Comments on: Tesla turbines for fun and profit

By: Granville Discher

Granville Discher — Tue, 23 Feb 2010 03:16:36 +0000

Amazing, outstanding info. This blog is really cool. I bookmarked this and may come back again.

By: Adam

Adam — Sun, 05 Jul 2009 01:49:24 +0000

Just a little hint, don’t wear gloves and use power tools,

if that motor catches skin, no problem… you can pull away…

but if the motor catches the glove it will tear your hand apart…

By: slade

slade — Mon, 09 Mar 2009 22:44:30 +0000

I’ve been following Tesla’s work for a few years now and I would like to say that EVERYONE uses his devices on a daily basis. He came up with the Polyphase AC system we use as a nation to send power from a generating station(Dam’s, nuclear, coal, solar, wind, etc.) uses a transformer that he and his financial backer and inventor Westinghouse purchased from a french inventor and improved on. After the power is stepped up to a very high voltage it is transmitted along power lines and then stepped back down to useable levels. TESLA is responsible for more than anyone wants to admit. He got us the AC system and fought Edison and his DC power generation system that would require generating machines every few miles. He proved the existence of the rotating magnetic field used in pretty much all DC motors to this day. The brushless DC motor. Also did a lot of work in the fields of radar, wireless power transmission, wireless communication, flourescent lighting(He made lights that didn’t need to be plugged in!), he created his own oscillators(said to almost shake a building frame of a skyscraper in NY to the ground from repeated Harmonics), and he designed the first generator used on Niagra Falls. He has been known to say that the Tesla Turbine was his best invention. So anyway, you never hear about Tesla in School it’s always Edison… But Tesla was undoubtably the best Electrical engineer of his time.

By: rick crammond

rick crammond — Mon, 03 Nov 2008 05:05:59 +0000

Hey ronnie,
Good comments…

I should make it clear that I consider the projects I do with the Tesla CD Turbine to be temporary. After all, it is CD’s, CD Cakebox and spindle, etc being used. I blew the top off one last week.(movie to come, hehe)

On air pressure this turbine needs 15,000 rpm to begin to make decent torque…30,000 is a good working rpm. The turbine can be geared down for more torque at less rpm, or a high-speed alternator can be fitted.

Unfortunately my materials (magnets, CD discs, glue) will explode at any more than 15,000 rpm. So currently the turbine needs to be run in an inefficient rpm range. It can’t get into the range of power it wants to without modification, but it does hint at the potential in a fun way.

The noise really isn’t an issue. Usually, commercial Tesla turbines get quieter with speed, especially above 20,000 rpm. They run much quieter than bladed turbines.

And they can take the abuse of dirty fuels, pressure surges, etc in commercial applications much better than bladed turbines. The Tesla Turbine is the only turbine type able to run on 100% biomass combustion products.

“Air tools are common” about sums it up…My CD turbine would have less efficiency and can’t compete…except in fun factor!!

By: Ronnie

Ronnie — Sat, 01 Nov 2008 14:38:18 +0000

To my understanding this doesn’t seem like a good way to power anything but an proof of concept/art car rick since it looks like all of this turbine’s power is made at extremely high RPMs, which would require high-strength materials and make a lot of noise compared to other engines.

How about for air tools though? Air compressors are already fairly common, and if your turbine were many layers deep it might be able to put enough torque out for some air tools, though I’m not sure about the efficiency compared to normal air tool mechanisms.

By: rick crammond

rick crammond — Sat, 01 Nov 2008 06:10:47 +0000

I have lots of thoughts. Hard to find folks to sponsor them!
I’d drive a Tesla Turbine powered vehicle if I could afford to build it.

Plexi is no good for discs…it will creep and shatter similar to the polycarbonate CD and DVD discs. Aluminum will fatigue crack.

Special stainless steel has been the traditional Tesla Turbine disc material, except for Tesla who used German silver.

I’m looking at new forms of nanocarbon for discs that are far stronger and much lighter than steel, yet can take the heat of a true turbine on fuel. (could someone please send me some??)

