Gluhareff 130R power failure issue still open ... Any Idear?

[Viv]

I may have missed this somewhere in your discussion, but I do not remember any discussion about the metering disk at the fuel inlet to the heat exchanger. From conversations I have had with builders of the engine, this was a very important, but often overlooked part. Fuel inlet pressure to the coil is not as important as the pressure that actually makes it to the nozzle. What is the size of the opening on your metering disk, have you tried changing it and are you measuring fuel pressure at both the fuel inlet to the heat exchanger and at the nozzle?
Dave

Bugger bugger bugger, I forgot about the that restrictor again, I made a mental note of it from the patent information and in my drawings but forgot to ask the question! thanks for that Dave.

Luc can you tell us what ristrictor size is fitted to the inlet of the heat exchanger coil, I meant to ask you before as your nozzle temperature is the same for most settings.

And as Dave asked were are you taking your pressure readings from.

Viv

[luc]

Okey,

As for the question for the meetering orifice ... He he he ... We Also have tried them all. We tried .040", .060", .063", .078" (Gluey Specification), .090", .100" and .125". And it changes nothing. Doing that, you will have a few pounds, more or less, but no big difference.

I told you guys ... We have tried everything. We even designed a way to make those meetering orifice interchangable.

Okey Viv... You said that our evaporator coils have good performance.
Welllll, now is the interesting part ... You guy want to know a secret? ... Sit down tight on your chair ....

The 2 evaporator coils inside our engine... They are of 316L Stainless Steel of .035" thick wall... And Na na na ... Don't go thinking "that it, that the problem", because we tried .020", .028" and .035" and it changes nothing ... We always had between 40 to 62 pnds of thrust.

I beleive that we are starting to lift all the mystery on that engine and I also think that Gluhareff made all the world beleive his engine were so touchy, just to keep the competition away... I am starting to beleive that this engine, is no more then a flaw and 130R is just a model number.

So ... I you guys want to build your self a 40 pounder and cheap... Well do it and you really don't have to use the material specified, because we tried them all, and followed Gluey specification and then followe OUR specification. The results is the same for all 3 engines.

Cya later guys .....

Regards,

Luc

[Viv]

Okey,

As for the question for the meetering orifice ... He he he ... We Also have tried them all. We tried .040", .060", .063", .078" (Gluey Specification), .090", .100" and .125". And it changes nothing. Doing that, you will have a few pounds, more or less, but no big difference.

I told you guys ... We have tried everything. We even designed a way to make those meetering orifice interchangable.

Okey Viv... You said that our evaporator coils have good performance.
Welllll, now is the interesting part ... You guy want to know a secret? ... Sit down tight on your chair ....

The 2 evaporator coils inside our engine... They are of 316L Stainless Steel of .035" thick wall... And Na na na ... Don't go thinking "that it, that the problem", because we tried .020", .028" and .035" and it changes nothing ... We always had between 40 to 62 pnds of thrust.

I beleive that we are starting to lift all the mystery on that engine and I also think that Gluhareff made all the world beleive his engine were so touchy, just to keep the competition away... I am starting to beleive that this engine, is no more then a flaw and 130R is just a model number.

So ... I you guys want to build your self a 40 pounder and cheap... Well do it and you really don't have to use the material specified, because we tried them all, and followed Gluey specification and then followe OUR specification. The results is the same for all 3 engines.

Cya later guys .....

Regards,

Luc

316L is ok if you have made sure that the temperature gradiant across the coil material is not so steep and the fuel flow rate so high that insuficiant heat is applied to the fuel.

The restrictor and coil materiel are only part of the story, the fuel flow rate must be factored in.

If the coil floods with liquid propane the temperature gradiant will be to high hence poor thrust.

The patent also mentions the heat breaking the propane down to propeline.

At this stage I am more concerned with the design of the fuel nozzle, we are happy that the propane is up to a temperature that will stop it going back to a liquid as soon as it leaves the nozzle now we need to know is it fast enough.

Again in the patent it is called a supersonic nozzle and we should take note of that.

Somebody with some rocket nozzle experiance is required for that one though, do I hear any offers! :-)

Next is the cones and its acoustic performance, can you do a sound recording of your engine running?

Viv

[luc]

I hear you,

But sorry for the recording ... We have no such equippment here and the budgets for develloping this engine or bying more equippment is coming close to be empty. If the solution is to be found ... It must not be, it must not be an expessive one.

We are starting to think that we have covered it all ... Unless you guys come with a surprise solution, We are closse to the conclusion that this engine is a flaw ... And this planet has yet to see a 130R Gluhareff engine that deliver 130 pounds of thrust ... Even 100 would be satisfactory ... But the reality is far from that ... This engine real capabilities probably died with Ugene ...

Sometime, if you gard a secret to well ... It dies with you ... Shammeeee.

