Odds and ends

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Mark
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Re: Odds and ends

Post by Mark » Fri Oct 03, 2008 11:41 pm

A clarification. In this video he shoots off some methane and some acetylene balloons, but he neglects to say he added some oxygen to them.
http://www.youtube.com/watch?v=a5EWVXrW28o
Here is the clarification.
http://www.youtube.com/watch?v=X1LwYJ8pDhc

But you could use pure O2 and butane, or pure O2 and some methanol shaken but not stirred in a balloon, or just about anything and pure O2 will yield similar results. Balloons that size could damage your ears big time, so protect them if you toy with this demonstration. My brother said a shop teacher did a balloon of acetylene and O2 and some people threatened to sue him, their ears were really hurting. It would be helpful to keep that in mind if you are running/entertaining with a pulsejet too, just to be on the safe side. It's only funny until someone loses an ear. "ha"
Last edited by Mark on Fri Oct 03, 2008 11:54 pm, edited 1 time in total.
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Mark
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Re: Odds and ends

Post by Mark » Fri Oct 03, 2008 11:51 pm

I liked these little iodine clocks. When I was in middle and high school I read all the good books on chemical demonstrations and college chemistry demonstration manuals. At the time, chemistry seemed so wondrous to me. I guess that's why I like materials science so much.
Skip to 1:30 or so.
http://www.youtube.com/watch?v=V7hYg-XT5RE
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Mark
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Re: Odds and ends

Post by Mark » Sat Oct 04, 2008 12:13 am

So many posts, I don't know if someone has posted these tidbits before. Anyway, yawn away if they have been.
http://www.ttengines.com/technology.html
http://www.youtube.com/watch?v=F8co9nLAcxs

Scroll to the bottom for the X.PJ-16 pulse-jet.
http://jetex.org/archive/jetxfiles/200405.shtml
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metiz
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Re: Odds and ends - the many-body problem

Post by metiz » Sat Oct 04, 2008 4:46 pm

This is a great, fictional (or is it?) read on the many-body problem. Pure genius

http://www.cosmosmagazine.com/node/41
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Mark
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Re: Odds and ends

Post by Mark » Sun Oct 05, 2008 3:04 am

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Re: Odds and ends

Post by Mark » Sun Oct 05, 2008 4:00 am

I would like to do some vapor deposition experiments on my quartz tubing. (Wishful thinking)
Imagine banging out quartz pulsejets in these various colors. I kind of like the platinum/gold yellow if you scroll down. ha
"There are several varieties of this interesting stone. They are not natural, but man altered. The process used to create the various Aura Quartzes is actually very interesting, it combines the natural quartz with a metal to give the stone a vibrant iridescent quality. The crystal is added to a vacuum chamber, heated to over 1600 degrees F, and then metal vapor is added to the chamber. The metal atoms fuse to the quartz giving it a new finish. This process is called Chemical Vapor Deposition. The stones are mainly used for metaphysical properties, but they make incredibly unique pieces of jewelry as well."
http://gemcompendium.blogspot.com/2008/ ... uartz.html
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Mark
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Re: Odds and ends

