Bladeless Gas Turbine/Jet Engine

[LeanMixture]

I am building a gas turbine engine that uses two stages of Tesla turbines and vortex tubes as combustion chambers.

I already built the core of the engine which was the most difficult part because I wanted it to be smooth and fit tight without any bolts or rivets so nothing interrupts the air flow. I tested it by forcing compressed air at 20 PSI and it looked promising in terms of high rotation speed and it multiplies the air output. Hopefully by the next month I can run it on propane after I install the igniters and so on there are still some parts to build.

All comments and constructive criticism are much appreciated.

Michael Labib

[SuperCaviTationIstic]

Looks and sounds cool... any more pictures?

just curious as to what your intentions for the final output were. Direct thrust propulsion, coupled to a mechanical output for moving a vehicle, or as a driving force for a generator?

If you're interested in electrical generation, did you know there was a patent I think in the 1970s for ionizing the intake air to a vortex tube and it produces a charge separation in addition to the heat separation. Also, it would form 2 magnetic fields, one in the other, because if a charge separation happens between the inner and outer laminar flows, and they are both turning in the same direction, then their magnetic fields are in opposite directions, thus forming a toroidal magnetic field, but not the ring type most people associate with a toroidal magnetic field. I would add a capacitor plate on the outside of each output tube too, linked to the opposite end tube, to help keep the charge separation up.

[LeanMixture]

Sounds interesting thank you for the input. My initial plan is to use the mechanical power for power generation and then install a slightly modified GEET system to enable me to run it on any hydrocarbon fuel including used car oil. However I was told if I use it for propulsion on a go cart or something similar it will draw more attention to the concept so more people would build similar devices if mine proved to be successful.

The purpose of using vortex tubes as combustion chambers is to confine the flame in the inner vortex so it concentrate the heat in the center without heating up the walls which makes it possible to use inexpensive alloys for construction and become more efficient in terms of heat loses. I attached more pictures.

Michael Labib

[gene gene]

Hi Michael, Good to see you here. Thanks for the pictures, any more?
Gene

[wayne.ct]

Gas flow ?

Interesting. I am curious about the flow of compressed air/combustion gas through your design. I am having a bit of a time visuallizing how this works. Perhaps you could supply a diagram? Thanks....

[LeanMixture]

Interesting. I am curious about the flow of compressed air/combustion gas through your design. I am having a bit of a time visuallizing how this works. Perhaps you could supply a diagram? Thanks....

The first stage Tesla turbine takes the surrounding air push it through the Vortex tube and then fuel is mixed and burned in it and then the expanding mixture is fed to the second stage Tesla turbine which is connected to the first stage by a shaft it is simple but the hard part to built is the core because I wanted to make it free of bolts and rivets so nothing inturrpts the air flow.

[LeanMixture]

Hi Michael, Good to see you here. Thanks for the pictures, any more?
Gene

Thanks Gene, I will try to show a vedio of it while being tested by compressed air and show other components before I start building the rest because it will be covered. The thing is I do not have a copressor so I have to take it out to make the vedio.

Michael

[LeanMixture]

Update

Hello everybody, Ok my first prototype was a failure but a great deal has been learned. I simply replaced the compressor and turbine stages by sets of bladeless discs and this doesn’t work for two reasons:
1- In the compressor stage Tesla turbines don’t provide enough compression to sustain combustion.
2- In the turbine stage due to the fact that the discs are thin they don’t withstand heat and warp rapidly.
However I decided not to stop here so I built a second prototype with one set of 10 discs separated in the middle where fuel is injected via a hollow rotating shaft so the top 5 discs pull the air then fuel is injected in the hollow shaft then they mix at the outer rim of the turbine and ignited the expanding gases will be forced inward to the lower stack of 5 discs to rotate faster and so on.
I know in the second prototype I didn’t tackle the issue of warping discs under heat but I said to myself if it works I can replace the lower stack with some exotic material that can withstand the heat.
Unfortunately that also didn’t work. However I think this could work if made on a larger scale but my current interest is to make a small portable turboshaft to power a small generator or a motorcycle and also I do not have the funds to work further on this design.
Finally some good news:
I learned more about Tesla turbines and I built a third prototype that is completely different and this one actually work and now I call it a gas accelerator. I will talk about it later.
Attached are some pictures of the rotor assembly in my second prototype.
Michael

