This is from the site "How stuff works"
"During the tests, engineers from Allis-Chalmers grew concerned about both the mechanical efficiency of the turbines, as well as their ability to endure prolonged use. They found that the disks had distorted to a great extent and concluded that the turbine would have eventually failed."

"But Rice, an expert in fluid dynamics and the Tesla turbine, conducted a literature review of research as late as the 1990s and found that no modern version of Tesla's invention exceeded 30 to 40 percent efficiency.

This, more than anything, prevented the Tesla turbine from becoming more widely used."
http://auto.howstuffworks.com/tesla-turbine4.htm

Do others here agree that it is only 30-40% efficient?

If some say so then I say the design is not as efficient in what material or how its made to perform well. Since water going through a tube in your home hits the inner walls of the pipe, but the same with a Tesla turbine to hit the walls of the smooth disk and the pressure gives it its movement. I see people say they made Tesla turbine but they seem to go against the notion of having no resistance when they put holes in the disk for grip and traction, or blades... so it seems.

Quote

Modern multiple stage bladed turbines typically reach 60% - 70% efficiency, while large steam turbines often show turbine efficiency of over 90% in practice.

Source = http://en.wikipedia.org/wiki/Tesla_turbine
Apparently it depends on how close to the original design you are when you replicate his engines.

It is a big deal if it can reach 90% if you feel it can.

If it is efficient then in what way makes it efficient?

IMO, the genius in his designs lies in the smallness of the engines who can turn a stream of some fluid into a mechanical movement with very few losses along the way, like for instance the bladeless steam turbine shown there, http://en.wikipedia.org/wiki/Tesla_turbine
As opposed to having a relatively bulky "traditional" steam turbine, which has anything from 50% to a theoretically possible 64% efficiency grade, source = http://www.mpoweruk.com/steam_turbines.htm
But like in so many other similar cases, TPTB sees to it to supress this kind of technology, and other such superior technologies for that matter, so they'll never see the light of the day, it's 'only' in the homes of such enthusiasts as this forum's members that these machines are being built and kept alive

with new materials being much easily produced since 100 years ago it could fix manyof the issues it has back then.
Also wouldn't you think that it would be a good idea ti place it at the tap of a faucet since the water pressure will be the same with or without the turbine?

Also another turbine at the wasted drain but I feel the Tesla turbine would not work in the drain since it needs pressure. Which is the most wasted form of energy going down the drain.

Hello WSX
Telsa turbine is friction drive, very inefficient. 30% would be its maximum.

This may be increased if spiral grooved ? Such would give the water greater contact to apply its force.

It kind of does and does not make sense regarding friction for the excuse for efficiently.

True that it has friction since it does not push a propeller but needs to move with friction. The bearing would need a redesign from the traditional old ones as stated once to be replaced with magnetic bearing. The disk should not obstruct the flow of water at all. The only way it should move is through friction to hit the side of the disks, but as bad as that sounds that is that makes it efficient.

Since water passing through a regular tube it still has friction since the water touches every inch of the pipe's inner walls. Even if you use 100 straws with the same water width the friction would be over 100 times more but it would or maybe should have the same flow/pressure since it has no obstruction. But we do not say pipe are inefficient to transport water due to friction every inch of the way for miles length before it comes to your home. So the same can be said about the Tesla Turbine.

That's the beauty of it I think since it does not go against the flow to get it's power but goes with the flow and unlike regular devices it gets more efficient the faster it goes it seems.

Maybe it has its good and bad but would Tesla Lie about it? No its not in his nature. Can he be wrong? Maybe but usually he isn't.

So lets say it is hypothetically 33% inefficient for arguments sake. How how water flow/pressure loss is it when the water comes out of the turbine percentage wise? Also 33%? So if you put 3 Tesla turbines in a row how much of a loss of flow/pressure loss will it be? 99% to be at a complete stop?

It just does not seem it would be 99% loss of flow/pressure and if not then how many Tesla turbines would it take to make it the turbines be the most efficient until the water stops or stops moving Tesla turbines?

It just does not seem like a regular engine like a gas one where you can not reuse the sour of power.
That's how I assume it which I can be wrong, but I would like to hear another explanation.

He says it was documented in 1911 that it can be over 90% efficient

Despite I pointed some other flaws, the problem with the device is that if the disk spin very fast it will centrifuge anything from the center to the side, so would it be more efficient if the turbine started from the center?

Also should the center of the disk be empty? Some say say its impossible but powerful magnets can levitate the disks that way no friction and no obstruction.

Wouldn't the turbine be better if it was cone and the water enters in the center part of the cone sideways at the top. A pyramid turbine in a way. Just a silly thought and maybe a bad idea, but I am just saying.
Imagine a transmission that used a pyramid turbine to switch gears instead of gears. lol Maybe it can switch gears more efficiently but it might being going very fast nowhere. lol

   /-\--  <-- in from the side
  /---\
 /-----\
/-------\__ -->out from the side

Hello WSX

I agree, and in fact turbines do exist as you suggest.