The problem is that a shaft, bearings, seals and tough case are usually required. My magnetically-coupled Tesla CD Turbine has none of those things!

By: veegeezee

veegeezee — Fri, 31 Oct 2008 06:10:19 +0000

neat stuff, rick

any thoughts of trying the tesla turbine with more “conventional” materials, like plexi or aluminum? i just ran across a similar project that used hard drive platters, too, though not to such creative ends.

By: rick crammond

rick crammond — Fri, 31 Oct 2008 03:22:10 +0000

meznak good point…
unfortunately, Tesla’s work is invisible to most folks.

For example, lots of people over the last century have spent time looking at a speedometer. It’s a very important part of our lives, judging by the speeding ticket revenues. Who would have stopped to consider that it was Tesla who invented the traditional (pre-digital) speedometer? (US patent #1274816)

The auto speedometer is based on the same principle as the original Tesla Turbine and this Tesla CD Turbine…adhesion of moving fluid to a surface.

By: meznak

meznak — Thu, 30 Oct 2008 17:54:27 +0000

@anthony

i don’t know about you, but i see tesla’s work almost everywhere i look.. i’ll bet you use dc motors on a daily basis…

By: Haku

Haku — Thu, 30 Oct 2008 16:18:31 +0000

Is it just me or does he look somewhat like an evil movie bad guy with his black leather gloves and black clothing whilst cutting into an innocent pumpkin with a spinning blade?

Maybe I’ve just been watching too much Space:1999…

By: rick crammond

rick crammond — Thu, 30 Oct 2008 10:08:45 +0000

It’s my tinfoil safety toque. It and the safety glasses protected me well, when my trusty little turbine blew up at the dining room table a couple of days ago. No humans were harmed. A few small spiders did drown during the ensuing tsunami.

Fortunately I did get a video of it! (minus the spiders)

By: jim

jim — Thu, 30 Oct 2008 08:21:45 +0000

you have to love the way the blender guy is wearing goggles and a tinfoil hat whilst making his organic smoothie.

By: rick crammond

rick crammond — Thu, 30 Oct 2008 06:13:51 +0000

Good comments, anthony and veegeezee!

The correct term we are looking for is adhesion. Tesla determined after some consideration early in his life that it was not friction, but the viscosity and adhesion of the boundary layer between the closely spaced discs that supplied the force from the fluid.

Folks might look at some new ideas in this turbine as well…like attaching magnets to the discs makes a rotating magnetic field which can be very useful. And this turbine has no bearings, no rotating shaft or shaft seals. That’s different!

By: veegeezee

veegeezee — Thu, 30 Oct 2008 05:00:07 +0000

anthony – the writeup is fine, i think. another name for boundary layer drag is ‘skin friction’, and the reason a mirror polish is more effective is that it produces less normal (or transverse) velocity, which is a much better condition for transmission of fluid shear forces than a rough surface, where you might have turbulent boundary layers with large wall normal velocities near the surface.

i guess in an engineering sense, ‘friction’ isn’t the word we’d usually use for drag or shear forces, but it makes sense.

By: anthony

anthony — Thu, 30 Oct 2008 02:50:18 +0000

neat. i don’t normally see much from tesla other than the tesla coil, and these turbines have a lot of great applications if you can get over the absurdly high rpms (and give it a real power source).

now there is a slight inaccuracy in your writeup: the tesla turbine does not use friction to move, but the boundary effect. essentially, any time a fluid moves over a surface, there is a layer of fluid that does not move, which the rest of the fluid tries to drag along, resulting in drag.

the way you can prove this is to build two identical turbines, and give one set of blades a mirror polish, and the other set of blades a matte finish (rougher surface=more friction). logically, if friction between the fluid and the blade drives it, the rougher finish will generate more friction and better performance. in reality, though, the smooth blades get better performance.

as for “useful”: since when has hackaday been “useful”? fun, interesting…certainly amusing, but rarely are the projects created for any reason other than “because i want to and i will have fun doing so”…which is why we have nasa.