Aerospike valveless?

[Zippiot]

If you kept the volume of area and angles the same, think it would run?
My pic was the best I can draw on my cell, and I have given 0 thought towards intake etc.

[metiz]

That's a cool concept: the inverted pulse-jet!

I think it would work but there's a lot more gas resistance from the walls and the internal structure would get mighty hot. Just try it! Nothing to loose - everything to gain

[Zippiot]

Guess Ill have to roll some cones and hop on the lathe this weekend

[tufty]

Hey Zip,

There's been a few annular designs done over the years, but as far as I know nothing like that. It's certainly worth a try, you might want to consider using the "spike" for fuel preheat (which could stop it melting down, too).

[Zippiot]

I was thinking that, but its a very large area inside there would be hard to control fuel once it heated up.
Gotta work on the intake, maybe Ill make the spike ceramic refractory but I dunno if it will stand up to the pressure flux inside the PJ.
So much to do....

[metiz]

Btw zippiot how did you get that first drawing of the thermojet with the red expanding tail? did you make that yourself or did you find it in a thread somewhere 'cause I can remember drawing that exact picture yonder days ago. Don't get me wrong I don't care - just wondering

[Zippiot]

Yeah sorry about the plagerism, just googled valveless pj plans and it took me to an old forum post. Copy-paste etc