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# Wind Engineering - Science topic

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Questions related to Wind Engineering

Hello,

I have measurements of wind speed from three-components ultrasonic anemometers. I need to calculate the integral length scale and power spectrum. I have used the standard procedure for this, i. e. calculate the fluctuation of the chosen component of the signal of wind speed, then the autocorrelation curve of the component , integrate the autocorrelation curve up to the first zero crossing and multiply the integral with mean wind speed. However, the mean wind speed can be negative, as the anemometer can measure wind component in both directions. Obviously, the integral of the autocorrelation curve can be only positive. Then I get negative integral length scale as a result of the negative mean wind speed. How would you solve this? Would it be correct to use the absolute value of the wind speed? Thanks for your ideas.

I am micro-siting wind turbines in WAsP.

I need to optimize the layout obtained after micro-siting using open-source optimization software.

We know wind turbines extract energy from the wind in order to produce electricity, the wind downstream of a turbine has a lower energy content than the wind upstream. Suppose, the understudy region is formed of two zones (Figure attached). In the dark red zone, the initial wind velocity is greater than that in the light red zone.

Bearing in mind the different initial wind velocities, How to determine the resulting wind speed, due to the wake effect of turbine 1 on turbine 2 (case 1) and of turbine 3 on turbine 4 (case 2)?

Scenario: The problem in case 2, perhaps the recovered wind speed at turbine 4 is greater than V

_{0}=8 m/s (initial speed at light red region)In Serra Gaúcha of Rio Grande do Sul, Brasil, our researches have been stated several deficiences in wind flow determination, to setting up a airblast sprayer.

Seismic design takes advantage of larger damping owing to structure ductility to reduce the design load by R factor (of 3 to 8 value). Apparently, both seismic and wind governing loads are derived from similarly rare event at about 500 years return period, although some recent codes use 2/3 of MCE 2500yrs for seismic. But why only seismic design allows some structural yielding and acceptable damage, while wind design should remain elastic? Is there some concept that I misunderstand?

I actually want to design a prototype system which constantly supply air to the wind turbine. Generally wind turbines are efficient in some particular windy seasons. So I thought about Artificially cause the wind to flow by concept of maintaining pressure difference in between two regions. Can it will possible to do that?

Hi, I want to get three years of hourly wind speed data at 50 meters height for specific locations in Turkey. Unfortunately, I couldn't find any good websites for this. Do you know any online sources for this?

I want to analyze the results of a wind tunnel setup. Is there any manual with the detail of it? How does it work? Different components and the detailed analysis of results...

For hexahedral meshing, it is quite simple to divide one edge in a particular number of division. But for tetrahedral meshing it is not that simple. If we are using a complicated domain for aerodynamic flow and if it is difficult for doing the hexahedral meshing, then how to divide the edge in element in that fashion and what thing must be kept in mind while doing the grid convergence study.

I think factors such as height above ground level, surface roughness, temperature, solar radiation, humidity, pressure, and the slope of the earth can be influential.Which factors have the most impact and which one has the least impact?

Which blades is most efficiency and often used to design wind turbine horizontal axis? Where I will find the perfil alar?

I'm looking for historical wind speed data in Vietnam for coastal areas. Data can be 10 or 2-min. averaged. The data will be used for extreme wind speed and recurrence period analysis that is why I need data for as long period of time as possible.

While going through the ASCE 7-16, I encountered with the equation C26.11-8 under chapter 26 '

**Wind loads: General Requirements**'. fn1=150/h (ft) ------------- Equation (C26.11-8)

There is a reference to two papers by Zhou and Kareem. However, I couldn't quite grasp the idea on how the equation was derived and wanted to know if that equation is reliable to use?

Thank you so much for your time.

Actually I'm trying to generate wind direction and velocity using sentinel

1 images.

But I'm having some problems.

After processing the imaging, using Sentinel 1 toolbox (SNAP), we have been

obtained this kind of image (see file attached). In this image appears

wind direction (with ambiguity) and velocity in m/s.

Where I tried to export these parameters those that are exported are in

the .txt file attached.

My questions is: 1 - How to extract the wind velocity from these image and

export it in as made in .txt file attached ?

2 - How eliminate the ambiguity in order to obtain the

wind direction?

Do you know anybody that is working in these theme using sentinel 1 data

in order to help me.

