Gas (Tesla) Turbine started

[Nick]

More progress.
after long and productive conversations with Rossco,Ive decided to get a little more realistic with the Nozzle design.
The current design didnt allow for any fixed air supply and most of my air was blowing back out of the hole!, thats clearly no good for measuring anything so ive redesigned the 3 inner laminations of the turbine so that an 8mm bar can fit into a hole running front to back which just intersects with the turbine cavity
The 8mm bar has a 1/4 section milled away and is hollow, air being fed down the shaft exits through the milled away section and then into the turbine cavity, the nozzle is adjustable by virtue of turning the bar which opens or closes the gap through which air can pass onto the discs.
I was also pleased on two counts to note that by specifying a hole dia of 8.05mm the 8mm ground steel bar is a perfect tight sliding fit, like a tight reamed hole 1. that the oversize "guess-timate" was right and 2. that the mill happily makes such tiny incremental changes possible.
I'll post a pic when its done anyway.
Cheers

Nick

[Nick]

pic as promised showing new turbine housing and variable geometry nozzle.

Nick

[Mike Everman]

Tricky, Nick!

[matt512s]

Hi Nick:
Beautiful build! I just wrote to clarify that the combustor patent I
referenced is NOT a pulse combustor. It is a miniature liquid-fueled
combustion chamber in which the fuel is injected and forms a film
on the interior walls. This serves to help vaporize the fuel and confine
the combustion to the interior of the combustor. In addition, the
walls of the combustor tube are claimed to become no hotter than
the boiling point of the fuel! The largest of these is a tube one cm.
in diameter and 3-4 cm. long and claims to have an output of 10 Kw.
One question: Could you give me some details or a link to the
pulsejet pressure tap experiment? My first idea for powering my
turbine sounds like just such an arrangement.
Best wishes
Matt

[Graham C. Williams]

Hi Matt.
The pressure tap experiment is not written up at this forum. It happened as part of the mini meet, when Mike Evermann came over on his way to Zurich. Steve Wallington was running his large Chinese (designed by Eric I think) on gas and liquid fuel. At some point Steve attached a small-bore pipe, I guess 1 to 2mm I.D. by 40 to 50cm long, to a lug on the side of the combustion chamber. This lug was located about half way along the CC.
Perhaps Steve can fill in the details.

Graham.

[Nick]

Just a quick update,

Been monster busy with work and the new Reynst pot (more of that on another thread later) so work on the GT Tesla has seriously lapsed.
However i have had the good fortune to meet up with a real tesla expert at the Model Engineering show so when i come back from my motorbike Austria in early October experiments will begin again.
Incidentally an article in Model Engineer has been published about a tiny Tesla steam turbine -30mm dia!!!! powering a 4 meter long model train at a scale speed of 170kph !!! on a tiny boiler running at 4 bar. Measurements of power have also been published in the article which give the power output at 30000rpm of 1.7watts. Not uge inkow but the turbine is smaller than a penny and could be made significantly more efficent, the construction method although effective, uses up a large area of the discs for holding them together, plus the centre hole or hub is too big really, i calculate that the actual effective size is a mere 6mm!!! dia.
By making few changes the effective disc area could be 13mm or more greatly increasing the torque.
Anyway more later

Nick

[Kakeman]

That tesla turbine is very interessing.
Is it possible to build whery efficient, light and powerful turboshaft with tesla turbines? 300KW and weight.. under 100Kg?
useing titanium would enable higher RPMs(light and strong) and higher temperature.
Would engine with second turbine give better efficienty and power?
How about flow rate on tesla turbine compared to normal axal turbine with same power?

[Nick]

there is very little hard fact published about Tesla's unfortunately but there is one guy who i know is an expert in this field, Kev Chappell. I will forward on your questions to him and see if he can give you any answers ( i certainly cant). Kev is, like me a member of the Gas Turbine Builders Association, it might be worth while checking the GTBA website out if you are serious about it?

I know some really serious work is being done by Kev on sorting out the real hard facts about Teslas, some of the results may be available next year.?

regards

Nick

[Kakeman]

im just intressed, not very seriousy. I dont even have money or machines to do anything.

[tufty]

I know some really serious work is being done by Kev on sorting out the real hard facts about Teslas, some of the results may be available next year.

Good. It would be nice to see some real figures. Although the turbine itself has a number of useful looking properties (not least of which are ease of manufacture and robustness compared to a "traditional" turbine), the majority of people who seem to have played with them seem to be the same sort of people who believe "Brown's Gas" has some sort of magical properties...

Simon

[Nick]

LOL !

Browns gas yes know what you mean :-)

No seriously though i can say that from what ive done and from Kev has revealed Teslas are very good at producing pressure but not so much volume. however the more discs you have the more volume, so i reckon that can be over come.

Cheers
Nick

[Graham C. Williams]

LOL !

Browns gas yes know what you mean :-)
Cheers
Nick

And now we have : Hyper-Gas

Ho Ho.
Seasons greetings
Graham.

[Kakeman]

is there any ratios or formulas for tesla turbine desing?

[Kakeman]

i wound bladeless gas turbine from teba site

[Nick]

is there any ratios or formulas for tesla turbine desing?

thats alot of what the research that Kev is trying to find out but as far as tubines go almost any dia will work. I have a 25mm dia turbine that goes well.
if you stick to the discs less than 1mm apart that will stand you in good stead, a rough rule of thumb
5-12 discs, 0.6-0.8mm apart , try and direct the air or steam in between the discs and not around the ends of the turbine, this will reduce gap losses.
Experiment with unwanted CD's .

Let us all know how you get on.

Nick