[Allcanadian]

@LeanMixture
As luck would have it I have quite a few years of R&D with micro-turbines and built a few turbine simulators to speed up the calculations. If you have any issues or questions you can PM me, excellent build.

The issue your having is "match point", this is when the work required by the compressor is equal to the work generated by the gas turbine. As well the compressor and gas turbine must have an equal mass rate of flow, calculated by tip velocity minus slip in your case times total area between sections.

I like to think of it this way, this is a constant pressure machine and the compressor must hold the internal working pressure while adding combustion air. The combustor heats this air but should not produce a pressure rise nor drop in pressure, it is neutral. The gas turbine must hold this internal pressure while extracting energy from the expansion of the hot gasses back to atmospheric conditions. The work here is not the pressure as it is constant throughout the machine, the work is due to the fact that working gas is hot and expands more in the gas section than it contracts in the compressor section while the mass rate of flow remains equal. This is not a pressure engine it is a heat engine.

You may also want to consider pre-whirl as I believe it is the most underrated addition that can be made to a gas turbine yet can be very effective.

Regards
AC

[LeanMixture]

@ AllCanadian

You are right pressure and mass flow pressure don’t play a key role here as it does in a conventional gas turbine or even in an internal combustion engine. I presume you have an idea about pulse jet engines in this type of engine it has a one way valve that allows the air to move in one direction at each cycle or pulse as it opens and closes due to the vacuum created in the tail pipe, now assume we can replace this valve with a Tesla turbine that is allowing the air to move in one direction and rotates due to the vacuum created in the tail pipe then you have a constant operation instead of pulses. The Tesla turbine here is not used for compression consider it a rotating valve trying to keep up with the speed of moving gases due to the adhesion effect on the bladeless discs.

[Allcanadian]

@LeanMixture

I have built a few experimental pulse jet engines and a pulse detonation engine as well. The pulse detonation engine fired once and I could hear it echo for some 20 seconds across town ... I never fired it again, lol. I was actually quite surprised I didn't blow out all the neighbors windows because the sound was horrific, it is unimaginable.

What your proposing sounds like an excellent idea and most people seldom if ever fully consider the inertial properties of a fluid. I had done a few experiments in this area from my research on Victor Schauberger. You know this may have another area of application as a simple variation of the micro-hydro ram pump. Conversion of a low head/low flow stream into an intermittent high velocity utilized by a Tesla turbine/generator acting as a valve. The "valve" is not downstream it is upstream as the inertia properties have no preference one way or the other.

I believe schauberger was using a similar effect with his vortex process, it was also a non-material one way valve which caused the flow to "choke" in one direction. Now imagine a valve which isn't actually a valve it is a gas and never wears out. Schauberger was a sly old fox and I believe he deserves more credit than he was ever given.


Regards
AC

[Mad Scientist]

Ah another crazy person working with the Tesla Turbine. Why this is such a simple device that anyone can whip one out in no time and start running stuff. Right? Why at a quick glance the turbine is such a deceptively simple device, this should be no problem, well that is until you actually try to build one. You then find that there is precious little really good design data available.

History shows us the reason, 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 real 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 done is to experiment 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 and what Tesla was “claimed” for the turbine. Tesla blamed the company’s 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. It has been awhile since I last worked with by turbines but here are some of the things that I found that you might find useful. Now bear in mind that all my testing was done with compressed air thus hot gas will undoubtedly perform differently.