With my best regards,

geraldo

At Present i am working on Building Aerodynamic, i have modeled a group building models and analysed in CFD. Now, I want to verify my result in wind tunnel. I am getting problem in scale down model according to non-dimensional analysis, to match Reynolds number for model and prototype.

What is the most accurate way of calculating wind direction (2D NESW), wind speed and vertical wind movement using 3D Ultrasonic Anemometer data in the form of uX-uY-uZ m/s (or U-V-W vector) data? I am looking for calculations, methods and/or sources for these approaches.

Hey,

I am working on the Multi body dynamics of a 300kW VAWT as part of my graduation thesis. I have created a reduced order model of the turbine using SIMPACK (MBD solver from dassault systems). I am facing some difficulties with running modal analysis due to error in modal matrix being singular.

I am reaching out to people who have worked with SIMPACK, hoping to get some help with my model .

I'm looking for the airfoil characteristics for SAND 0018/50 (SANDIA 0018/50) that is used wind turbine (VAWT of Darrieus type) tabulated for different Angle of attack and Reynold number?

Any suggestions are highly welcome.

I found that energy efficiency deals with combustion efficiency, using biomass fuels and stuff like that. Can we link between wind energy and energy efficiency by some means?

How could I use this tool to reach to wind pressure distribution over simulated building and How could I deal generally with the results?

Thank you

People feel uncomfortable in the upper stairs of the tall building when the building move laterally due to wind load or to be accurate the lateral acceleration of the building. Is their any recommendations or limits in code provisions for this acceleration.

Thanks

Could wind tunnel provide accurate results to wind load distribution over the building?

What if the building is very flexible like cable stayed bridges or tall building. Could it be simulated using wind tunnel?

As far as I know, almost always the mechanism of the design of wind turbines is for one direction, which it generates electricity-power based on one way of the main wind in the particular region where is installed and it has been designed for the best efficiency of it, however my question is that regardless the mechanism of the turbine, should we consider the effects of the opposite direction wind, i.e. effects like the fatigue phenomenon for designing the most effected parts of the whole structure like the foundation of it?

In textbook I read this sentence "In the case of positive aerodynamic damping the forces generated by motion through the airstream tend to oppose the motion. Negative damping tends to reinforce the motion. "

Why the damping is negative?

What is the physical meaning of the aerodynamic damping?

& is there anyway to apply internal and external pressure coefficient in staad?

if yes,How can we calculate that value(based on IS code)

I have a boundary layer wind tunnel, and I have Pitot Tube Dwyer 160E. And I need to use a differential pressure sensor to have measures between 0 - 30 m/s, or 0 to 500 Pa. Can you recommend a good one, Please

looking for data for 2-3 years

I have a question on wind flow around the building using CFD. Why the most of the people are using steady RANS (RANS) models instead of Transient (URANS and LES). The flow will be stochastic turbulence in nature, but most of the reputed papers on wind flow around the building, ventilation, pedestrian comfort etc.., are used SRANS (STEADY RANS), models.

Thanks advance

looking forward the answers.

LCOE = NPV(CAPEX+OPEX)/NPV(GENR)

or

LCOE = CAPEX+NPV(OPEX)/NPV(GEN)

Wind turbines convert the kinetic energy in the wind into mechanical power. This mechanical power can be converted to electricity.Wind turbines have been used as a source of renewable energy for generating electricity in certain countries without others. What are the most important factors limiting the installation and use of wind turbines to generate electricity in a particular area?

I need to calculate the forces caused by vortex shedding(or vortex induced vibrations) on a tapered cantilever structure under wind loading.

I did some reading and some researchers suggests to calculate the response using some empirical equations to include the motion induced forces due to lock in and negative damping as I understood.

Your advice and suggestions will be appreciated.

In analysis of lattice towers in wind why only dynamic analysis done. What about the static pressures of stagnation due to incidence of wind ?

In the analysis of wind energy cost, Investment (I) is included and covers the turbine price plus 20% for civil work and other connections. For a machine size above 600kW, I would like to have an actualized reference about the specific cost of wind turbines for different size ranges.

Hello

I am working on Flow Control in Wind Turbines and as a startup I need to select the airfoil and design the blade in accordance.Power coefficient is taken generally as 0.4 as I have taken 3 bladed turbine and efficiency to be 0.9.Can anyone tell me what is the conventional steps to be followed while designing the blade?Should I fix the rotor diameter before going for design? In that case how I can fix the rotor diameter?

