Valveless pulsejet with afterburning augmentor

[windoes98se]

remindes me of the sound of a two stroke

[004nation]

Certain valveless designs are completely self-starting and with augmentors produce large amounts of thrust for their size. If you could efficiently water cool one it could be even more versitile.

[watballs2020]

shits himself at 12 secs...haha.

[tigerklink]

actually they are very efficient their is no moving parts.

[MagnesiumAlloy]

so how many pounds of thrust?

[TradeMark2003]

yeah imagine having to listen to that while on a plane.

[maydayfire]

that thing wants to move forward and your holding it back

[quaxk]

beside the DIY cruise missile, are there any realistic uses for these engines? they seems to have a lot of shortcomings, they're noisy, inefficient, run at high-temperatures, are unreliable and need a starting flow, what's so great about them?

[xjet]

@quaxk They're cheap, they're fun, they're surprisingly versatile and they are just about the only jet engine the average person could build in their own garage.

[GonG108]

@xjet and nuke your damn neighbour , hahahahaaaa

[Skarae]

pertaining to your afterburner/thrust augmentor. it is possible that if you changed your duct design from convex to concave, you might get better thrust via Bernoulli's principle.

[faffaflunkie]

The problem here is there is so little compression in a pulsejet that all you are doing is throwing away fuel with an afterburner. It's like you have constructed a giant Bic lighter.

[RFTAEC100]

i have a sugestion >.> what if you could make a heat sink around the engine and circulate water trough it, then the hot water circulates around the propane tank helping the gas mantain its preasure... It would be pretty eficient, gas tank cools water and the engine warms it up again

[RogatySTN]

i think that the afterburner may have sens if u make some proper air/gas injector(for example like in jet lighters) but not in valveless cause you would f.up resonance

[heytisazn]

is there only a certain amount of fuel inside?

or is there something that keeps putting more?

[Splooshiba]

there will be something inputting a constant stream of fuel

[superbran2008]

i liked that when he jummes at the beginning hahahahaa boom

[ioan21121221]

are these engines actually very powerfull? i mean for their size...cos i saw on a website of a guy who sells these nad a big one like this was only like 20lb, i didnt know if that was thrust or weight.plz help me out.thanks.

[stupidnamenoonecares]

their power to weight ratio is high. they might look big and heavy but they are hollow and use thin steel. they are quite light but evidently bulky.

[ioan21121221]

thanks. i was aware they were light just not sure about bulk to thrust.

[fassenkugel]

but the effiency is low, because the working pressure near atmosferic.

[schl0tte]

Hahahahaha. Hell yeah, that made him jump xD

[blahdob]

that made you jump eh?

who wants me to make a hydrogen pulsejet?

[iloverush123]

I do!

[charliepossenriede]

@blahdob haha i do.

[tangnatalaga]

If it dont have a valve then it should be called a ram jet aint it? How does it pulse, then if it is a pulse jet? I am just curious.

[xjet]

A ramjet uses continuous combustion and only works at relatively high speeds. The pulsejet uses intermittent combustion and produces thrust even when static. It pulses by harnessing a number of different principles of physics. If you look up kadenacy effect and Helmholtz resonator you'll get the idea.

[WpA09]

@xjet cant you make a vid on how to do these? please it would be a great week project when im at home

[statesmanls1]

Accoustics

[poodlelord]

@tangnatalaga Ram jets rely on air entering the engine at high speeds, and thusly a high pressure, to be mixed with fuel then ignited..

[lejink]

would focusing that rear portion increase the thrust? like a jet fighter has an adjustable portion that opens and restricts at different points in throttle.

or would it just restrict flow

[bonecrime]

It would probably mess up the resonance, is my guess.

[MoPar7055]

How would it create more thrust? Wouldn't it need extra uncombusted air for the fuel to mix with? You only have that in turbojets because so much extra air is taken in to cool the blades

[xjet]

An augmentor works by entraining fresh air in the gap between the engine and the augmentor it self -- this adding to the total massflow of the engine. So, the flow in the augmentor has free-oxygen available to support additional combustion, even though the exhaust of the engine doesn't.

[rpaull3]

it will only create more thrust if its not lowering the pulsejet thrust which could easily happen with the backpressure created from the aug, that and the aug burn should happen inside and out of the exhaust can.

[tokyoscramble]

i bet your neighbors love you...

[frederic470]

LMAO

[Darkfoster22]

lol what neighbors

[scaredofgays]

but theoretically shouldnt it produce more thrust. maybe the diameters of the augmentor are just wrong?

[themaddoghimself]

i think it needs to be a 1/3 inch closer to the pipe

[shermadrenaline]

lol a third of an inch eh