The very first tests I did with my turbines (6” dia) was to try to determine optimum disc spacing. Using compressed air I found a spacing of .048 to.058 in. gave the highest speed. Of course with different fluids the spacing would be different. Ideally it wound be nice to have some way to adjust the spacing while the turbine is running, although this might be a bit tricky to do.

I have not done any experiments relating to disc smoothness. However from what I have read the flatter, the smoother, the more highly polished the disc is, the better it works.

All the drawings that I have seen of different rotor discs show great big gaping exhaust holes at the center of the rotor. These large holes obviously weaken the rotor. Naturally we do not want excessive back-pressure, but just how big an exhaust port is big enough?

To find out I made a cap to go over the exhaust of my turbine. In it I drilled a hole to mount a pressure gauge and very small hole for the exhaust. As expected I had high back-pressure and reduced speed. Drilling out the exhaust hole in small steps caused the back-pressure to drop and speed to increase. (No surprise here) However by the time the exhaust hole was the same diameter as my inlet line I could not detect any measurable back-pressure.

From this I would suggest that the exhaust holes in the disc do not need to have a total area that is more then 2 to maybe 3 times the area of the inlet line. This then would make for a stronger web and disc.

On the edge of my discs I found that if I cut fine sawtooth pattern around the perimeter this gave a substantial increase in speed.

It has been theorized that the air/gas driving the turbine comes in and spins round and round and round until it eventually exits at the center. But what if it doesn’t? What if it takes a more direct path to the center? If that were true then a turbine with multiple nozzles should run faster. To find out built a turbine with 16 nozzles. Each time I opened an additional nozzle I got an increase in speed. However each increase was less then the previous one. Bottom line 3-4 nozzles appears to be the optimum number.

The cross section of the inlet nozzles would appear to want to have a venturi shape. With the proper inlet radius and correct diverging taper on the outlet (3 degree for air) the air/steam should exit at near the speed of sound.

So hopefully this may give you some additional things to think about.

[LeanMixture]

Here are few things I learned and applied to my third prototype:
Tesla turbines are not meant to be used with hot gases it is either air or steam.

Tesla turbine require less mass flow than a conventional turbine but at a higher velocity that is why it could work very well in combination with a vortex tube.
According to the French engineer Sadi Carnot the difference in temperatures of the inlet and outlet results in improvement of efficiency that is why there are researches in precooled air before it enters turbines and that is also why jet engines burn less fuel at a higher altitude because the air is cooler.
So instead of simply allowing the turbine to get air from the atmosphere directly at room temperature it gets it from the cold side of the vortex tube as I explained in my simple diagram and on the other side we use the hot air to heat up the fuel prior to combustion.
Actually my device works without a vortex tube but if I added one I am sure it will work much better but I don’t have it so if anyone has one to spare or donate to this project that would be great.

[MonsieurM]

3D Printed Tesla Valve - YouTube

don't know if you ever saw it at work

and do you think Tesla ever tested with disk magnets instead of simple disks :

Neodymium magnet in copper pipe - YouTube ..... if so what do you think happens the magnets when the RPM is very high ( Magnetic and electric effects on water + Google )...... just wondering

thank you again for sharing your observations of your experiments

[LeanMixture]

3D Printed Tesla Valve - YouTube

don't know if you ever saw it at work

and do you think Tesla ever tested with disk magnets instead of simple disks :

Neodymium magnet in copper pipe - YouTube ..... if so what do you think happens the magnets when the RPM is very high ( Magnetic and electric effects on water + Google )...... just wondering

thank you again for sharing your observations of your experiments

I don’t know what Tesla had in mind but my initial plan before I start my current project was to use magnets on the discs as spacers in a way to repel each other to build a new type of a powerful dc motor and the plan was to have a turbine without a shaft spaced by magnets and submerged in a ferro fluid so when it comes to the space between discs it could be self accommodating depending on the speed and current passed by the fluid. I can post a diagram for it later on I don’t know if it would work or not but I can’t afford to work on two side projects at the same time. Thank you for the videos.