applications fuel system for the valveless pulsejet

[Chen]

Why I don't found the use of liquid fuel for the application of the valveless pulsejet?

[Tom]

As far as I am aware Chen, Liquid fuel is alot harder to use in an engine, compared to Gaseous fuel. There has been alot of discussion on this, one of the main stumbling blocks being that to use liquid fuel, you need very good atomization of the liquid. This is not a problem with gas. Still, I am only a beginner here, I moderate and participate in general knowledge/rocketry areas of this forum more then anything.

Tom

[mk]

Hello and welcome Chen.

Nanosoft has gotten a Lockwood type engine to run on gasoline with a relatively simple in-line vaporization setup.

Also Rossco got an engine working on gasoline (if I do remember right) with an internal intake engine by using a vaporization coil.

Actually I don't remember more.
Search a bit and you'll find these two.

Using propane is really much easier/ simpler.

[Mark]

Why I don't found the use of liquid fuel for the application of the valveless pulsejet?

In a sense all our pulsejet fuel is liquid fuel, some just vaporize sooner than others.
Mark

[Chen]

Why I don't found the use of liquid fuel for the application of the valveless pulsejet?

In a sense all our pulsejet fuel is liquid fuel, some just vaporize sooner than others.
Mark

Hi,Mark

atomization or evaporation

The liquid propane or butane is evaporated outside the gas tank(from high pressure to low pressure have different boiling point), so to be accurate it is not liquid fuel .The liquid fuel is atomized and got a small size oil from nozzle.It is more poweful then gas under the circumstances of not any compressor.Because the liquid phase(atomization) is smaller volume than gas phase(evaporation) with the same mass.

your comments and directions are welcome.


I am pool at English grammar .

[Eric]

Was nano using some sort of fuel pump or just a vaporizer coil and a venturi aparatus? I was using a vaporizer coil wrapped around the tailpipe of one of the FWE's I made but I only tried it with propane so It was basically just a propane preheater.

I got a pressure tap system from a RC plane setup and hopefully that will be enough. Between any suction from the fuel nozzle end and any pressure from the tap it should work, hopefully, maybe, if Im lucky.

Eric

[mk]

Was nano using some sort of fuel pump or just a vaporizer coil and a venturi aparatus?

Nanosoft used a pressurized fuel supply, no vaporizer or preheating coil if I do remember right.

Rossco used a vaporization coil around the internal intake at one of his deep throat engines.

[Mark]

Why I don't found the use of liquid fuel for the application of the valveless pulsejet?

In a sense all our pulsejet fuel is liquid fuel, some just vaporize sooner than others.
Mark

Hi,Mark

atomization or evaporation

The liquid propane or butane is evaporated outside the gas tank(from high pressure to low pressure have different boiling point), so to be accurate it is not liquid fuel .The liquid fuel is atomized and got a small size oil from nozzle.It is more poweful then gas under the circumstances of not any compressor.Because the liquid phase(atomization) is smaller volume than gas phase(evaporation) with the same mass.

your comments and directions are welcome.

I am pool at English grammar .

Chen, of course you are right in the strictest sense. But in both cases the fuel is changed into a gas, one just further down the line or in the jet itself. If you wanted, you could have a sealed steel fuel tank with methanol operate in the same fashion as propane. You would have to have a heat source to boil the methanol though and controling the pressure "might" be critical. Methanol boils at 64.96 C or 148.93 F.
To gasify and pressurize a smaller amount of methanol at a time by using a steel fuel line would be safer and heat from the engine will work, you "just" have to work out the logistics. Once someone figures out a good safe way to do this, most valveless pulsejets would benefit enormously from not having to carry the weight of a high pressure propane tank. And high pressure tanks are no fun if your fuel line springs a leak! I use to be a balloonist crewman and heard of some bad accidents, and you would think, what could go wrong in a peaceful hot air balloon.
Chen, you English is fine and I'm glad to see you.
Mark

[marksteamnz]

From DIYGas Turbines re liquid fueled valveless pulse jets.

