TP180-18 starting to take shape!!

[NickC]

Diesel Run 1 didnt get to full throttle (turned it up too quick, rich extinct before max thrust) http://www.youtube.com/watch?v=LZ2sPAwcxDU

[NickC]

Full List of Videos:
First Run (over throttled to rich extinction)
http://www.youtube.com/watch?v=LZ2sPAwcxDU
Second Run
http://www.youtube.com/watch?v=ncUx1k9szfY
Third Run (really hot run!)
http://www.youtube.com/watch?v=lwSpGkHRc84
Fourth Run (another beatifully hot piece of stainless)
http://www.youtube.com/watch?v=FlKDPYYr59E
Fifth Run (business end view)
http://www.youtube.com/watch?v=qJ_l0TyPXJc
Sixth Run (like fifth, but includes a flame out and you can see the thrust measuring springs slack up after the thrust ends and a big diesel flame comes out)
http://www.youtube.com/watch?v=26FymT9dDzM[/QUOTE]


someone get me my frequencies!!!

BTW I tried that damn Visual Analyzer and it crashed the computer!!! It couldn't handle the jet and it crashed!!!

[Eric]

Congratulations, That is an awesome job, very HOT!

Did you manage to convert the spring pull length to thrust yet and get any preliminary figures for the different fuels?

Your teacher should absolutely love it!

The flames the engine shoots out the intake are a really good demonstration of the flow around the engine. Did you notice the fire gets blown out of the intake, and then sucked back and down into the tailpipe with the massive charges of fresh air?

If you can find an emulsifier you can mix things like water and oil to form an emulsion, basically you want to mix gas and alcohol without them separating. I guess it depends on if your using pure 100% dry methanol, or the stuff that they sell as "mineral spirits" which is typically junk since they have all kinds of other crap in it depending on the brand.

If your using mineral spirits from home depot or wall mart that is likely your problem in not getting it to run.

I have found the bit of gasoline gives it a little extra pep and makes starting easier if your having problems with pure methanol.

Eric

[mk]

"NickC",

Very nice going! Congratulations that you got the engine to run! Even nicer it is, that you achieved it with diesel. Cool!

For analysis I found video #4 most representative. However, I have not (had) the time to have a look at all of the videos (yet), but the following can be stated:

OCF: f1 = 132.02 Hz (average of 7 samples) -- open-pipe solution

There is some further harmonic backround in the signal which demands evaluation.

E.g.:

f2 = 193.07 Hz (average of 6 samples) -- open-pipe solution (4th and 7th harmonics are missing probably destructive interference with f1)

Frequencies around 65, 119 and 143 Hz show interesting probability on further harmonic influence, even though being low in amplitude.

Problems were caused by switching between different analysation tools. E.g. Virtual Analyzer seems to put out one or the other frequency larger in magnitude than Audacity does. Quite interesting though.

[NickC]

Maybe the fuel pump? it's fairly quite though.

thanks for the frequencies!!

193hz is pretty good too right?? Eric what is the acoustic length of the TP180-18? with a +2" intake...

[mk]

193hz is pretty good too right?? Eric what is the acoustic length of the TP180-18? with a +2" intake...

That was just one of the "sub-frequencies", which was rather easily oserved, however, OCF (here called f1, of 132.02 Hz) is of your interest, due it characterises operation overally.

[Eric]

I actually dont use "acoustic length" for anything so im going to have to look around and see what you guys are using for end correction factors. Isnt there also another inch in the tailpipe also?

I am wondering if you are getting the actual pump sound, unless you got a hell of a loud pump, I dont think the camera microphone signal to noise ratio would be sufficient to distinguish such a low dB noise with a pulsejet running beside it with any degree of accuracy.

Eric

[NickC]

well, needless to say, it ran and made a great project, but it wasn't allowed in the science fair :roll . too dangerous :roll: . what bullshit!!! the best part is that the teacher who banned it didn't even see it!!! she went on about this thing that since I was pumping gasoline/diesel that I could create static electricity by something as simple as my jeans rubbing together!! (gee willickers!!) and then she proceeded to tell about how gas stations have caught on fire form static electricity!! (unbelievable!!!!). What she didn't realize, and I guess I messed up by assuming she wasn't retarded, is that I am pumping gas OUT of a container, which instead of making vapors come out of a container, actually creates a slight low pressure zone and does not allow vapors to escape. I tried to explain that to her and her response was "do you even know what you are talking about?" stupid bitch. Then everyone who saw the video was like whoa! that propane tank is really close. It looks closer than it is, it's about 6ft away. 6ft is still a little on the close side, but 6ft from a small jet is about the same temperature as where propane tanks are usually RIGHT NEXT TO A GRILL! furthermore, the propane hose (much closer to the jet) would melt before the propane tank was heated to any temperature that would weaken it. AND since my injector flows much less than does the hose there would be an increase in flow which would shut down the tank!! but none of that really matters since it will never happen!

[Irvine.J]

Deleted...lol
check PM

[Eric]

I love those kind of people.

You should have said that a static sparked fire would be impossible because there appears to be an extreme deficiency of oxygen in the area, and that some peoples brain cells were showing acute symptoms of oxygen deprevation.

It would have also been funny to tell her that you could just run it on water, and see how she reacted.

Was she a chemistry teacher? I think I had the same one :P

I wish gasoline was half as flamable as everyone thinks, it would make experimental engines a lot easier to run.

I think everyone here would have given you first place at the fair, you can take comfort in that :)

Eric

[NickC]

ha, she teaches CP physics. (cp at our school isn't even on par with advanced middle school classes, cp classes actually do arts and crafts like coloring pictures.)

yeah, i wish gasoline was that flammable. she showed something online that says gasoline vapors can ignite up to 12ft away. yeah maybe if you are spraying gasoline vapors out of an air compressor at say something like, oh i dunno, a nuclear fusion reaction!!!! i couldn't even get propane to ignite with an almost new magneto setup and a sparkplug!

[thecheat]

that's pretty hilarious LOL. I know gas is flamable... and it can ignite from 12ft away, you know, if you leave it in an enclosed room, one that's nice and warm... with a flame going the whole time. eventually it'll blow.

anyways, good job on the engine! regardless of what the teachers say, it's a good project, you get the A++

PS: I heard of something similar with what's called a "hydrogen bomb" the poor kid was nearly expelled for school just because of the name.

http://sci-toys.com/scitoys/scitoys/ech ... .html#bomb

[NickC]

well I wrote here a letter today in AP biology.

the frist sentences: "Due to your arrogance of my project and knowledge, or lack there of, about fuel systems. I have decided to write you a letter informing that I know what I am doing, even though you previously insulted my intelligence by questioning whethere I did or not."
Then I went on to explain to her about vapor containment and how pumping gas into a container and out of one is very different.

the best part was she showed it to my biology teacher and he was holding back from laughing the whole time lol!! she asked him what she should do and he is like I don't know, I'm not part of it lol.

We also had one of his prior students now studying at Cornell in the classroom today. My biology teacher was telling about my project and how awesome it was and his prior student knew a little about pulsejets so we talked about different fuels and water injection. Overall it was a pretty fun day : )