Thanks in advance

Hello, I have a HAWT blade and I want to know what is the value of the chord of it because we have many chord lengths of the same airfoil due to the loft technique...Thanks

Hello

I am focusing on Wind turbine blade design with flow controls and as a preliminary work,I have to design the blade.WInd turbine blades are not like the conventional wing and they need a different modelling methodology.Can anyone share or tell how to proceed with the blade design and how it can be modeled

How i can combine solar and wind power in one solver in matlab simulink..my solar working on discrete 1e-4 and wind is working on 50e-4 how we can run at same time 1e-4, my solver is backward euler

There are PMIG and DFIG Technology which is used as recent wind turbine in operation in india and in other country

Recently, some engineers have patented Magnus type wind turbines with a number of rotating cylinders acting as blades. Some of these wind turbines use spiral ribs along the cylindrical blades to improve the lift-to-drag ratio. I have some doubts about the real effectiveness of such blades especially from the point of view of the net power output. Are here any experts or anyone who studied it?

I have analysed the unsteady forces calculated by FAST v7 to get the periodical unsteady forces to check the fatigue due to them.

I got fn and ft for 30 station on the HAW blade of 7m length.

The time length was 151 seconds and step was 0.004 s.

My procedure was to get the max fn in each time step and assuming it is acting on the blade at this time neglecting the position and the other components to simplify my analysis.

I made fft analysis and got the periodical ones and I assumed that for the next 151 seconds these forces will repeat themselves.

The results of fft (Fn vs frequency) and fn in time domain is shown below

Can you tell me your opinion on this procedure?

can we discuses some of necessary requirements to avoid the failures in wind turbine ? And how we can calculate the time that the wind turbine is ready for production?

Comparing a building in a low density area, with another one located in a dense urban neighborhood; the wind speed on facades and therefore the temperature of the facade elements varies.

Is the effect of wind speed in such cases marginal or significant? How necessary is that to couple CFD analysis with heating/cooling energy simulation (e.g. using EnergyPlus)?

I would appreciate it if you could reply by referring to valid reference books/scientific papers.

Working in the optimization of power supply to isolated communities with renewable sources. It is necessary to establish the best combination of generating units.

Can anyone give me a complete explanation about using 3 blades on a wind turbine instead of another number especially in the utility-scale wind turbine types?

I need to optimize an airfoil using dynamic characterization for which I need to calculate the pitching moments vs. time. I am very new to GH Bladed. Can anyone suggest me where would I find tutorials for plotting such time varying parameters?

Hello Everyone, I am also facing the problem of TI decaying very fast in my simulation of turbulent flow . I am modeling the flow around 2D square cylinder and used k-e model. I made the model in ADINA and computed the values of k and e based on TI, length scale and mean flow velocity. I don't have the option of entering the turbulent viscosity. So any suggestions on how to solve this problem?

Hi, I am currently an architecture student doing a research study related to wind engineering. I have been using the Australian standards to help me calculate the wind internal pressure and get the external pressure coefficient but I have a problem in understanding when the wind speed is taken at height z. I understand that for leeward and side walls, and roofs the wind speed is mostly taken at height z but for the windward wall, when is the wind speed taken at height z? Thank you.

Hello, I need this model for my thesis, any help would be appreciated.

Hi,

I need statistics regarding annual average wind speeds (preferably at 50 meters height) in India and Pakistan for the period between years 2000 and 2010. I would appreciate if you could kindly guide me how to get such data?

Thanks

Hello

I am working on design of NACA 63415 airfoil for my research.Besides computational methods,I am interested to do the profile mathematically.Can anyone tell me what is the chord length equation for a 6 series NACA airfoils.Thanks

I have the wake height and width behind a scaled down car model from a wind tunnel experiment. I am not sure how to compare the wake of this scaled down model with the actual body and get the estimated height of wake behind the car in actual condition.

I want to analyze a 110 story building for performance based wind engineering, how/where do I get wind load time history data from ?

How can optimizing blade of vertical axis wind turbine by using Ansys Fluent?

And what can Ansys Fluent do?

Thanks.

Why do I get infinite power coefficient solution at the root of wind turbine blade in aerodynamic analysis using blade element momentum theory?

To work out the aerodynamics of vertical axis wind turbine (VAWT) and probably the HAWT, we need to know Reynold number (Re) to use it along with angle of attach to find the drag and lift coefficients (C

_{d}& C_{l}) from the airfoil characteristics,**I would like to know which velocity we use to find Reynold number, Re=v*L/neu,***is it the induced (axial flow) velocity (assuming that MST or DMST is considered), or the relative velocity, or the tangential velocity V*_{t}*=Omega*R?*I design a Darrieus turbine with adjustable blade angles to improve the efficiency of the turbine at low wind speeds.