Post by Mark » Mon Oct 06, 2008 4:10 am

I was thinking of starting a new thread off-topic entitled "What's Mark smoking today?" ha
I came across a bubbler on eBay in the lab glass category though and started to wonder if it might be possible to run a pulsejet feeding off a fuel/air supply, all the fuel vapor and partially the air supplied by a bubbler. And I was hoping the fuel would act as a one-way valve. If the jet could draw air bubbled through a fuel supply and live on that, then that would be a start to work with. Granted there would have to be a re-route kick in during part of the phase to feed the jet enough air as well.
A "liquid valve" is a lot more dense and would offer a much more sudden resistance than an aerodynamic valve blocking reverse air flow, so the fluid would have a hard time getting out of the way fast enough, (what you would want), kind of like the Lockwood photo which shows that it doesn't like to ingest nuts and bolts and things because by the time the inertia starts in one direction with heavier than air objects, the outflow phase is again coming into play.
If nothing else it's a good thought experiment. Maybe a jam jar would appreciate such a system, and thereby have a remote vaporous fuel feed that would lessen the chance of a high/varied temperature gradient in the glass, a typical fuel as we know blankets the bottom of the jar and cracks often appear at the transition zone of where the fuel level resides.
Anyway, I'm just playing around with ideas. Lot's of bubbler designs out there too. Maybe somebody could come up with a workable model. You could even put valves in the bubbler plumbings as well, or routes that might favor bubble flow in one direction over the other.
http://cgi.ebay.com/Ace-Glass-Collector ... otohosting
http://www.ilpi.com/inorganic/glassware/bubbler.html
Some other designs to ponder/"smoke that in your pipe." Yawn I suppose.
http://images.google.com/images?hl=en&i ... a=N&tab=wi
http://jcschumacher.com/_borders/pinkBubbler.jpg
http://www.labcommerce.com/prod_imagefi ... ubbler.jpg
http://www.gasesmag.com/articles.asp?pid=23
http://www.blastwavejet.com/pulsejet.htm
Attachments
Shunned particulates.jpg
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Mark
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Re: Odds and ends

Post by Mark » Wed Oct 08, 2008 2:19 pm

Now don't quote me, but I was watching the news the other night and there were these windmills in Bowling Green, Ohio that seemed worth mentioning. The newsman was holding a microphone up in the air so that you could hear the sound they make, which was a sound that didn't seem to fit what was going on. Maybe someone can dig up more about this, verify the tip speed.
These blades were just barely turning over to look at them, but if I am not mistaken, I could have sworn he said the tip speed was 175 mph. In that respect, it reminds me of when my brother and I strobed a ceiling fan on high speed and stopped the blades in a fairly lit room, which you might think wouldn't work in a lit room, using a xenon flash, while listening to "gale force" winds, really screws with your mind. That's how it seemed watching these windmills I guess, and the slow spin wasn't a smooth spin, but as if the blades were fighting the magnets. Another thing was the weight of each blade, again don't quote me, but it may have been a ton each.
I don't like writing this up without resources to back me up, but the strange sound and how the visual reality didn't mate with what was going on, was what made them so fun to watch. Perhaps I felt a bit like Don Quixote.
http://www.waymarking.com/waymarks/WM36Y8
Last edited by Mark on Wed Oct 08, 2008 7:44 pm, edited 2 times in total.
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Al Belli
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Re: Odds and ends

Post by Al Belli » Wed Oct 08, 2008 2:53 pm

Hi Mark,

The guy said that the blades weighed 22,000 pounds each !!!!!!

Al Belli

Mark
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Re: Odds and ends

Post by Mark » Wed Oct 08, 2008 3:57 pm

Thanks Al, I do vaguely remember something like 22 thousand, but for some reason, probably my extreme state of tiredness after work, it didn't sink in, and I was thinking 22 hundred. I wonder if they have big permanent magnets in them or if they are using electro-magnets to generate the electricity? Did you notice how the blade spin isn't steady?
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Re: Odds and ends

Post by Mark » Thu Oct 09, 2008 4:10 am

Meager tidbits.

"Making magnetic bearings beefy enough to handle the loads a wind turbine would put on them is hard, and would use prohibitive amounts of power just keeping the electromagnets running strongly enough. However, the Worldwatch article says the new Chinese device (invented by Guangzhou Energy Research Institute and Guangzhou Zhongke Hengyuan Energy Science & Technology Co.) uses "full-permanent" magnets, meaning there are no electromagnets, only cleverly placed permanent ones, so it should use no power. It sounds like they will be used on small turbines (perfect for home use), which would be similar in scale to the pumps and industrial turbines currently using magnetic bearings. But who knows, in a few years it might be possible to scale them up."
http://www.worldchanging.com/archives/004708.html

