Valveless Pulsejet, 100% Effective?

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dadruid
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Valveless Pulsejet, 100% Effective?

Post by dadruid » Wed Jan 28, 2004 3:02 am

I was browsing patents this afternoon and came across this one, in which the author claims to have working models of a valveless pulsejet with ZERO backflow?!? Interesting read, and I think enough dimensions are given to build one. Not to mention the construction isn't that complicated. Too good to be true? Interesting read if nothing else.
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Mark
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Post by Mark » Wed Jan 28, 2004 3:32 am

Interesting patent, fairly recent and seemingly some strong points. I remember long ago on this forum someone mentioned they knew/heard tell of someone working on a Gluhareff of sorts that was of a linear design.
I wonder if this is him.
Mark

Dave
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Valveless Pulsejet, 100% Effective?

Post by Dave » Wed Jan 28, 2004 4:57 am

What you are looking at is definately a reconfigured pressure jet. For comparison I suggest you go to the Pressure Jet forum and check out the recent postings. Just as with pulse jets, these engines are not without their challenges.
Dave

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Post by Dave » Wed Jan 28, 2004 5:00 am

Dadruid
Any additional information you can find / provide on this design would be greatly appreciated, especially if someone has one running.
Dave

hinote
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Post by hinote » Wed Jan 28, 2004 5:19 am

Mark wrote:Interesting patent, fairly recent and seemingly some strong points. I remember long ago on this forum someone mentioned they knew/heard tell of someone working on a Gluhareff of sorts that was of a linear design.
I wonder if this is him.
Mark
It's continuing to be apparent that there's nothing new happening in this field.

Look at US patent #3,035,413 for a similar concept. It's dated January, 1950.

Bill H.
Acoustic Propulsion Concepts, Inc.

Viv
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Post by Viv » Wed Jan 28, 2004 11:12 am

I think I have posted this and the other patent number in other threads before, It is a pressure jet type engine but interestingly he calls it a valveless.

One thing to note, he states that it will not run with out the coiled wire flame holder! now he calls it a flame holder but it does not provide a region of recirculating gasses so it is not a flame holder, what it is though is a hot wire ignition device.

we have used the same thing to make a stropy engine behave in the past, basically the wire gets so hot it acts as the igniter even if the rest of the engine is cold.

His engine needs this as it does not have the Glueys sonic lock trick to anchor the flame front to one location.

Viv
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Graham C. Williams
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Post by Graham C. Williams » Wed Jan 28, 2004 1:45 pm

we have used the same thing to make a stropy engine behave in the past
Not stropy. It was just misunderstood.

Graham.

Viv
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Post by Viv » Wed Jan 28, 2004 2:48 pm

Graham C. Williams wrote:
we have used the same thing to make a stropy engine behave in the past
Not stropy. It was just misunderstood.

Graham.
It had a high octane temper

Viv
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Mark
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Post by Mark » Wed Jan 28, 2004 6:08 pm

Viv wrote:I think I have posted this and the other patent number in other threads before, It is a pressure jet type engine but interestingly he calls it a valveless.

One thing to note, he states that it will not run with out the coiled wire flame holder! now he calls it a flame holder but it does not provide a region of recirculating gasses so it is not a flame holder, what it is though is a hot wire ignition device.

Viv
The old Dynajet Co. Dynafog fogger I bought on eBay had what looked like a Z zigzag piece of wire in the body/throat . It was all welded together so when I decided to saw the head off, it turned out it was a chubby coiled spring positioned sideways, probably the same effect as a glow plug to prime/preheat or ignite the incoming gases. The pulsejet design was kind of a Schubert- Dynajet blend, (flat front with a tube attached), yet further upstream beyond the intake tube, was a 90 degree port where a little 6 or 8 petal valve was housed.
It was just interesting to see a chimera, a typical valveless Schubert with a petal valve elbowed onto the intake tube. For when I sawed off the tip of the intake tube, a complete Schubert was left. I sent the old petal and valve plate and interesting cone retainer to Larry to tinker with. The cone retainer at the base where it held the petal down, had a rounded bottom to allow the reeds to curve against it, the tip of the cone fit into an ant lion hole if you will, the air/fuel mix was funneled/elbowed into the Schubert intake.
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dadruid
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How does it work?

