Tesla turbine question !!

[roineust]

Hello!

Here is a small Tesla turbine:

http://www.epicphysics.com/model-engine-kits/tesla-turbine-kit/

First of all, for some reason, he doesn't say how many PSI he puts in, to reach that 80-100K RPM goal.

Does anyone have a crude estimation of the PSI? Would it be in the area of 1-10 PSI or 10-20 PSI ? I saw other DIY style Tesla turbines on the web, that claim they use 20-40 PSI, so i guess that would be the range in this case as well, although somewhat a smaller turbine here?

Secondly, just from looking at the design and understanding the underlying principles of the Tesla turbine, does anyone know if it's possible to connect a small CD DC motor to the shaft and create the reverse operation? e.g. make the turbine act as a compressor?

If this is what will happen, when attaching a motor to the turbine, as is, with no changes at all, it will become a compressor, then my question is this:

Say the motor attached is as mentioned, a 50K RPM CD DC small motor. If he needed, say, 15 PSI, to create 50K RPM, does it mean that when i connect the 50K RPM motor, i will get back somewhere close to 15 PSI or much less?

Thanks a lot!

 

[HPost]

From what is seen on the video, the plastic pipe and the noise from the compressor would suggest that the pressure was no more than 8 Bar. Give or take little.

The turbine works on the principal of energy conservation, air pressure changing to velocity in the inlet of the turbine. Running the process backwards would not make a compressor. The turbine uses the boundary layer effect the turn the discs. If the pressure rises, the discs will just slip. You can generate pressure with it, but it won't be a compressor. Much the way a centrifugal pump works.

HPost CEng MIMechE

 

[MikeHalloran]

What do you mean by "CD DC motor" ?



Mike Halloran
Pembroke Pines, FL, USA

 

[roineust]

CD= compact disc
DC= direct current

 

[MikeHalloran]

Uh, yeah.
AFAIK, true DC motors have never been used in CD players.
The very first CD drives used cheap AC motors.
Fast CD drives use brushless DC motors, which are really three phase AC motors.
In neither case is the speed proportional to the supply voltage.
In neither case do the supply terminals produce DC when the motor shaft is backdriven.
Additionally, the bearings and rotating parts of CD drives are not designed for speeds of tens of thousands of revolutions per minute.



Mike Halloran
Pembroke Pines, FL, USA

 

[roineust]

Sorry, maybe i was misled when buying it, by being told it is a CD motor or maybe it is my mistake, regarding its origin, all the way. Anyway, i am almost confident, it runs more than 35K RPM.