Slightly OT - pulsejet static vid.
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Slightly OT - pulsejet static vid.
Just for some giggles here's a link to a static test of the bigger of two pulsejets I have. 18lb thrust at full bore, which is a flow rate of 340cc/minute on gas/kerosene blend. Video does not even come close to reproducing the mayhem and racket these things make, you just have to be there.
The sudden "BRA-A-A-A-A-A-A-A-A-A-A-A-A-A-P...................silence......................" when they shut off is well represented here though, if you crank the sound a bit.
[link=http://www.truerc.net/jetengine.avi]Maxjet-15 static test[/link]
MJD
The sudden "BRA-A-A-A-A-A-A-A-A-A-A-A-A-A-P...................silence......................" when they shut off is well represented here though, if you crank the sound a bit.
[link=http://www.truerc.net/jetengine.avi]Maxjet-15 static test[/link]
MJD
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RE: Slightly OT - pulsejet static vid.
ORIGINAL: combatpigg
Is there much vibration compared to a piston engine?
Is there much vibration compared to a piston engine?
But to answer your question honestly - having never flown a jet c/l model, I have not had the opportunity to hold a model with one running, so have not directly felt it. The thrust cycles from peak to zero or a bit negative every cycle, it can't be all that buttery smooth.
MJD
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RE: Slightly OT - pulsejet static vid.
ORIGINAL: vicman
Way cool!
Way cool!
MJD
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RE: Slightly OT - pulsejet static vid.
ORIGINAL: airbusdrvr
I could not get the sound from the link/video. What am I doing wrong?
I could not get the sound from the link/video. What am I doing wrong?
The problem is definitely not due to a lack of sound..
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RE: Slightly OT - pulsejet static vid.
ORIGINAL: combatpigg
That was just a bird that the engine was digesting.
That was just a bird that the engine was digesting.
You know, I should try firing a bug down the intake next time I fire one up.
Actually yes, he is throttling it in this video. You can probably throttle it down about 40% in the air, but since it is strictly fuel flow the mixture goes haywire. Here, the video is supposed to demonstrate that you can throttle it down to something like 2 pounds thrust. That's fine running static, but try that with 150mph air howling through the intake and I bet it flames out instantly. I don't think they've flown their prototype yet. I spoke with someone with much pulsejet RC air time, and he said he uses the fuel flow more to adjust the mixture to his liking in the air, adding that on down lines he gives it full fuel flow, and as it slows down in climbouts or high-g maneuvers he would pull the stick back to keep the mixture from going too rich.
Speaking of throttling, I got a toy in the mail today. Gonna need a bit bigger delta than the Demon for this. Not much tho'..
p.s. PSP ought to take note here - not only will their test stand easily hold a pulsejet as seen here, but with two plywood tabs the turbine will bolt right in. Cool. Fire and noise party tomorrow.
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RE: Slightly OT - pulsejet static vid.
.......that dynajet could be strapped to a plane with twin fins rigged up and flyable by lunch time tomorrow. I would run it mounted on an aluminum strap and get a feel for pitch control / thrust angle with a helper or two, make adjustments to get an equal amount [feel] of pitch control from neutral, then head out to the field.
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RE: Slightly OT - pulsejet static vid.
ORIGINAL: combatpigg
.......that dynajet could be strapped to a plane with twin fins rigged up and flyable by lunch time tomorrow. I would run it mounted on an aluminum strap and get a feel for pitch control / thrust angle with a helper or two, make adjustments to get an equal amount [feel] of pitch control from neutral, then head out to the field.
.......that dynajet could be strapped to a plane with twin fins rigged up and flyable by lunch time tomorrow. I would run it mounted on an aluminum strap and get a feel for pitch control / thrust angle with a helper or two, make adjustments to get an equal amount [feel] of pitch control from neutral, then head out to the field.
If I find some really tall grass, maybe I'll do light bungee "tosses" power off first. I am not entirely convinced at that point it makes any difference if the engine is on or not with regards to the outcome though.
MJD
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RE: Slightly OT - pulsejet static vid.
ORIGINAL: airbusdrvr
I could not get the sound from the link/video. What am I doing wrong?
I could not get the sound from the link/video. What am I doing wrong?
MJD