Building a Power-Generating Turbine with an Unmodified Motor

In summary, the team-mates and I are trying to build a turbine that will draw as much power as possible from a box-fan. Every team has been given an identical motor, but they are not allowed to modify it in any way. My research has led me to believe that a better solution would be to build a turbine similar to a gas turbine engine, using a diffuser to increase the velocity and reduce the losses.
  • #1
Hank_Rearden
25
0
hey all,

for a science league competition, my team-mates and I are tasked with building a turbine that will draw as much power from a box-fan as possible. Every team has been given an identical motor and the rules specify that we can't modify the motor at all. I've asked around and it seems like what I should be doing is making my fans as big and light as possible to maximize the amount of force they absorb from the wind. Would anyone be so kind as weigh in?
 
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  • #2
I would say do some research on real life electrical generating wind turbines. They're exactly what you're looking for, and the best solution to the problem has already been found.
 
  • #3
What about adding a diffuser row after the fan, and then dumping into a combustor?

Seriously though, I don't think wind turbine are very effiicient, I think you can do MUCH better by approaching the turbine as you would a turbine stage in a gas turbine engine.
 
  • #4
minger said:
What about adding a diffuser row after the fan, and then dumping into a combustor?

Seriously though, I don't think wind turbine are very effiicient, I think you can do MUCH better by approaching the turbine as you would a turbine stage in a gas turbine engine.
I don't know. You won't have anything for a delta P. A box fan doesn't really give you anything to work with other than velocity. This would be more like an impulse turbine or a Pelton wheel IMO. Perhaps your idea of a diffuser could be switched around and put a nozzle on the outlet of the fan. I have no idea how much the box fan would not like it, but if you could put a plenum and then a nozzle that reduces down to try to get your velocity way up and then point that at a Pelton wheel...
 
  • #5
True box fans aren't going to give you much of; you're ideas not bad though. Velocitie are low so losses are too. You're in effect then reducing the area where you're getting low efficiency. You would at least get points for creativity.
 
  • #6
FredGarvin said:
This would be more like an impulse turbine or a Pelton wheel IMO.

I ashamedly admit that I had to look up 'Pelton wheel' to find out if we were on the same page. Almost, because my first thought was what I know as a 'pinwheel'. That's one of those things that you get at a fair when you're a kid, with usually 4 'blades'. I guess that it's the kindergarten version of a Pelton wheel. Anyhow, my first thought toward this matter is that a few really fat blades with moderate pitch would be more appropriate in this airflow situation than what one would normally think of as a 'turbine', such as the working end of a J-34. Once again, though, my lack of education leaves me wondering...
 
  • #7
the styrofoam kids sail planes may yield up a couple potential blades, and they'd be pretty matched. being as velocity is so low, and flow is very controlled, wouldn't the vertical windmill style be a better fit? have the fan blow on the one side, and then the reverse losses would be decreased because of no wind on them?

dr
 
  • #8
Have you done any research into Pelton wheels as Fred suggested? They have used those in hydroelectricity, which operate typically at significantly higher efficiencies than wind power.

If you check out:
http://en.wikipedia.org/wiki/Water_turbine#Design_and_application

There are some other low-head designs such as Kaplan Turbines
 
  • #9
It would appear that this was a post and run.
 
  • #10
whoops, I actually thought that dr.dodge was the OP. Oh well...
 
  • #11
I'm not sure what a box fan is, but guess that it's a fan with some kind of shroud round the fan. The first thing to do is get the fan working as hard as possible, hokk an ammeter onto your motor feed and see if different diffusers make the fan work harder, when you have the max power coming off the fan you can start to design the turbine for the air speed that you are getting at the diffuser outlet.
 
  • #12
well I need to look up about half of the stuff you guys are saying, especially a pelton wheel, but thanks for all the help
 
  • #13
and sorry for taking so long to reply, the college admissions process has eaten up all of my time lately
 

1. How does a power-generating turbine with an unmodified motor work?

A power-generating turbine with an unmodified motor works by harnessing the rotational energy of the motor and converting it into electrical energy. The motor spins a shaft connected to a turbine, which rotates a magnet inside a coil of wire, creating an electromagnetic field that produces electricity.

2. What types of motors can be used for building a power-generating turbine?

Any type of motor that can rotate at a high speed can be used for building a power-generating turbine. This includes DC motors, AC motors, and even small hobby motors. It is important to choose a motor that is powerful enough to generate a significant amount of electricity.

3. How much electricity can be generated with a power-generating turbine?

The amount of electricity generated depends on the size and power of the motor used. Generally, a small hobby motor can produce enough electricity to power small electronic devices, while a larger motor can generate enough to power a household. It is important to note that the efficiency of the turbine also plays a role in the amount of electricity produced.

4. Do I need any special tools or materials for building a power-generating turbine?

No special tools or materials are required for building a power-generating turbine with an unmodified motor. However, you may need basic tools such as pliers, screwdrivers, and wire cutters. The materials needed include a motor, a turbine, a magnet, a coil of wire, and a base to mount the turbine on.

5. Are there any safety concerns when building a power-generating turbine with an unmodified motor?

As with any electrical project, there are safety concerns to be aware of when building a power-generating turbine. Make sure to follow all safety precautions and wear protective gear when necessary. It is also important to properly insulate and secure all electrical connections to avoid any potential hazards.

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