I am trying to design a wind turbine blade and came across these two methods. Looking at the variation in the chord length these methods have while calculating near the rotor hub, which method provides better practical results?

"disk loading" is also called in some papers " screen factor"

I have the turbulent intensity values derived from the Standard deviation of the mean wind speeds, and the mean wind speeds themselves. I also have the mean yaw position of the turbine.

Can you please give me insight on optimization of wind turbine blade (Mathematical modeling for same)??

You may cite reference for that

Thanks

I am trying to use the wavelet analysis to investigate the trend of the SST and wind speed time series. Now my question is:

How can I use the wavelet analysis to see the trend of time series?

I am very grateful to you if you can provide me the answer of my question and suggest me the useful papers related to this topic. Thank You.

I would like to know whether vertical axis or horizontal axis wind turbine give more structural load to its tower given all other conditions and specifications are the same (power output, height, wind speed). The size may differ for both as long as the rated power output at a given wind speed is the same.

I would like to read about basics of elastic meta materials and its applications in wind turbine blades.

If one is trying to identify the area in the region, where hybrid renewable energy is more appropriate, one would like to

*to be super imposed on one another. This may cater as feasibility analysis before going into the diurnal analysis of complementary nature of VREs at certain location.***combine solar insolation and wind power data**please can someone help me in modeling a wind turbine with a DFIG ? i need your suggestions pllz

The wind turbine would be a savonius or maybe a Darrieus. It would be used for urban zones. High power capacity would not be really needed. The economic factor is really important. So, PMSG?, IG?

The distance between the sonic anemometer transducers decides the lower limit to the size of the eddy being measured. But equally, this distance is also dependent upon the ability of the transducers and associated control and conditioning circuits to respond rapidly enough with the necessary increasing measurement frequency as the transducer separation distance decreases. Also the physical size of the transducers plays an increasingly important role in disturbance of the wind field around the anemometer as the distance shortens. This is an instrument question - not a theoretical one.

Hello, I am working on the simulation of a wind turbine (5MW-Sinovel SL5000).But, I don’t have data of a DFIG generator (5 MW), moment of inertia, coefficient of various friction and gear-box.

Please provide me the data if anybody have it.

Thank you for your help.

What is need of putting

**g**in wind power calculation._{c}does it shows the effect of geographical location on air density or on velocity.

Hi,

I want to get the total output power of a wind farm. I only have an annual wind speed with 10-minute average in one location, but I want to get the information with more information, thus I have to add some turbulence into our measured 10-minute average wind speed.

I don't know how to do it

Hello everyone,

I am developing my graduation project at Unesp Sorocaba - SP Brazil.

I chose as the theme: Fuzzy logic applied in pitch angle control for wind turbines.

I studied a lot about wind turbines and I realized that the generator most used is the DFIG (Double Fed Induction Generator).

But this type of generator is a bit more complex than a SCIG (squirrel cage rotor) or even a PMSG that uses permanent magnets as a stator.

So, I decided to use a SCIG, since the focus of my work is on pitch angle control.

But, the behavior of the generator is really important to the analysis, because I need to compair the results of the power (active and reactive).

This way I have to use reliable parameters that bring reality to my model. And that's my problem. I'm not finding the parameters I need to simulate a wind turbine. I found some data from a turbine made by Vestas, the V39, but aerodynamic parameters can not be found.

I'm using a template in Simulink. I'm adapting this model.

Is there anyone who could help me in this. To point one way. Any tip will help a lot!

i got a Torque as 137797N-m and rotational velocity is 2.22rad/sec.moreover i took fullscale GE1.5xle model whose rated power is 1.5MW.kindly suggest how to get the power coefficient in fluent?

one of the serious problems in Vertical Axis Wind Turbine simulation is negative torque value. I searched the internet and found that TSR<1 (Tip Speed Ratio) result in negative torque value most of the time but in some simulations for TSR<1 , torque values are positive. I am simulating a 2D VAWT in ANSYS Fluent 16.

What is reason for negative torque values? Is there any solution?

appreciate any help.

I searched in possible PhD topic in VAWTs especially the structural mechanics or optimization however most of things I 've found are related to aerodynamics only.