Regards,

Luc

[Viv]

I hear you,

But sorry for the recording ... We have no such equippment here and the budgets for develloping this engine or bying more equippment is coming close to be empty. If the solution is to be found ... It must not be, it must not be an expessive one.

We are starting to think that we have covered it all ... Unless you guys come with a surprise solution, We are closse to the conclusion that this engine is a flaw ... And this planet has yet to see a 130R Gluhareff engine that deliver 130 pounds of thrust ... Even 100 would be satisfactory ... But the reality is far from that ... This engine real capabilities probably died with Ugene ...

Sometime, if you gard a secret to well ... It dies with you ... Shammeeee.

Regards,

Luc

Well to do the recording you are using the equipment now! a good sound card in a PC will do to digitise the sound and save it to your hard disk but you should try and beg steal or borrow a reasnable microphone and preamp with a line output.

The cheap PC microphones are pretty cruddy.

With that we can do an FFT to see if the main engine dimensions match the cone stack.

The software is shareware, the mac version we use is $30 but you can run it in demo mode if you want, if you want a PC version you can do a google search for a free one.

It also will do it in realtime so you should be able to tune the stacks seperatly to match properly the harmonics of the engine.

What angle have you got on your last cone, the one setup as the quarter wave difuser?

What about answering the question regarding your nozzle?

Viv

[Dave]

Luc
Thank you for providing more information on the sizes of metering disks you tried. Can you do the same for the outlet size and other dimensions of the fuel injection nozzle?
Dave
PS: Clarification on where you measured the fuel pressure would also be greatly appreciated.

[luc]

Goode day guys,

Okey, for the recording, I will see what I can do for that. The problem is not the recording and the PC it self. It is to bring the equippment outside or to the engine and we have no laptop, but I will see what we can do.

As for were the pressure reading is taken, well the meter is aprx. 20 feet from the coil inlet. I have 1 meter before the control valve and 1 after. The controls are 20 to 30 away from the engine for safety reason. I guess I could make arrangment to have a gauge at the nozzle. But we did that months ago and our findings were that we had the same pressure at the nozzle, compared the control meter.

As for the nozzle dimenssions, it is as per Gluhareff drawings. A perfect stainless steel copy. The hole is .250" +/- .005" and the shape is perfect. I beleive that nozzle was machined using a CNC late.

So .. here is the answer I beleive you wanted ... Let me see for the recording.

Cya later and good day.

Luc

For

[Viv]

Ok that clears up a few more questions.

I notice that he quotes up to 700psi in the supply line caused by cetnrifugal force when the engine is mounted on a helicopter rotor (original patant doc).

48lb of thurst at 225psi is what at 700psi? your thrust performance against fuel pressure is pretty much a straight line, I make the result remarkably close to 130Lb.

Do you think the quoted figure of 130Lb is only attained on a rotor? I would not be at all surprised as he does point out that these engines are designed for that job so they are probably marketed that way anyway.

If thats true then all we need to do to sort out your problem is work out how to get round the supply pressure problem economically, the rest of your engine is ok.

The heat exchanger circuit can handle it ok so maybe all it needs is a small bore piston pump to get the fuel into the circuit the same way return water is pumped back into steam boilers.

Viv
PS can you fix your web site address in your profile, ta

[luc]

Okey Viv,

I follow you on that theory, wich I think is not crasy at all ... Only one question ... Why is the manual I got when I purchased my first engine, there is a graphic clearly showing "Nozzle Pressure at 165 psi vs Thrust at 130" for the "R" version (Rond intake).

Are you suggesting these graphics are not true and that in fact, they are there for marketing purposes. Personnaly, I think you are getting closer and closer to what might be the real truth.

I will try a graphic of my own to validate what your are saying and I have attached to this message, the graphic we find in the manual.

And sorry for our Web site address ... It is fixed now ... He he he.... Oooops.

Regards,

Luc

[luc]

Okey,

This is what a projection graphic gave me as for the thrust vs nozzle pressure, using what we already know. The results are interesting ... Hummmmm.... Viv ... Not crazy for deduction ... Hummmmm.

[Viv]

Okey,

This is what a projection graphic gave me as for the thrust vs nozzle pressure, using what we already know. The results are interesting ... Hummmmm.... Viv ... Not crazy for deduction ... Hummmmm.

Well looking at that graph i can only agree, it just fits the figures you have got far to well to be able draw any other conclusion at the moment.

Ok if we accept it as what is going on lets see if there is a way to prove it, the simplest way would be to raise the pressure? but I do understand from your previous comments regarding the pumps that may not be easy or cheap.

But is there a simple way? personally I hate the idea of pressurizing a fuel tank too the kind of figures we need so I would like to avoid that if possible.

