curve, that in conjunction with a conventional proportional regulator will be used to obtain a dataset that explains the actual behaviour of the real wind turbine when a variety of different yaw control commands are imposed. That knowledge is then used to learn the best control action for each different state of the wind turbine with respect to the wind direction represented by the yaw angle, storing that knowledge in a matrix Q(s,a). The last step is to model that matrix through a MultiLayer Perceptron with BackPropagation (MLP-BP) Artificial Neural Network (ANN) to avoid large matrix management and quantification problems. Once that the optimal yaw controller has been synthetized, its performance has been assessed using a number of wind speed realizations obtained using the software application TurbSim, in order to analyze how the introduced novel algorithm deals with different wind speed scenarios.

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DYNAMICS ANALYSIS OF HIGH-SPEED RAILWAY VEHICLES EXCITED BY WIND LOADS

International Journal of Structural Stability and Dynamics ◽

10.1142/s021945541100449x ◽

2011 ◽

Vol 11 (06) ◽

pp. 1103-1118 ◽

Cited By ~ 12

Author(s):

YUNG-CHANG CHENG ◽

CHERN-HWA CHEN ◽

CHE-JUNG YANG

Keyword(s):

Wind Speed ◽

Lateral Displacement ◽

Oscillation Amplitude ◽

Dynamic Responses ◽

Wind Loads ◽

Creep Model ◽

Railway Vehicle ◽

Nonlinear Creep ◽

Car Body ◽

Yaw Angle

Based on Kalker's linear theory and the heuristic nonlinear creep model, the nonlinear coupled differential equations of motion are derived for a vehicle model with 20 degrees of freedom, considering the lateral displacement and yaw angle of each wheelset, the lateral displacement, vertical displacement, roll angle and yaw angle of the bogie frame, and the car body moving on a curved track. The dynamic responses of a railway vehicle with wind loads acting laterally and vertically, and wind moments acting about the longitudinal axis of the car body are investigated. The analysis results indicate that the oscillation amplitude of the car body increases as the wind speed increases. Furthermore, the average amplitude of oscillation of the wheelset increases with the wind speed as well. It is concluded that the influence of wind loads on the dynamic stability of a vehicle cannot be ignored.

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