Generator heads

From: Larry
Email: paladin_at_heart@yahoo.com
Category: Materials
Date: 11 Jan 2004
Time: 03:10:04

multi-stage turbines

From: G.D. Lay
Email: gregdlay@hotmail.com
Category: Theory
Date: 12 Jan 2004

Comments
Is anyone working on multi-stage, or "stacked" turbine units? In the pieces I've read, more power is delivered than from one turbine. This would be idea for automotive applications. Any hints or rumors?

Re: multi-stage turbines
From: RichardGideon
Email: spotteddogs@iwic.net
Category: Combustion
Date: 13 Jan 2004

Comments
D.G.Lay: Welcome to the challenging world of the Tesla turbine. Your question and those of the others here, who have been asking questions over the last couple months or so, are why I find this area so interesting. At a quick glance the turbine is a deceptively simple device, that is until you try to build one. You then find that there is precious little really good design data available. A little history here is probably a good way to show why this is so and why there is no easy answer to your question. 

Tesla developed the turbine around 1911 and was working with it until about 1922. In that time he built a number of models of different sizes. The biggest one had a 5 ft. diameter rotor, if I remember right and ran about 3600 RPM and produced 650 HP. But all his models were just engineering prototypes none of which ever became production units. Basically he was the new kid on the block trying to sell an unproven idea at the time when the piston steam engine was still king of the hill. As a result the turbine was never developed into a production unit and unfortunately because of this there is very little good design data available. Thus what I have been doing is experimenting with different design parameters to try and find out what works and what doesn't. 

The 5 FT. rotor was one of the last ones that Tesla designed and the manufacture pulled the plug on the project when they were not getting the results that they hoped for or what Tesla "claimed" for the turbine. Tesla blamed the companies engineers for not listening to him, the engineers blamed Tesla for not listening to them and the management of the company wanted Tesla to design the turbine to run on hot gas rather then steam. You get the picture. This was the last serious work that Tesla was reported to have done with the turbine. So what we have now is an area that is wide open for the experimenter to try new ideas and perhaps come up with a new power source. I know that this is not answer you were looking for but I hope it has been of some help. Sincerely Richard Gideon

Re: multi-stage turbines
From: Corbin Irvin
Email: Cajunjoe_here@yahoo.com
Category: Combustion
Date: 13 Jan 2004

Comments
You could just add more disks to the main turbine. That way it will be alot easier and lighter. To make it usable in automotive applications, you would have to supply the working gas to the turbine, and you might have to gear it down to work with existing transmissions. It would be interesting to see a boiler on the back of a Honda. luckily the turbine works more off the pressure of the fluid rather than the volume so you can used compressed air, liquefied air, or even better, design it as a turbojet and burn a fuel such as propane.

Re: multi-stage turbines
From: Bryan LaVelle
Email: bryan@lavelle.us
Category: Combustion
Date: 28 Jan 2004

Comments
Been reading a little about steam and I think I know where G.D . is going with this. I think if you just add more disks to the stack, you have to increase the amount of pressure going to the disks to maintain what you had before. But in steam engines there is the concept of multi expansion, i.e., using the same steam to do two or three times the work. It's more efficient. I've been wondering about this myself: would the pressure remain high enough after exiting the hot case of one enclosed turbine, to in turn be ported to the input of a second hot case, and perhaps even a third hot case. Seems to me that your thermal efficiency of heating the the working fluid goes way up that way, if it would work. Mind you, I'm not a steamer, but am very interested in learning more about it, to drive a TT.

Re: multi-stage turbines
From: Kenneth Herring
Email: rockindolphin@yahoo.com
Category: Combustion
Date: 27 Apr 2004

Comments
Unfortunately, my first attempt at building a bladeless turbine failed; I had to leave my set-up in the rotary table in a shop full of people for several days and I believe a handle got bumped against, and I haven't been able to get into a situation conducive to turbine building since... Therefore, what I am about to say is speculation, but it is my opinion that subsequent turbine stages will be smaller than the first, both in diameter and disc spacing, and then each stage will have it's own throttling valve as Tesla designed so that the pressure in each stage will enter into the rotors at the highest possible velocity for the given working pressure. Each subsequent stage will choke-down, or create a backpressure against the previous stage, so a balance in individual throttle valve settings will have to be found so that they all work efficiently in concert, I would believe. Tesla said it could be done, but to my knowledge no details were given towards that end.

Re: multi-stage turbines
From: Techno
Email: t
Category: Combustion
Date: 27 Sep 2004

Comments
I think a staged turbine would follow the same method already used on other turbines. High pressure sections are small in diameter and have a very small blade area. As the steam or force is expended you need more diameter and more blade to scavenge the lesser energy. The steam turbines at work. The 1st HP section has a diameter of about 2' and the blades are only about 2" long. This steam is then sent back to the boiler. Its called extraction steam. The next stage gets normal steam and this is larger in dia. and so on. The low pressure- LP is about6' in diameter and the blades are 2'? The steam exits this last stage directly into the condenser, where it instantly changes to water. This produces a vacuum on the turbine and there are vacuum pumps to assist this if it is going too high, I think they try for -13psi or so. This is what an exhauster would do. Place a vacuum on the turbine sections. The thing runs on 1,000* and 1,000 psi steam. If water condenses in the turbine it eats the blades. I saw one where the leading edge looked like a sponge from moisture hitting it. The Tesla turbine is supposed to be able to take that. Condense internally.

