T shaped Pulse jet?

Bob · Post by **Bob** » Sat Jan 26, 2008 12:42 pm

After studying Bruno's artical on improveing the Pulse jet
I got to wondering about 2 combustion chambers
and one tail pipe....
He mentioned that they made a "T" shaped Gas generator for turbines a long time ago that were of this configuration but they had valves in them ...
So I am wondering .... has anyone ever made a 2 combustion chamber Pulsejet yet ?
the idea Bruno had was to alternate the fireing of the Cumbustion chambers from one side to the other and use the explosion from one side to compress the fuel/air mix in the other side before it was ignited... seamed like a perfect way to up the compression on a Valveless Pulse jet
... though Bruno mentioned that the one that was built and ran, it didn't run as planned. sorta like a moped that backfired everyonce in a while HEHEHEH
....
but the idea is so sound I can't get it out of my mind.
its a perfect way to compress the fuel air and increase the thrust output of a valveless PJ... there has got to be a way to get one of these things to run!
...
So I am thinking just a simple "T" shaped PJ....
nothing fancy the top horizonal section would be the cumbustion chambers with their exhost faceing each other
and the lower extension of the "T" would be the exhost
if a simple "Ugly stick" approach was used and just get the thing to fire up perhaps cramming in enough fuel /air would get both sides to fire automatically... but I'm just guessing
...
it seams a waste to me to have the Answer to the ailing low thrust valveless Pulsejet right in our hands and not be able to get it to run ! or ...run correctly.
... anyone have any ideas on how to do this "T" shaped PJ
before I start welding again?
I figure I'll just weld up something and see if it runs if not then I will know what doesn't work and go from there
hehehehhe
...thats obviously not the most efficient way to go about it
but as far as I know the idea hasn't worked yet anyway.
so anything goes !
your comments appreaciated
thanks !
Bob.......

Bob · Post by **Bob** » Sun Jan 27, 2008 1:48 pm

So No body has made one of those "T" shaped Pulse jets UH ?
wow with all the PJ's out there being home brewed I figured someone would have tried to make one or two at least!
...
I guess I am in virgin teortory then and will have to wing it
hehehehehe
I figure a few basic ideas of CC /2 for the exhost size, intake a hair bigger than 1/2 the exhost... and the lengths will have to be experimented on I'll start real long for the exhost and try to get something to pop and bang and go from there !
...
Bob.......

though I have no idea on how to alternate the spark from one end to the other... but then again that may not be nessarry
if it starts working on compression mode !

Viv · Post by **Viv** » Sun Jan 27, 2008 2:31 pm

Hi Guys

Yes this was tried by Troy Legner with two of his rather beautifully made valved engines and a T peace he manufactured.

the details of his test are in earlier forum posts.

Viv

Bob · Post by **Bob** » Sun Jan 27, 2008 3:38 pm

Ahhh ! Thank you
I've got a bunch of reading to do I see
the 2 PJ's side by side and useing the intake pulse is close
to what I had in mind so I've got some studying to do !
thank you for the help!

Bob....

Mark · Post by **Mark** » Sun Jan 27, 2008 4:14 pm

There was a U-shaped pulsejet which is really kind of a T-shape if you fold the sides down. ha
It had valves at the top of both arms and the combustion met face to face at the bottom of the U where a common exhaust jacketed the two ends and redirected the flow straight "down," the thing looking like a very short handled tuning fork. It alternated firings and was said to have a constant/absolute positive pressure flow out the exhaust, unlike typical pulsejets. Perhaps it was a bit quieter but with the introduction of more complexity.
I was thinking a V-shaped pulsejet would be something to try too. But what to call the first prototype? ha
http://www.pulse-jets.com/phpbb2/download.php?id=4343
http://www.pulse-jets.com/phpbb2/download.php?id=4342

Viv · Post by **Viv** » Sun Jan 27, 2008 4:17 pm

Hi Bob

Sounds interesting to use intake pulses, remember that on a valved engine when the valve is open the engine resonates as an open tube and when closed as a closed end tube.

That has an interesting effect on the fundamental frequency of the engine for valved engines, see hyperphysics for more info on acoustic modes of tubes.

Think about the 180 degre phase shift the Esnault-Peltier engine needs with the above in mind.

Navigate to acoustics/ air columns/ resonance/ Air Column Resonance
http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html

Viv

leo · Post by **leo** » Sun Jan 27, 2008 4:49 pm

Bob, maybe this post is of use to you.
http://www.pulse-jets.com/phpbb2/viewto ... light=bcvp

PyroJoe · Post by **PyroJoe** » Mon Jan 28, 2008 2:08 pm

This isn't a pulse jet, but I stumbled across it on one of my ventures.

PyroJoe · Post by **PyroJoe** » Mon Jan 28, 2008 9:31 pm

This may be useful.

http://www.pulse-jets.com/phpbb2/viewto ... c&start=30

Vermin · Post by **Vermin** » Tue Jan 29, 2008 6:47 pm

So I am wondering .... has anyone ever made a 2 combustion chamber Pulsejet yet ?

You may want to review the SWEFT under conceptual design..it was a fun unit but requires some tweeking that I just havent had time for YET.... have fun.
V

www.pulse-jets.com

T shaped Pulse jet?

T shaped Pulse jet?

Troy Legner

Open and closed

BCVP