Anybody want to build one of these?

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M

Manticore

Just came across this website: Aircraft
Here's an example:
pulsejet.jpg
Valveless Pulsejet Engine

A pulsejet engine is an extremely simple engine but the problem is the stress placed on the valves causes them to wear out very quickly. To solve the problem this Valveless Pulsejet Engine was designed without any valves, in fact it has no moving parts at all. This engine is so simple that almost anyone can build it with a few simple household tools and without welding any parts together. Starts with a push of a button and will easily throttle from idle to maximum power. This design can be made larger or smaller depending on your requirements. Plus, included is a simple modification that is used in our other engines, you can almost double the thrust. Plans Only.
(My emphasis.)

& here's a real one:
jims_valveless_pulsejet_engine.jpg
 

FritzW

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A friend of mine had a propane powered valveless (he must of bought it somewhere, I'm sure he didn't build it). It was tricky to get it started, very loud and got very hot.

We talked about putting it on his Quicksilver UL but never did (probably a good thing) it was pretty small and didn't have enough thrust for take off but it might have kept it in the air if he took off with the 2 stroke.
 

Dana

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The Gluhareff propane jets were all over Popular Mechanics back in the 1970s, with all sorts of fanciful aircraft that could supposedly be built with them. But oh, the noise! And the need for heat shielding... I did meet a guy who built a helicopter with two of the engines, one at each rotor tip. He never got it off the ground and it's probably a very good thing...


Dana
 
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Blue Chips

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"The Gluhareff propane jets were all over Popular Mechanics back in the 1970s, with all sorts of fanciful aircraft that could supposedly be built with them. But oh, the noise!"

HA HA, boy is that the truth, one has no idea the noise until you stand near a pair of those on rotor blades, you just want to run and hide for your life.
I was at a guys place years ago that built a helicopter using these to drive the blades, actually, he did a marvelous job on the build...... except for a few crucial areas.
When he fired it up propane was venting I.E. leaking everywhere it could and he seemed oblivious to it, just sat unstrapped in his seat, wearing no hearing protection and grinning, I had both index fingers stuck in my ears as far as they would go. It never flew, thank goodness.
 
M

Manticore

It was the "no welding" bit that got me. What are you supposed to use: self tapping screws, pop rivets, glue?
 

Victor Bravo

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My friend brought a Gluhareff pressure jet out here once, mounted on the back of a pickup truck. He managed to light the thing off (5 pound propane bottle for fuel) in front of my hangar. He had said to me "once you jhear one of these things run you will never forget the sound".

Understatement of the !)( $*%& decade.
 

Pops

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Back in 1956 a man put on a demonstration inside the high school auditorium with a Dynajet (pulse jet) . He had a small fan several feet behind it turning a set of wheels. Loudest sound that I have ever heard. Don't know how the windows of the building held up.

Dan
 
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bmcj

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I've hear Dynajets, Gluhareff jets (from a distance), and the Bell Jet Pack; Not sure which is the loudest. Another contender would be the B-52... we had to stop our grade school class every time one would fly over on its takeoff run because we couldn't hear anything else.
 

thump

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idaho
Now that you have spent $25.00 to collected all your parts to build your engine, you must purchase a $1000.00 metal lathe in order to thread the parts. ( this is how things go in my life) ;)
It was the "no welding" bit that got me. What are you supposed to use: self tapping screws, pop rivets, glue?
 
Last edited:

Urquiola

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Interesting the Pulse Jet and the blade tip ramjet in helicopters. Any one having a reference to a 300 lb thrust PulseJet plans? Blessings +
 

Urquiola

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Madrid, Spain
Just came across this website: Aircraft
Here's an example:
View attachment 45148
Valveless Pulsejet Engine

A pulsejet engine is an extremely simple engine but the problem is the stress placed on the valves causes them to wear out very quickly. To solve the problem this Valveless Pulsejet Engine was designed without any valves, in fact it has no moving parts at all. This engine is so simple that almost anyone can build it with a few simple household tools and without welding any parts together. Starts with a push of a button and will easily throttle from idle to maximum power. This design can be made larger or smaller depending on your requirements. Plus, included is a simple modification that is used in our other engines, you can almost double the thrust. Plans Only.
(My emphasis.)

& here's a real one:
View attachment 45149
How long will this resist the redglow heat, and how would you cool it for not destroying airplane? Salut +
 

Vigilant1

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It would seem possible to use a small pulsejet like this as the "hot section" of a sligtly more efficient engine. Simplest: put a casing around it to form an ejector (the exhaust gases "pulling" a large volume of entrained ambient air backward to make more thrust). This would also shield other airframe parts from the radiant heat and maybe decrease noise (a little). Or even some sort of turbine/fan on a single disk just to move more air with fuel that has already been burned.
Of course, the pulsing nature of the flow and its extreme heat are an issue. And did we mention the noise?
 

Bill-Higdon

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Feb 6, 2011
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Salem, Oregon, USA
IIRC there was a pulse jet powered homebuilt back in the late 60's or early 70's it made a short blurb in Sport Aviation,. It was a pod fuselage with twin booms for the tail, it's first problem was the horizontal tail surfaces were in line with the exhaust. Crispy
 
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