Quote
Date: Sat, 08 Jan 2005 17:09:18 -0000
From: "thehappypilot2000" <happypilot@aol.com>
Subject: Pulse Jet Kart

Hi all,
Just uploaded a few photos of my Pulse Kart, including a couple
showing the 300lbs thrust Lockwood 'idling' on diesel. As soon as my
new graphics card arrives, I'll be able to upload some video too!
Regards,
Andy

End Quote

Appears to be injecting at 6 points on the combustion chamber Not evident if preheating is being used. The exhaust on this Lockwood (the long tube) is folded with several 180 degrees bends to fit the kart chassis. Pictures are in the photos section in the pulsekart folder
Note to join this yahoo group the moderator, Chris Krug, checks your response when Yahoo asks you why you want to join it's is not some droid that automatically joins you up.

[Mark]

I've heard of several people using a fuel pump on a valveless. The Lockwood literature I bought from Mr. Lockwood Jr. says you can run any fuel in his Lockwood, you needn't use propane. But it would need to use a controlled feedback system using heat to drive the fuel pump instead of a motor or pressurized tank of inert gas or as Bruce Tharpe uses, a stretched inflatable bladder. Bruce uses a Cline regulator though and you have to have a lower than atmospheric for the fuel to flow. And Mr. Tharpe's engine is valved, the regulator/line works off the throat where low pressure resides in the Dynajet or Bailey.
I bled direct pressure off of the combustion chamber in my little Logan and this pressure was enough to drive a 15 second run of fuel over to the side port where it was ingested. It's a little screamer with hardly any thrust, and since everyone is going Chinese, I figure to angle the side port rearward to get some kind of useable thrust. I later tried some ultra tiny check valves but they worked so well that the engine would run for a bit then die and the stored fuel pressure made the fuel squirt like a miniature severed artery even after the engine quit.
The looped Lockwood would be neat to see Andy. I've got some drawings of some in my Lockwood literature but haven't seen a good color picture of one. Imagine all the heat radiating from such a "small" condensed shape.
Mark

[Bruno Ogorelec]

Bill Hinote got his four-intake Kentfield/Lockwood to work fine with an adapted piston-engine fuel injection system. He spent a lot of time and effort to get it to work properly, but in the end it worked fine indeed.

[Bruno Ogorelec]

I hope Mike Everman is still working on his side-draft Reynst.

If I am right, that engine should be able to use an ordinary carburetor, like the ones they use on lawn mower engines and mopeds.

[Xama]

Appears to be injecting at 6 points on the combustion chamber Not evident if preheating is being used. The exhaust on this Lockwood (the long tube) is folded with several 180 degrees bends to fit the kart chassis. Pictures are in the photos section in the pulsekart folder
Note to join this yahoo group the moderator, Chris Krug, checks your response when Yahoo asks you why you want to join it's is not some droid that automatically joins you up.

The pictures are also available on Nick Haddock's site, http://www.nickhaddock.co.uk/jetgallery.htm, down towards the bottom of the page. He's just posted he's achieved 108.4 mph in it too :-).

Although if you're at all interested in turbo based DIY engines, I would recommend joining the list anyway.

[Mark]

I see the Lockwood is not a multi-spiraled motif as I was thinking of, like a snail, but rather a down, over, around, and back plumbing design. Apparently you can twist them in very odd shapes as long as you hold to some needed geometry. Lockwood's literature I bought has several variations on a theme.
Mark

[Chen]

Hi Marten and Eric

Rossco have to use a vaporization coil . Nevertheless ,it's a gas fuel system .
Definitely , the valveless using propane is really much easier and simpler.But the gas phase fuel takes up too much room under the circumstances of not any compressor( the combustion chamber have a finite volume),so that reduce the intake of fresh air.


ps.How to post the pictures or wmv files on the Forum?



your comments and directions are welcome.

chen
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I am pool at English grammar .