Brushin off Haters wit 1750°F Bright Yellow Glowing 304 Stainless My Pulsejet n Video

Nick could be in the running for a Darwin Award.

 

Unfortunately, that's what I'm afraid of. No doubt, he's incredibly smart. But overenthusiasm and intelligence can be a dangerous mix. I just hope he's talking all precautions possible.

 

Given the thinness of the material I would think that failure would consist of rupture in the combustion chamber followed by it shutting down, i.e. a rather non-catostrophic event. The fire hazard would appear to be the big concern.

It looks much more benign than rocket motors, but then again, looks can be deceiving.

 

If you decide to build a Mark II version....use 321 stainless, it is MUCH less prone to cracking than 304

 

The V1 "buzz bomb" used by the Germans against the Brits in early WWII was also a pulse jet.

 

Yeah, BUT -- it was a one-shot deal. Those didn't have to endure multiple heat cycles.

 

There are RC scale jets that use pulse jets for propulsion. I bet you could ask on some of their forums about the life of the engines.

AFAIK valveless pulse jets are used mostly as radiant heaters, they aren't as good as valved PJs because so much of their energy gets trapped within the chambers used to maintain the cycle and disipated as heat thru the walls.

Impressive sight though.

 

Let's not go there...

 

Nothing political. Just a note about the buzzing sound a pulse jet makes and commented on by Mr. Thiam.

As long as Britishers could hear the buzz, they knew they were safe. The thing would land and detonate about 10 seconds after the buzzing stopped.

 

heh....


the propane tank is about 5ft away. I probably should move it further away, but what's really going to happen? It isn't so close that it is getting hot. It stays very cool, especially due to the liquid propane vaporizing, there is condensation around it.

i'm not going into the Darwin Awards! I know what I'm doing I've studied this for atleast 2 years and know what I'm doing (again!)! more so than a lot of people responding to this thread

it is making around 20lbs of thrust. There are 4 springs on that rig and they won't even move until you put about 11lbs of force on them, and there is a lot of friction in that stand. I really need to get some drawer slides for a good stand, but was pressed for time due to school deadlines. It basically slides around on the metal, i had some "bearings" (steel tubes) over the "axles" to assist in sliding but they just lock up due to them not being manufactured to have a smooth I.D.

Not much pressure is involved in this motor!!! In an ideal 1ATM fresh (cool) air chamber the most pressure produced is about 50psi. This is a very hot air chamber and the only compression it has is from the momentum of the incoming post-combustion forces (like you combust something it moves outward but has to come back together due to heat expansion and then it cools and comes back) air is elastic and will make a little compression but not much and this chamber is extremely vented. no chance of rupturing!!!!

 

Nick, you never cease to amaze me. People express concern about what you're doing and only offer hopes of safety for you and advice, yet you go out of your way to throw out insults as to how much smarter you are than the others posting in this thread. Do you simply not learn? I have never doubted your intelligence, but for the love of God, would you work on your friggin' common sense and learn to be polite and occasionally, God forbid, humble? No ones going to appreciate a damn thing you do if you keep that crap up.

 

I was saying after studying this subject for years I should know more than some of the people posting! like the ones with the darwin comments and blowing stuff up. It just pisses me off when people think I dont know what I'm doing. Like the bitch who runs the science fair at my school who said this project is too dangerous for me to enter, even though she hasn't even seen it.

in response to JamesG, valveless pulsejets have come a long way in effecieny. furthermore, it is not because they lose heat through the chamber walls. A valved pulsejet and a valveless pulsejet work on the exact same cycle. The only difference is the valved pulsejet has a one-way valve in the intake and is a straight pipe. The valveless pulsejet instead uses a rearward facing intake so that thrust released via the intake becomes usable thrust. The valved PJ will always be more effecient, but the valveless pulsejet has come a long way and is very close to a similar effecieny and makes up for the effecieny loss with a massive advantage in the reliability area and how long they can run. Max run time for a valved PJ is about 30min if you make very good valves, then you need new valves!!! The Valved PJs big advantage is their ability to have more compression since the intake is closed during compression. There is a Chinese or Advanced FWE engine that looks very similar to a valved engine but with a rearward facing intake protruding from the conical chamber to tailpipe adapter. This allows them to have higher compression than the Lockwood-Hiller style pulsejet.
Chinese:

AFWE:

Valved:

Lockwood-Hiller Style:

Thermal Pulse (Chinese and Lockwood blend):

 

Bye bye nick, I let the other posts slide but now you're flaunting it. See you in a few weeks.

 

Can I still PM a banned user?

This is unfortunate because I got about 1/2 the info I needed. FWIW has nothing to do with PJ's

I need to pick his brain !!!!

 

10mm, make it snappy. I ain't got all day. My bannin' finger has got an itch that only a bannin' will scratch.

 

Well, it's not THAT pressing. Just curious.



As you were, sir.

 

how? by making my own post or trying to respond to people thinking I'm going to blow myself up? i get the idea you don't seem to like me much




and about the "runs without failure". stainless should last pretty long. it doesn't oxidize away like mild steel. it will form an oxide layer that kinda acts as a barrier tho. also, I have only mounted it in that one section to try to allow for minimal thermal expansion/warping problems. i don't know about how brittle it becomes and stuff like that tho. don't metals become more flexible from annealing or something?? Britt, what do you think about the metal becoming brittle?

 

Nick, it has nothing to do with if I like you or not. It has to do with Mongo giving you a time out and yet here you are.

I let it slide for a bit but now you're pushing my naturally good nature and my fear of confrontation.

 

but it's a jet engine!!!!

 

and If you'd shut up for a while I might forget you're here.