Modified Wind turbine

[Jay64]

I'm trying to work on some options for collecting bi-directional wind power coming through a tube. I want my prop to always spin in the same direction. The problem is that the wind will be alternating directions in and out of the tube. With a regular prop, this has the potential of spinning the prop in both directions upsetting the power generation. My first thought was to have some type of cupped system, so that the dish will always catch the air and the air will go around the other side.
Something like this.

7rotorassembled.jpg (66.32 KiB) Viewed 846 times

Another thought was to have a prop made with aerodynamic foils, like an airplane wing, for blades. That way no matter which direction the wind was coming at it, it would always spin in the same direction. I don't have a pic of this idea.

Does anyone have any thoughts on either options, or perhaps some other ideas that might work.

[Hillhater]

Its called a vertical axis wind turbine..

[Jay64]

But it needs to fit in a tube. The wind is going to be blowing up and down in a tube.

[jonescg]

Jay, if I recall, some guys were harnessing wave power by running mono-directional turbines in tubes. When a wave rises, the water level goes up and forces the air past. When the wave returns, the water level drops and the turbine blades switch direction. Outright power takes a hit, but you get two blows of the turbine instead of one. I'll try to find an image...

[itchynackers]

I saw that episode. If memory serves, it was Planet Mechanics and their Surf Power episode.

Edit: Here is the link to the full episode... http://www.youtube.com/watch?v=pAxBzI6DEkA

Starting at 36:00 minutes they are discussing the turbine. Eventually they decide on a Wells turbine which spins the same direction regardless of wind direction.

[Jay64]

Jones, actually, that is what we are trying to do, capture wave energy. I'm trying to get the blades from switching direction, but still capture the wind as the waves drop. Especially since these are going to be smaller waves in rapid succession, I just want the blades to continue to spin in the same direction the whole time. I can modify the whole outfit to accept different setups if need be, but a tube would be the easiest to get started and get data with. We are going to be stepping the volume of the tube down a lot to increase the velocity of the moving air. But I was also thinking that we could do more of a slot to do something like the VAT shown by hillhater, but laying it on it's side. I'm also thinking of a possible, easy to actually make, version would be to do the VAT style using PVC pipe cut in half long ways to make the cups. If I go that type of route I would definitely have to change the collector setup, and make it a decreasing volume rectangle box rather than a pipe.

[Jay64]

Ah, I didn't know a name for it. Thanks. I will search out Wells turbine.

[jimisbell]

To solve the problem, why not a bi directional valve at the input to the tube that flops to one side for one flow and the other side for the reverse flow then duct the flow from either side to the propper end of the turbine?

[Jay64]

Kinda seems like more work.

[liveforphysics]

It was great to see you at the races this weekend Jay.


This site has a bunch of info about wave generation, and various methods of getting it done.

http://www.eepe.murdoch.edu.au/resource ... index.html

[Jay64]

Luke, it was cool hanging out w you guys too. Did zero take 2nd and 3rd in race 2 as well?