RoadRunnerAerospace

What just happened here

valveless

thats funny, im using epoxy for my pulsejet, which isnt quite as extreme, but its just interesting

I would have never thought that epoxy was exothermic, I'll have to look further into it

Yeah was is looking like the best idea, baking would also harden the epoxy

I think I'm rolling with the epoxy mold idea (I did a couple calculations off paper too if you're wondering where I got those numbers

That is a very good idea, it's sort of like carbon fiber if you really squint

OK so if someone can "sanity" check me that would be great. The thrust caused by a pulse jet is of course, the pressure acting against the walls, etc. So if I were to make it small, and I mean like, 5 inches long, could I possibly reduce the required pressure for combustion/thrust, and therefore heat? I know it works that way with rocket engines (in a perfect world), and pulsejets use a variant of the DeLaval nozzle. As of current i'm looking at a safe run time of 1 minute at 124°c/minute, so at 2 minutes I'll be exceeding maximum operational temperature of the plastic, through the insulating epoxy (Quiksteel), and melt the extrusion material. I'm wondering if during the mixing process I can put some insulator in with the quicksteel to decrease its thermal conductiveness.

if anything it'll be quite fun

nah I've used it on model rocket engines :edit: I've started work on the calculations

I'm not saying its easy, but if I can get the temp within 300 degrees of the melting temp of the extrusion material, I can use gasket sealant used in cars to cover the inside of the pulse jet, maybe more if I can find a better insulator, I'm keeping flight times low for this exact reason, eventually it will melt, I just want to make it usable before it does

Valveless, I think I can tweak the mixture to reduce temp

Hand tools, drill, hammer, and the likes. I can get to a 3d printer at school. The plastic would be easier to manufacture labor-wise, but it would be a little more complex to insulate from the heat

So I was thinking (in the middle of german class), somehow I got from how much I wanted out of there to pulsejets. From there I started to go through ideas of possibly making my own pulsejet, eventually leading me to the question: can I 3d print a functional, and integratable pulsejet for R/C models, etc? The short answer is sort of, yes. The biggest problem with the entire concept is cooling it. I'm saying that a 5 minute run time with throttle to the firewall, preferably 10 at 3/4. SO, after thats out of the way, lets get "technical". PROBLEM 1! Cooling - Pulsejets get hot, like, really hot, so I need to figure out how to insulate the plastic from the extreme temperatures from the combustion PROBLEM 2! Pulsejets are weird, they "pulse" the fuel flow to allow the suction/blow of a normal running pulsejet, I want to keep the jet simple, I.E. no computertrons beep-bopping around with timers, mainly because I cant code. Current progress is stuck at how to insulate the 3d-printed structure from the heat, however I'm formulating an idea, and I'm not great at cad.