Re: multi-stage turbines
From: Yuri
Email: bent-animator@postmark.net
Category: Combustion
Date: 30 Sep 2004

Perpetual Motion a possibility ? *hrmm*

From: Alan Cresswell
Email: Alan@acresswell.fsnet.co.uk
Category: Other
Date: 18 Jan 2004

Tesla Turbine Vacuum Applications

From: Jeff
Email: whiplash@byu.net
Category: Theory
Date: 20 Jan 2004

Comments
Just stumbled onto this site (for FREE no less....beautiful) and I thought I would ask a question that someone may know the answer to. I am currently working on a vacuum application based on information that I have read regarding compression ratios and compression limits. I read that there was a claim that the Tesla turbine generated essentially 6 atm of pressure. In my vacuum application that would certainly fall within the ball park. I really need at a minimum a compression factor of 10 but I will take more if that is possible. As stated, I designed a Tesla based on the Tesla Disc Turbine plans and modified it for my application. We ran it for the first time tonight. I was a little disappointed as the alternative is not very desirable. At any rate, I put around ~40psi of house gas into the inlet of the disks (inlet being the edge of the disk bundle....using the Tesla first as a generator) and was able to measure ~23,000 rpms with no load. Not bad I thought. Then we hooked up a DC motor and tried to run it in vacuum mode. These results were less than desirable. At around 8000 rpms we were only getting a 2 torr change in pressure. So, of course, we decided to apply more voltage to the motor and drive it to 16,000 rpms and then measured an 8 Torr change in pressure. Clearly with this limited data you can see that it looks like a quadriatic function of rotation speed (or something like that). We could not drive the DC motor faster than that so I sat down very disappointed. We started thinking about possible reasons and I would like to share them with you and hopefully generate some response as to whether I am smoking something illegal or that I may be headed in the right direction. 1) There is about a 0.30" gap between the two end disks 'runners' of the disk stack and the housing wall. Further, there is a 0.05" space between the OD of the disks and the ID of the housing. My conjecture is that this was a significant design flaw on my part given that there could be significant blow-by between the inlet of the vacuum at the center of the shaft and the exhaust port. Is this a reasonable assumption? If so, how does one seal off this blow-by without touching a surface which is spinning at over 20,000 rpms? 2) The last disk (furthest away from the opening) on my engine (vacuum) has the openings the same as all the other ones. I am also thinking that this is why I don't get any more significant air flow when I use this as a blower. Again, blow-by in the back of the housing due to a build up of pressure at the periphery of the plates that has no clear path to escape. One final question....How have you attached your disk stacks together? I am not happy with my solution which is to make the two outside disks thicker than the other to allow a threaded hole to be tapped and use a flat head #4 screw to hold everything together. Thank you in advance for anyone who can shed light on my problems. I don't want to desert this solution for this application.

Re: Tesla Turbine Vacuum Applications
From: Corbin Irvin
Email:
Category: Combustion

Comments
Well, You coud try mand gear the motor by putting a small pulley on the trubine shaft and a larger one on the motor. It will take more power to drive it, but it will run much faster.

Re: Tesla Turbine Vacuum Applications
From: RichardGideon
Email: spotteddogs@iwic.net
Category: Member project
Date: 21 Jan 2004

Comments
JEFF: Welcome to this site. When building a turbine engine the rotor wants to fit into a nice round hole in the case/housing. But when building a pump the hole in the case should have shape or contour of that of a conventional centrifugal pump. Also to help prevent leakage you will what to keep the gap between the rotor and the sidewalls to an absolute minimum. To further prevent leakage this surface could take the form of a labyrinth type of seal. While this type of seal can be a pain to machine in will definitely not wear out. There is nothing wrong with the way you are holding the discs together. I am assuming though that you are using spacers (washers) on the screws between the discs. Please keep all of us informed of your results.

Re: Tesla Turbine Vacuum Applications
From: Jeff
Email: whiplash@byu.net
Category: Combustion
Date: 21 Jan 2004

Comments
Richard, Thanks for the feedback. I have recently read about the advantages of vortex when the gas is escaping the edges of the discs. Currently, I don't have that in our little R&D unit so I will just have to make due until the next design turn. At any rate, I am playing around with disc spacing and am building up another shaft. I just don't like the way I am clamping the plates together. I think I am going to try and use my existing press fit collar and just go with a washer in between each stage of a particular thickness and then rely on the press fit to keep everything from slipping. I have opened up some hard disk drives that use this same principle and I can't imagine that any slippage would be acceptable. I just want to minimize and machining involved to keep the costs down. I will keep you informed.

