Bruno's swirl can concept

[resosys]

I'd say we need a piece of pyrex on one or both ends of the combustion can and access to a super high speed camera. It would be really neat to see the entire engine cycle in super slow motion. We'd learn a ton, maybe.

Anyone that's coming to the meet have time to whip one up? Ha.

Time, we need more of that, too.

Nice work Bruno and Al.


Chris

[Mike Everman]

Bruno,
The back of my envelope says the intake gas entering your chamber is far from making a circuit around the wall.

From the dimensions, I'd throw an estimate of about 250 Hz, giving you a 4msec cycle.
One quarter of that is 1 ms, give or take, the time to be breathing in.

Another estimate would be how fast the gas is coming in, and a reasonable peak would be about 120m/sec, for an average of about 60m/sec or .017 sec/meter.

In one msec the gas travels, give or take a lot, 1/17 of a meter or 59mm (2.3"). A circuit around the CC tangentially would be 9".

Any of the above assumptions can be off by a factor of four and it still won't make it around before the pop destroys all that neat flow.

It still is cool, though, and I will drink a beer with you to the possibility that something different is going on!

[Lawrence]

I just saw the swirl can pulsejet, and got this idea. Unfortunatly I don't have a good drawing program, so it's made in Paint

Maybe this might work. If the exhaust is placed in the middle, just like most normal valveless pulsejets, the mixture igniting exhaust backflow shoots through all the mixture inside the combustion chamber, so more fuel/air mixture is ignited faster.


The intake should enter the combustion chamber tangential, as on the swirlcan.

This pulsejet will generate thrust from the exhaust, for linear motion, but the intake gives its thrust tangential, creating rotation

If the pulsejet was put in bearings, it will start turning, creating torque.
Fuel can by injected in the combustion chamber trough the axle connected to the CC


This could be used in aplications using both. This way you can for example build a pulsejet powered kart using thrust AND wheel drive.



The exhaust could also be wrapped around the combustion chamber, also creating tangential thrust, so most of the engine's thrust is used to power an axle.

[hagent]

I can't belive it....

I just finnished my drawing and was going to post it and Lawrence beat me to it!

Oh well.

The small tube is a fuel line. The inner cone has some perfs so that the fuel can enter the CC.

Any thoughts?

Not to scale.

[Mark]

Just some related topics.
Mark
http://www.afrlhorizons.com/Briefs/Jun02/PR0111.html
http://www.lanl.gov/source/orgs/tt/lice ... ogy&id=190
http://www.pr.afrl.af.mil/00/tvc.pdf
Keeping the walls cool.
http://www.nasatech.com/Briefs/Sept00/MFS31477.html
Solid fuel vortex idea.
http://www.nasatech.com/Briefs/Aug99/NPO20594.html

[Mark]

Might be fun to try for ball lightning too, via a vortex generated by a pulsating combustion device.
The closest I got was my green fire ring thrower. ha
Still, it might be something tangible to think about.
Mark
http://www.virtuallystrange.net/ufo/upd ... -002.shtml

[Mike Everman]

Lawrence and Hagen,
the only problem I see is that the spinning will make a partial vacuum at the intake, and the engine will not be able to draw air in.

[Mike Everman]

this is a turbo pj I was trying to get together for the meet, but I've run out of time!
I was puttijng it on bearings like you both suggest, hopefully to drive a propeller. What fun!

I think this is a perfect application of the high velocity gas you'd get from the straight pipe exhaust.

[hagent]

Thanks Mark for all the great links. How do you remember where all the good info is?

Mike I'm a little confused... Wouldn't you want to have a partial vacuum near the intake (inside the engine) so that fresh air would be drawn in?

I've been thinking about what I drew. It may not work so well. If you think about a tornado the large part of the cone is the direction of the flow of air. In my drawing I was trying to force it the other way around. I wonder if something like this would work better? It looks familar.. maybe it's been done before? The fuel line goes to the pointy end.

I hope to see everyone on Saturday. I may just come for the day.

[hagent]

Mike I think I understand where you got the low pressure near the intake from.
In my drawing the PJ would not be spinning. I guess I should have pointed the intake towards the back (got lazy). I was trying to maintain Bruno's fire vortex idea.
I suppose if you did build it with bearings it would spin though (if it ran at all).

[Graham C. Williams]

Dear Mark.

http://www.seas.ucla.edu/combustion/ima ... es_inc.gif

http://www.seas.ucla.edu/~ark/

Graham.

[Lawrence]

Lawrence and Hagen,
the only problem I see is that the spinning will make a partial vacuum at the intake, and the engine will not be able to draw air in.

that possible problem could be solved by builing an air scoop on the intake. It will deliver air in front of the intake, and doesn't effect the exhaust charge too much



It might be even possible to build a ramjet this way, facing the intake to the direction of rotation, as an airscoop, and the exhaust the other way. Spinning it up to a certain rpm would be needed for starting.

[Mark]

For some reason the swirl can topic remined me of this 90 degree angled exhaust.
Mark

[Mike Everman]

Lawrence,
whatever you do, whatever scoops or tricks, the centrifuge is king. If you spin that intake, it will fling gas out, no matter what.

[larry cottrill]

Lawrence,
whatever you do, whatever scoops or tricks, the centrifuge is king. If you spin that intake, it will fling gas out, no matter what.

Mike -

That's right on the money as a description. I think that means, among other things, that the densest [presumably meaning, coolest] part of the gas will run on the outside, up against the cylinder wall, with the lightest gas displaced toward the center. IF the swirl is really enough to achieve that kind of separation, you might be able to use that somehow.

L Cottrill