Valveless pulsejet with afterburning augmentor

This was an experiment I did about four years ago to see if injecting fuel into the augmentor of a pulsejet would increase the thrust. It didn't -- but there were some pretty flames :-)

Category:

Autos & Vehicles

Tags:

• pulsejet
• pulse
• jet
• valveless
• lockwood
• afterburner
• engine

[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.

[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.

[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.

[tokyoscramble]

i bet your neighbors love you...

[blahdob]

that made you jump eh?

who wants me to make a hydrogen pulsejet?

[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.

[GonG108]

@xjet and nuke your damn neighbour , hahahahaaaa

[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..

[MagnesiumAlloy]

so how many pounds of thrust?

[charliepossenriede]

@blahdob haha i do.

[TradeMark2003]

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

[maydayfire]

that thing wants to move forward and your holding it back