Re: Tesla Turbine Vacuum Applications
From: Kenneth Herring
Email: rockindolphin@yahoo.com
Category: Combustion

Comments
I have an idea for a possible serious increase in torque and horsepower for the turbine, using a primary as a compressor, directly linked to the secondary with a ramjet style inlet where fuel may be injected and ignited you could develop some tremendous thrust for spooling up and driving the turbine, and for additional mass you could inject de-mineralized water to increase the mass of the air flowing over the turbine for faster spooling up and maybe even as like a temporary boost under heavy load conditions. I saw this work with jets loaded with very heavy loads, and they would inject the water vapor and get a massive increase in their takeoff ability. Anyone with ideas as to if this would be an efficient engine?

Re: Idea for second stage tesla turbine
From: C. Wayne Lammers
Email: mlammers@midsouth.rr.com
Category: Combustion
Date: 23 May 2004

HomeMade Waste Oil Burner for the Flash Boiler Project

From: Herschel
Email: HJLRULZ@aol.com
Category: Member project
Date: 22 Jan 2004

Forecasting...

From: Bryan LaVelle
Email: bryan@lavelle.us
Category: Theory
Date: 28 Jan 2004

Comments
Hi there, Does anyone here know how to forecast the expected RPM of a TT , given the size and number of turbine disks at a given pressure of steam? Also, given that, how to predict how many pounds of steam per horse power/hour one might need, to aid in boiler design. I see that larger TT have slower RPMs. So, my question is this: Say a 10 inch, 25 disk TT @ 125 PSI gives 18000 RPM, what would the expected result in RPMs be from doubling the number of disks but keeping the pressure constant? My thought is that the horse power would double (approximately) and the RPMs would be reduced. Your thoughts? Bryan

Re: Forecasting...
From: Bryan LaVelle
Email: bryan@lavelle.us
Category: Other
Date: 05 Feb 2004

Comments
Continued reading of the forum archives have answered many of my questions. I'm still not sure how to calculate steam needed, but that may be too obscure a thing to identify, unless one can closely determine in advance what the efficiency in the steam generating portion of the boiler is. Looks like the direction I want to head is a 10" turbine with 6 disks, to get in the neighborhood of 20HP, for off grid electric generation. I'm speculating I'd need about 800 lbs of steam per hour to drive that, approximately 40 1bs per HP per hour.

Re: Forecasting...
From: Ken Rieli
Email: ptbc@phoenixnavigation.com
Category: Theory
Date: 17 Feb 2004

Turbine disk width

From: Larry
Email: paladin_at_heart@sbcglobal.net
Category: Materials
Date: 02 Feb 2004

Comments
I don't recall seeing anything on the width of the disk anywhere, and I was wanting to know how wide do they need to be to be stable enough, but also allow for the maximum number of disk. also is there a ratio of total width to disk size before you start losing efficiency from the expansion of the steam

Re: Turbine disk width
From: Ken Rieli
Email: ptbc@phoenixnavigation.com
Category: Efficiency
Date: 17 Feb 2004

Pyrocatalyic burner

From: Bryan LaVelle
Email: bryan@lavelle.us
Category: Combustion
Date: 04 Feb 2004

Tesla turbine

From: Håken Hveem
Email: lc8ubt(a)frisurf.no
Category: OtherDate: 11 Feb 2004

CDs for rotors

From: Nick Evans
Email: nick_g_evans@hotmail.com
Category: Member project
Date: 11 Feb 2004

Comments
I surprisingly found a couple of posts about using CDs for rotors. I thought it was a good idea when I first thought of it, and I guess it has worked for a couple of people. Are there any others that have done this? Here is one archived post I found: Has anyone experimented with using 'junk mail' CD disks for low-temperature Tesla rotors? Finally we have a use for AOL! 

Re: CDs for rotors
From: Nick Evans
Email: nick_g_evans@hotmail.com
Category: Member project
Date: 16 Feb 2004

Comments
OK, you bunch of weinies, nobody answered, so I went ahead and made a pump out of CDs. This stuff's fun! I used five CDs attached to each other by glue and washers, drilled some holes through four of the five CDs, and glued a nail to the middle. I stuck this in my dremel and put it face down, middle vents up, into that plastic CD cover thing that comes with stacks of blanks, and spun it around. Sure enough, it blew some air staight up back at me. :)

Re: CDs for rotors
From: Ken Rieli
Email: ptbc@phoenixnavigation.com
Category: Member project
Date: 17 Feb 2004

Comments
We have designed and built a small educational unit using two CD's and low pressure (10 psi) compressed air. Works great for initial tests.

Re: CDs for rotors
From: Richard
Email:
Category: Combustion
Date: 18 Feb 2004

Tesla's Turbine

From: Stewart Bartlett
Email: nagaloo@netscape.net
Category: Applications
Date: 06 Mar 2004