I still like the idea of a small displacement piston type pump forcing liquid propane in to the heat exchanger coil at a high enough rate to generate the 700psi from the engine heat.

It would probably want a longer coil to get a bit more volume to act as a plenum chamber and even out the pump pulses and also pick up some more heat.

I cant remember from your first posts if you had any power available to run a pump in the final application so I may be whistling up the wind with this idea.

Viv

[Viv]

Ha! I am being dumb! (more than useal:-) I asked the question then forgot to think about the reply I would get.

The nozzle is another key to this problem, altering the pressure to the nozzle will affect the flow and hence the speed of the mass flow only untill a shock wave forms in it, once that happens it will choke and the flow will not increase as the pressure is increased.

Thrust is dependant on the combustion pressure and that is dependant on mass flow rate and speed of the propane.

We only considered pressure in the graph but the nozzle desigh you have cant be good at the low pressures as well as these high pressures, its basically the same as a rocket nozzle, have a look at this link.

http://www.grc.nasa.gov/WWW/K-12/airplane/ienzl.html

Have you tried differant nozzle designs?

Viv

[Dave]

Luc and Viv
Before moving to a new nozzle design, or a piston pump, how about enlarging the exit for the existing nozzle? With the temperature figures quoted, the fact that changing the metering disk did not change the thrust output and the belief that pressure at the nozzle is roughly equal to that at the coil inlet, could the existing nozzle exit size be the restricting factor? After all if you are about to cut it off to try another design, there is not much to loose.
Dave

[Viv]

Luc and Viv
Before moving to a new nozzle design, or a piston pump, how about enlarging the exit for the existing nozzle? With the temperature figures quoted, the fact that changing the metering disk did not change the thrust output and the belief that pressure at the nozzle is roughly equal to that at the coil inlet, could the existing nozzle exit size be the restricting factor? After all if you are about to cut it off to try another design, there is not much to loose.
Dave

Not that easy I am afraid, its not the size of the hole that decides the flow rate in this type of application it is a combination of the orifice size and the profile of the hole.

The pressure is so high that the stream of gas is accelerated to mach speed in the nozzle, when that happens a shock wave forms, once that has happened you can keep on increasing the pressure but the gas will not go any faster.

We have 225psi in the supply pipe at 1200f (648.9c) so the local speed of sound is 2381 feet per second (726ms) now that 225psi has to be expanded down to what ever the pressure is in the first inlet stack, that pressure will be lower than ambient due to gas stream entraining air with it as it goes through, lets guess and say 10psi.

Expanding the gas from 225psi down to 10psi will also lower its temperature, thats why it needs to be heated so much to start with, if it was not so hot it would just turn back to a liquid as it left the nozzle.

Have a look at DeLavel nozzles on a google search or at the rocket nozzle simulator link below and try those figures, its quite interesting to play with the different nozzles and see what happens to the mass flow rate, you can get it to choke up and then the mass flow stays the same as you increase the pressure.

http://www.grc.nasa.gov/WWW/K-12/airplane/ienzl.html

The speed of the gas leaving the nozzle directly affects the amount of air entrainment (hence mixture) and the final combustion pressure (hence thrust), this will also be boosted by the engine acoustic system (a lot) but that is also influenced by the gas speed and flame front position.

What we cant calculate is the amount of marketing or the truth of any claims regarding what thrust these engines will produce? this is the first time we have got some figures for one of these engines.

Unlike a pulse-jet it should be possible to model one of these motors in a CFD program fairly easily (I think:-) to optimize the design.

Viv

[luc]

Okey guys,

You know ... It is a shame that we are not living in the same city or working together ... I would have LOVE to work with you Viv and Dave.

As for the nozzle size, Viv is correct Dave. Nozzle flow is limited to orifice size and liquid propane suply pressure. If you have 32 liter/minute going trough these orifice at a certain pressure, you will always get that figure unless you change one of those 2 fugure. BUT... I know that the .250" Dia. of the nozzle, probably become .280" or .300" at 1200°F. So, my next move will be to machine a nozzle for it to be .250" at 1200°F (Maybe a .200" nozzle.

As for the pump and high pressure issue. Let me give you a small figure here. A positive displacement pump of 250 psi delta is $12,000.00. Or 2 pumps of 100 psi delta mouted back to back (one feed the other) plus the safety feature required, is aprx. $8,000.00. So ... You can imagine the price of a piston pump working for a propane application (No lubricant in the liquid to be pumped). Piston pump requires a minimum of librication OR they get very very expensive.

Also, I have found a laptop and a micro phone to do an engine max power recording. But I am telling you guys, I am no accoustic specialist and I would know what to do with the sound track. So, If one of you still want it ... just tell me and I will do it.

And Last ... Viv ..... I have a CFD program here ... he he he. Tell me what you want. And this, I am good with it.

Have a good day guys,

Regards,

Luc