Having a bit of Trouble with Tesla Turbine

[JoeFin]

I built this Tesla turbine for my kids Science project and I'm having a bit of trouble with the nozzle. I'm 95% complete and would like to wrap this thing up and was hoping you guys could give me some ideas and where to go with this.



I realize for an Air Powered Tesla Turbine, at .125" spacing the Rotor Disk are spaced very far apart. Also constructed completely from Al. and SS. the Turbine rotor is pretty heavy and takes quite a bit of force to get going. How ever I've outfitted the little guy with a good set of bearings and once it gets moving it is capable of some pretty high RPMs



So far most of the test have been run using my Blow gun. I fashioned a nozzle with a 5.200" radius to match the outer dimensions of the stator housing and a series of 3/16 holes into the .500" manifold. I even used a nice cork gasket to ensure a proper seal, but when I apply my little nozzle it doesn't achieve squat for RPMs.



Any Ideas ....

I've all but given up on this nossel I built and am willing to try a whole new approach. The Turbine is constructed completely from Al. and SS and I would like to stay with those materials

[Black_Moons]

Well, One thing to consider is that when you use a blow gun, even a few inchs away, it picks up a LOT of ambiant air and moves it too.

Iv used a blowgun to inflate kiddy pools and such, And when you take the gun outside of the inflate opening about 2" it inflates about 4x faster!

Also with just one jet, you get massive air speed/flow. With 8 large jets, you need some serious SFM and pressure.

[JoeFin]

Also with just one jet, you get massive air speed/flow. With 8 large jets, you need some serious SFM and pressure.

Well perhaps that is where I am missing the point

Granted the air gun will produce significant airspeed, but that is only from 1 tiny < 1/16" orifice. The nozzle I constructed used 7ea - 3/16" orifices with a 1/2 manifold. The airspeed was greatly reduced but the volume was significantly increased.

Additionally - isn't the Tessla Turbine working on the premise the stator housing will pressurize to some extent as the gases work their way to the low pressure zone at the center of the stator. Regardless of the Density the gases must overcome centrifugal force to find their way into the low pressure zone at the center of the stator

I'm just asking cause I don't know

[TGTool]

I'm no expert on the Tesla turbine so take any advice with that in mind. However, my understanding of the operating principles are that the plates have to be close enough together that the surface friction comes into play. In other words, the volume of air entering compared to the area available for exit has to present enough resistance (friction) to pull the disks as the air moves toward the center exit. The first thought would be reducing the 1/8" between disks. Otherwise you have to pump a much higher volume in to develop the inlet pressure that makes it viable.

[gary350]

It looks like you have 7 air holes the cross sectional area of those 7 holes should be = to the cross sectional area of the incoming air line.

The area between the rotor plates needs to be equal to or a little less than the area of the incoming air lines.

Looking at the photo I think you need to remove about 10 of those rotor plates for it to work. Do the math calculations to find out.

[JoeFin]

However, my understanding of the operating principles are that the plates have to be close enough together that the surface friction comes into play.

Not to contradict ...

I saw in Tesla's original patent application he claimed his turbine would work equally well with Air, Steam, or Water. Also surmising from from a paper on Stanford.edu website comparing rotor diameter, and spacing, "Bigger is Better and Closer is Best"

They tested different diameters (6" - 12") and spacing as close as .020" and produced over 22 Hp from 12" diameter disk with .020" spacers - but all those test were conducted with AIR

If the Tesla Turbine was constructed to be powered by Steam wouldn't the spacing need to be increased to accommodate the increased density of the gas

BTW: Here is the data from the test at Stanford - http://www.stanford.edu/~hydrobay/lo...urbtorque.data

[Jaakko Fagerlund]

I would decrease the spacing a lot and add more air, that 1/8" spacing is just very much.

[Jaakko Fagerlund]

Not to contradict ...

I saw in Tesla's original patent application he claimed his turbine would work equally well with Air, Steam, or Water. Also surmising from from a paper on Stanford.edu website comparing rotor diameter, and spacing, "Bigger is Better and Closer is Best"

They tested different diameters (6" - 12") and spacing as close as .020" and produced over 22 Hp from 12" diameter disk with .020" spacers - but all those test were conducted with AIR

If the Tesla Turbine was constructed to be powered by Steam wouldn't the spacing need to be increased to accommodate the increased density of the gas

BTW: Here is the data from the test at Stanford - http://www.stanford.edu/~hydrobay/lo...urbtorque.data

Actually for steam the turbine wants smaller space between the plates (what I remember from reading Wikipedia about this).

TGTool, the turbine doesn't work on surface friction.

[japcas]

Neat looking project so far. I hope you get it running.

I've been out of school for a pretty long while but aren't the kids supposed to build their project? I'm not up on the rules and don't mean any disrespect but it kind of reminds me of the pine wood derby races that the parents have, I mean, the kids have.

[The Artful Bodger]

Hmmmmm..... have you actually built a low pressure high volumne Tesla turbine? Just for interest sake give it a test with a vacuum cleaner on 'blow'.