MHD generator
"A magnetohydrodynamic generator directly extracts electric power from moving hot gases through a magnetic field, without the use of rotating electromagnetic machinery. MHD generators were originally developed because the output of a plasma MHD generator is a flame, well able to heat the boilers of a steam power plant. The first practical design was the AVCO Mk. 25, developed in 1965. The U.S. government funded substantial development, culminating in a 25Mw demonstration plant in 1987. In the Soviet Union from 1972 until the late 1980's, the MHD plant U 25 was in regular commercial operation on the Moscow power system with a rating of 25 MW, the largest MHD plant rating in the world at that time. [1] MHD generators operated as a topping cycle are currently (2007) less efficient than combined-cycle gas turbines."
Main article Excitation (magnetic)
"An electric generator or electric motor that uses field coils rather than permanent magnets will require a current flow to be present in the field coils for the device to be able to work. If the field coils are not powered, the rotor in a generator can spin without producing any usable electrical energy, while the rotor of a motor may not spin at all. Very large power station generators often utilize a separate smaller generator to excite the field coils of the larger.
In the event of a severe widespread power outage where islanding of power stations has occurred, the stations may need to perform a black start to excite the fields of their largest generators, in order to restore customer power service."
http://en.wikipedia.org/wiki/Electrical_generator

What are the primary parts of a generating unit?
The Exciter
The Rotor
The Stator
The Shaft
The Turbine
The exciter is itself a small generator that makes electricity, which is sent to the rotor, charging it with a magnetic field.
The rotor is a series of electromagnets, also called poles. The rotor is connected to the shaft, so that the rotor rotates when the shaft rotates.
The stator is a coil of copper wire. It is stationary.
The shaft connects the exciter and the rotor to the turbine.
Water strikes the turbine causing it to spin. Hoover Dam uses Francis turbines.
http://www.usbr.gov/lc/hooverdam/faqs/powerfaq.html
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Mark
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Re: Odds and ends

Post by Mark » Sun Oct 12, 2008 1:36 pm

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Re: Odds and ends

Post by Mark » Mon Oct 13, 2008 1:24 am

Somewhere My Love
I took apart a little music box yesterday. The tines were kind of a study in design, but I didn't come across any applications to pulsejets although the tines do have some similarity to reed valves being a reed of sorts. Strange to see that as the tines leave the base there is an arch support underneath thinning to a flat tine until you reach the terminal end where there is an ever increasing mass along the row, with yet another complex secondary cut. On mine, two of the heavier tines are also ground down further back, a real art and science in tuning. It's just something to ponder I guess. The base in which the reeds are mounted has a hollowed out cavity/indentation, so that when screwed down to the base the unit sits on a "lip" all the way around. The base of the reed bank is perfectly flat. When I put the thing back together the screws don't help in the least in aligning the tine unit. If it is not perfectly cocked, the tines can barely be heard when played. I never did get it to play as loud as it did, try as I might there is so much play or slide every which way, a delicate little thing. One other part I liked was that spinning fan blade or governor, softly purring, doing it's thing. ha
Might that one pulsejet design with a spinning propellor in the intake/throat function in some similar way I wonder, another feedback mechanism? Or might the spinning blade be more of an atomization of fuel effect or perhaps store energy making the pulsejet less likely to flameout? It would be fun to build one like that maybe.
http://www.flickr.com/photos/eateveryth ... otostream/
http://www.flickr.com/photos/eateveryth ... otostream/
http://www.flickr.com/photos/eateveryth ... otostream/
Number 21
http://www.pulse-jets.com/pulse3.htm

For illustration. ha
http://www.youtube.com/watch?v=oVkjoOzf ... re=related
http://www.youtube.com/watch?v=8yJYqxdW ... re=related
Last edited by Mark on Mon Oct 13, 2008 3:46 am, edited 1 time in total.
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Re: Odds and ends

Post by Mark » Sat Oct 18, 2008 5:33 pm

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