Questions tagged [wind-power]
For questions related to power (mechanical or electrical) generated from wind.
45
questions
2
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2answers
109 views
How do 3 blade turbines come so close to the Betz Limit?
I have seen many diagrams (see attached) that indicate that modern 3 blade turbines are nearly 50% efficient, which is about 80% of the Betz limit.
Betz calculated his limit based on a theoretical ...
0
votes
3answers
43 views
Are wind powered drones and platforms possible?
A glider is able to fly unpowered indefinitely so long as it can exploit nearby thermals and the like to stay aloft.
The world record is 3,008km so perhaps there is a practical limit.
I imagine this ...
0
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0answers
34 views
What is the simplest way to convert this oscillating angular motion to (incremental)rotation? and some Q on viability of lin. wind energy extraction
Intro;
I'm currently obsessing over linear energy extraction from wind; a surface to extract the maximum amount of energy from wind in one stroke, then rotating/changing shape on the aerodynamic ...
0
votes
5answers
73 views
Small water pump powered by wind turbine : what type?
I need to aerate a small pond in my garden. I would like to build an autonomous system with a small water pump. The power would come from a small vertical wind turbine I will build. Since my pond is ...
1
vote
1answer
27 views
Weibull distribution Units - ENGIEQSOL
I am using Engineering Equation Solver, and it has been telling me the units of my distribution are inconsistent.
According to a the book I am reading, I think it should be unitless (as it is a ...
-1
votes
2answers
71 views
Correct wind Weibull distribution for wind+solar system
I'm trying to forecast the peak power output for a wind + solar system. The solar output as a function of time of day and month can be forecasted easily. I also have the historical wind speed for a ...
0
votes
0answers
21 views
TSR of a wind turbine
I wanted to ask that if we are given the ratio of rotor length to radius to be 2 and asked to find the TSR for a 3 blade rotor, will we use the following expression:
$$ \lambda_{optimal} = \...
0
votes
0answers
20 views
Shadow flicker validation
I am currently trying to validate a shadow flickering algorithm against some data generated by Openwind. The goal of this validation is to have a code that we know that is correct and modify it to ...
-1
votes
1answer
70 views
Capacity credit vs capacity factor
What is the difference between capacity factor and capacity credit? I know that capacity factor = annual generation / (installed capacity * 8760) but I don't understand how capacity credit is ...
-1
votes
1answer
42 views
Wind turbine that is efficiant from all angles [closed]
What shape propeller with a large surface are, would be best propelled from the wind from behind and from the side as well as the front while facing the sun?
I am thinking a pinwheel, but maybe there ...
1
vote
1answer
82 views
Is a geared motor better for a DIY wind turbine?
I have decent electronic understanding, but I've not much idea about motors.
I plan to make a small wind mill which should be enough to power a couple of LED lights for like an hour every day. I was ...
-1
votes
1answer
19 views
How can I get more power out from a windmill motor?
As far my knowledge a dynamo is a motor which provides electricity when the rotor shaft is rotated. My Question to be brief is if I connect multiple dynamos in a single shaft will I get more current? ...
1
vote
0answers
28 views
Can you channel more air into a nozzle by creating a vortex inside of it?
There are designs for ducting in wind turbines to channel a wider cross section of wind into the rotor area. This is unpractical for structural and economical reasons but does actually increase power ...
1
vote
0answers
36 views
Superimposing a Vector Field onto a Toroid in Matlab
I am a systems and control PhD student in Aerospace Engineering. Currently, I am trying to create a wind shear model of a toroidal thermal "bubble" in Matlab similar to the one in this paper (shown ...
0
votes
2answers
39 views
number of electric vehicles that can be charged with specific amount of energy
I used minutely sampled wind speed data for one year to calculate the yield power from specific wind turbines to be used in electric vehicles charging station.
I am supposed to calculate the number ...
-1
votes
2answers
39 views
What is and how do you calculate the wind velocity design for wind turbines?
I am finding it difficult to get consensus on the definition of design wind speed for aeolic turbines.
I thought it was the velocity that corresponds to the maximum power output, but I have already ...
0
votes
1answer
27 views
small gearbox for experimental wind mill
The gear box will have little torque as I am only using a 12 by 18" wing which rotates. The two shafts I am using are 1/4 ", one form the wing and the other going the to pivot for the wing to circle, ...
1
vote
0answers
39 views
Conceiving a wind turbine as a thermodynamic machine
Traditionally, and continuing till the present day, wind turbines are conceived/presented as power plants which harvest the (macroscopic) kinetic energy carried by an externally available airflow, ...
1
vote
1answer
45 views
How to estimate wind generation using power curve?
I am trying to verify windfarmer generation estimates manually. To do so I am trying to manually calculate the estimated energy production (kWh) of a wind turbine. The information I have available is ...
2
votes
4answers
126 views
Wind turbines with down tower power units. Why aren't they more common?
Concerning the big megawatt wind turbines, if there is such a big trouble with gearbox bearings failing much earlier than expected and costly maintanence or replacement of huge gearboxes, what is ...
4
votes
2answers
141 views
Do 3 blade wind turbines generate more power than a 9 blade, all else being equal?
After doing some research, I have come to the realization that 3 blade design horizontal turbines have the greatest maximum coefficient of performance. Most sources seem to agree a Cp of ~0.45 at TSR=...
2
votes
1answer
92 views
In horizontal axis wind turbines, why does axial component of absolute velocity stay constant (wake rotation theory)
I am having hard time understanding how does the axial component stay constant through the rotor. Every resource i look just says it is due to mass conservation but never gives the actual conservation ...
1
vote
2answers
75 views
Can a bridge's towers be used as wind turbines?
I come from a fairly remote island where we need a 150 min ferry ride to reach the mainland.
