- #1
darrellcro
- 2
- 0
Or any specific requirments formulas that will help me on my way in building one please.
Moderator's note: this thread is from 2008.
Moderator's note: this thread is from 2008.
Last edited by a moderator:
Topher925 said:You are going to need to do a LOT of reading if you want to build your own. If you are serious about having a wind turbine to power your home, your better off going out and buying a commercial unit unless you are a master at electrical power systems. There are no actual plans that I know of since no one wants the liability but there is plenty of information. I recommend starting with http://books.google.com/books?id=WeVSAAAAMAAJ&q=wind+turbine+control&dq=wind+turbine+control&pgis=1" and make sure you have a solid foundation of power electronics and control. Including a solid knowledge of PMSMs and SFIMs along with different methods of control them, especially DTC and SVM.
Next you will need to decide what kind of turbine you want (VS,VP), what kind of power output, cut in speed, cut out speed, and you will also need to know a lot about your wind conditions. That is average wind velocities, capacity factors, wind variance, and velocity distribution.
If you need any more info or help let me know, I sort of an expert on the subject.
maybe you misread the original post.
mshinavar said:maybe you misread the original post. i would guess he is asking about something like this:
http://www.iflyhollywood.com/
otherwise known as vertical wind tunnels
"i want to build my own wind tunnel" vs. "i want to build my own wind turbine"
Mech_Engineer said:It is my suspicion that a sky-diving wind tunnel like you are proposing will have very large power requirements. If my calculations are correct, a 10 ft. diameter wind tunnel with a speed of 120 mph (approximate terminal velocity of a skydiver in the "flat" oriantation) would need 690 kW (925 hp, about $90 per hour using average electrical prices) just for the required kinetic energy of the air going through the tunnel (assuming the air is accelerated from still outside air, not a closed-loop system), not including drag losses in the tunnel which would increase the power requirement.
A wind tunnel of the same dimensions with a speed of 200 mph (skydiver going down headfirst) would require approximately 3.2 MW (4300 hp, $415 per hour).
pwscottiv said:How did you calculate the power requirements? The published values I've seen for wind tunnels are around 1000-1400hp and can achieve up to 180mph wind speed. The one I flew in had five ducted five-blade fans that were about 24in dia with the electric motor in the center of each housing. Also, $90/hr is a bargain, when you consider that they charge around $850/hr to fly in the tunnel. I'd definitely consider building one if I had the time and resources.
Mech_Engineer said:For the calculations I just basically figure out the mass of air you would have going though a 10 ft diameter tunnel at 120 mph, and calculate the kinetic energy per time that would be required to accelerate that air. I'm actually suprised I got as close to the published values as I did, considering the gross simplicity of the calculation...
pwscottiv said:Just curious. 1000HP is definitely a lot less than 4300HP though... Especially if I'd be paying for the power.
There are a few that claim they can get up to 180mph, but http://www.bodyflight.co.uk/about/" is the largest at 16.4ft (5m) diameter. Which is also much more powerful than any other wind tunnel in the world at 4000HP. There is a larger diameter tunnel in Las Vegas, but their wind speed is only about 90mph (which kinda sucks).Mech_Engineer said:BUT- what's the diameter of the wind tunnel that can go up to 180 mph?
pwscottiv said:There are a few that claim they can get up to 180mph,
pwscottiv said:but http://www.bodyflight.co.uk/about/" is the largest at 16.4ft (5m) diameter. Which is also much more powerful than any other wind tunnel in the world at 4000HP. There is a larger diameter tunnel in Las Vegas, but their wind speed is only about 90mph (which kinda sucks).
Mech_Engineer said:Well it takes power to go that fast, so my guess is they're a smaller diameter and higher in power than most. There's no escaping the required kinetic energy with an open loop wind tunnel (closed loop a.k.a. recirculating tunnels are different and can't be compared to open loop in terms of power requirements).
My guess, at 16ft in diameter and 4000hp that wind tunnel's velocity is around 120-150 mph, am I right?
I'm betting that for just a "regularly" sized wind tunnel and "regular" air velocities of 100-120 mph you need over 1000hp, and it basically goes up as the square (or even cube) of the diameter and the square of the velocity from there.
pwscottiv said:I'm an ME too, but I didn't bother doing the calcs... They're claiming that they get 180mph in the 16.5 foot tunnel... I doubt they're lying. Most tunnels are around 12 ft, have around 1200hp and operate up to 160mph or so.
This this is a great project, would love to know if you go and do it.CPTMAC said:Ok, the issue I see with the above scenario is that he is not calculating any drive gearing into the equation, for pure shaft power output he is right.
So what you will need are the following components;
A large stable mesh platform to mount several large fans under.
I suggest a series of 3-4, 8-14 foot fans. Each fan needs to have spacing of 2-3 feet to allow pressure to build up in between the fans. They will need to be mounted in a fairly airtight circular structure with 2-3 feet above them before the mesh for the bottom of the high pressure/speed tunnel.
The Air Intakes will need to be screened and well protected to avoid sucking in particles which, accelerated to 130-180 MPH, could kill someone.
A high horsepower V-8 engine connected to the right gear box can easily put out enough power to send 4 or 5 people 10-15 feet off the mesh if the tunnel is built open or closed above the fans, you will probably burn the equivalent of about 4-8 mpg of unleaded gasoline, depending on your engine. V-8 engines routinely accelerate (with proper gearing) 3000+ pound Nascars to well over 200 mph, 4 or 5 180-230 lb people in a column of air should be no problem
v/r
MAC
kamkaze said:can i build it with 4 4ft props with 4 50hp on each prop electric motors powerd by diesel generator? i think that 4 motors 2800rpm each can build more than enogh speed..
pls reply back because i am in the middle of buying the right props and motors
Redbelly98 said:Moderator's note: this thread is from August, 2008.
Exris said:This is manufacturer of wind tunnel with several projects. Prices starts with 130k euro and higher.
http://www.aerodium-technologies.com/en/products/models/
pwscottiv said:LOL, ok, that's just plain WRONG teasing me like that... The website is down :grumpy:.
Exris said:Strange, for me it's opening without any problems.
Just try to google: aerodium technologies. They models shown in section - products.
moakley2013 said:I constantly search for VWT info on the Internet so came across this thread. I think I can add some substantial information. Please check my FB group, Midwest Vertical Wind Tunnels at
https://www.facebook.com/groups/417365271639837/
This group is open to anyone with interest in VWTs.
Welcome to PF.Amit Patel said:Hi we are building a outdoor open mobile vertical wind tunnel in India.
Its a diesel based model 550 HP Cummins Engine.
Powering a 7 feet diameter axial fan @ 1800 -2000 RPM connect thru a vertical bevel gear box having ratio 1: 1.25
We need to understand if the above calculations are correct and wind velocity of 200 KPMH can be achieved.