Post by dadruid » Wed Jan 28, 2004 8:21 pm

Anybody have a three sentence explanation of how this works handy? A google search didn't help me out much. Also, couldn't the "flame holder" be just that? Can't you use a screen to stop a flame from propogating through a flamable mixture? Maybe understanding how this works will explain why the flame doesn't travel up the valve. Also, does this thing pulse or does it just burn fuel continously? And on another topic, I just picked the original of Lockwood's thesis, "Pulsejet Ejectors," submitted in June of 1953. Apparently he attended OSU. (Oregon State University) This thing belongs in a museum! It has the original approval signatures on it, kinda cool.

Drew

Viv
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Re: How does it work?

Post by Viv » Wed Jan 28, 2004 9:42 pm

dadruid wrote:Anybody have a three sentence explanation of how this works handy? A google search didn't help me out much. Also, couldn't the "flame holder" be just that? Can't you use a screen to stop a flame from propogating through a flamable mixture? Maybe understanding how this works will explain why the flame doesn't travel up the valve. Also, does this thing pulse or does it just burn fuel continously? And on another topic, I just picked the original of Lockwood's thesis, "Pulsejet Ejectors," submitted in June of 1953. Apparently he attended OSU. (Oregon State University) This thing belongs in a museum! It has the original approval signatures on it, kinda cool.

Drew
Three sentances! are you kidding?:-) ok

The fuel comes out of the nozzle at sonic speed and entrains "some" air in the first stack element and starts to slow down and gain pressure, it does the same in the next stack element and gains more pressure but now it is getting "near" the stoitimetric mixture ratio for propane 14/1, it won't burn yet as the mixture ratio is to low.

As it enters the chamber from the last stack element the mixture is now ready to burn and the speed has fallen to a value that about matches the flame speed of the mixture and the pressure has risen as fare as it can (trading speed for pressure)

The pressure in the chamber is the same as the mixture pressure at the chamber entrance so no blow back but it is unstable, the flame holder is just a red hot glowing wire that reignites the mixture if the flame is blown out becouse the mixture is going to fast, it does not "hold" the flame.

well I could have done with another sentance to cover the heat exchanger but I will leave it for now.

One last observation is that this motor will run in an intermitant manner not becouse it is a pulse jet but becouse of its unstable dynamics, it is an intermitant pressure jet, trying to get the ballance between the speed of the mixture and the flame speed is going to be like ballancing on a knife.

Take away the hot wire igniter and it will just blow itself out all the time.

Maybe a good name would be dynamic pressure jet were the Gluehareff is an acoustic pressure jet.

Viv
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dadruid
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Post by dadruid » Thu Jan 29, 2004 7:27 am

Okay, maybe four sentences next time, but any more than that and I think it would start making less sense. :-) Anyway, thanks for the info. I did come across the Gluhareff pressure jets while googling, the G8-2-130 doesn't look very big for the claimed 130lbs of thrust, what kind of fuel consumption do these guys have? (Compared to valved or valveless pulsejets of similiar output) If I ever get a working valveless pulsejet built, it might be interesting to compare the two.

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Post by Viv » Thu Jan 29, 2004 9:39 am

dadruid wrote:Okay, maybe four sentences next time, but any more than that and I think it would start making less sense. :-) Anyway, thanks for the info. I did come across the Gluhareff pressure jets while googling, the G8-2-130 doesn't look very big for the claimed 130lbs of thrust, what kind of fuel consumption do these guys have? (Compared to valved or valveless pulsejets of similiar output) If I ever get a working valveless pulsejet built, it might be interesting to compare the two.
What kind of fuel consumption? the kind that makes an Arab prince smile:-)

As to the gluey engines have a look at the 9 page thread on the g8-2-130R thats in the pressure jet forum.

Viv
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