While the island has few resources that would encourage a government to investigate the possibility of a ...
0
votes
2answers
153 views
Why vertical wind turbine don't be half covered
I think it would be more efficient for a vertical wind turbine to have a covered funnel about half of it
Something like this figure
It would protected the turbine from opposite wind and also ...
1
vote
0answers
30 views
Hybrid Energy Monitoring Systems
I have been doing research on renewable energy systems and I must admit that I am a newbie in this specific area. I have noticed that stand-alone systems have their own specific monitoring system ...
0
votes
2answers
64 views
Is it possible to generate energy from indoor draft by opening windows on opposite sides of the building?
Wind flow always generates naturally when I opening windows on the opposite sides of the building.
Is it possible to put turbine on the way and generate electricity from that?
It could be optimising ...
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votes
1answer
32 views
How is the Ampyx Power plain generating energy? [closed]
This is what I'm talking about:
Wikipedia
Youtube video 1
Youtube video 2
Official site
Can you please explain me on how this plane is generating energy? Reeling back the aircraft should consume the ...
1
vote
2answers
2k views
what is 1P frequency in rotor (wind turbine)?
In wind turbine, Is the number of revolution taken in 1s is called 1P frequency? If not, is it possible to find the 1P rpm from rpm measured for 1 hour (that is, I have 60 rpm data points from ...
0
votes
3answers
60 views
What determines the cost of the wind turbines?
If there is an 11kW wind turbine, and a 15kW wind turbine. Why is the 15 kw wind turbine more expensive?
I know it seems like a basic question, but what exactly makes it more expensive? Is it only ...
0
votes
3answers
371 views
Wind measure with strain gauge
I'm trying to build my own weatherstation for my home, I want to measure temperature humidity and wind strenght and direction. For the wind I have a question. I want to measure the wind with a ball on ...
1
vote
1answer
61 views
Is it possible to determine tip-speed ratio from rotor geometry?
Let's say I have the geometry of the rotor: the number of blades, the airfoils that make up each blade, their position, chord length and their twist angle. Would it be possible to use this information ...
3
votes
3answers
725 views
Why not design a Wind Turbine like an Anemometer?
Anemometer measures wind speed. It's shaped with little cups---hollow half-spheres. That looks very logical as the cups grab the wind and the other side is rather streamligned to cut through the air ...
1
vote
5answers
377 views
Why isn't it possible to build a car moved by wind power?
So, first of all, I am a High School student and I wanted you to explain me something (in a more "concrete" way, if you know what I mean): I had an idea the other day to make a car with a wind turbine ...
5
votes
2answers
3k views
Advantages/Disadvantages of two-bladed windmill?
The vast majority of wind turbines I have ever seen feature 3 blades, as shown here:
Recently while driving through western new York state, however, I passed by several turbines featuring only two ...
0
votes
1answer
261 views
Why did my result show “more blades on turbine = more RPM”?
I placed a normal cooling fan 45cm away from a small turbine generator. i had 3 turbines, one with 4 blades, 8 blades, and 12 blades.
The one with 12 blades always rotated the fastest, even after ...
4
votes
1answer
345 views
Why does my model of a wind turbine show high RPM with low power output?
I am designing a wind turbine to generate 1300 W.
I modeled the output voltage of an AC generator using the following specifics:
Number coil turns = 300.
Copper wire gauge = 1.02 mm.
Knowing the ...
11
votes
1answer
2k views
How to calculate Power of motor when used as a generator?
How can you calculate how much power can be generated by a motor when used as a generator (like a motor used in a wind turbine)?
Does the power depend on how fast the magnet is rotated? If so, is ...
10
votes
2answers
700 views
Why don't we just build a giant wind turbine?
The power generated by a wind turbine is given by:
$$\mathrm{Power} = \frac{1}{2}C\rho AV^3$$
Where:
$\rho = \text{Air density}$
$C = \text{Coefficient of performance}$
$A = \text{Frontal area}$
$V ...
-2
votes
1answer
118 views
What theoretical efficiencies can wind / hydro turbines achieve? [closed]
The high water has some energy E = mgh. In the basic school, we were told that hydropower plants extract the energy of "falling water". Now, that banned principle says that if your water falls upon ...
5
votes
2answers
4k views
Relationship between wind velocity, turbine rotor diameter, and power output
I'm trying to understand and identify the equations to use in defining the relationship between wind velocity, turbine rotor diameter, and power output for a wind turbine.
To simplify my question, ...
3
votes
1answer
164 views
What is the power and max flow rate required to rotate a 300 W wind turbine?
I have purchased a wind turbine with a power of 300 W, the start up wind speed is 2.5 m/s, rated wind speed is 11 m/s, and the survival wind speed is 45 m/s, and what I'm going to do is to make an ...
4
votes
2answers
587 views
Efficient 3D mesh topology for CFD simulation of turbine blade
I´m developing a tool to generate an openFoam wind tunnel case of a wind turbine. I already have the blade geometry constructed, but I'm really new to CFD and parametric meshing. I found some ...
7
votes
1answer
91 views
To what degree are wind and water turbines exchangeable?
Assuming maximum efficiency is not the primary concern (but net positive efficiency is), to what extent could a wind turbine operate in water and vice versa?
How do the different turbine types fare ...
5
votes
2answers
291 views
Identifying category of wind turbine
I recently saw a wind turbine that I'm trying to identify the type or category of.
Basically, the turbine looks like two squirrel cage fans mounted side by side on a fairly tall ~40' pole.
The ...
13
votes
3answers
286 views
How to correctly size the blades for a small educational wind turbine?
I want to design a small wind turbine that can be easily carried out of the classroom into the sports field in relatively low-wind conditions (5-15km/h) that can power a small ultra-bright 5V LED - ...
