shinobi909

Thanks liquid, for the explanation. Just explain 2 things for me what are 2LoT and dS>=0 abreviations for?

Max Bane

I guess I'll jump in while I'm here.
2LoT = 2nd Law of Thermodynamics
dS>=0 = change in S (Entropy) is greater than or equal to zero. This is a result of, and sometimes definition of, the 2LoT.

echidna

Just very very quickly, can even the author explain this formula ?

“frequency of the kinetic energy” ???
“p represents a photon” ??? It's units are 1/Ns if that helps at all.

The article has a phenomenal lack of supporting mathematics & just the first one is garbage. (Ponders appropriate degree of scorn but runs out of adjectives.)

Uh huh ?

I picture a small metropolitan garage ….

[ June 10, 2002: Message edited by: echidna ]</p>

liquid

I am familiar with the coanda effect. I think I have heard something about a lenticular aerodyne too, but will have to check to see if it is what I am thinking of.

And the definitions given of the abbreiviations was correct.

The Other Michael

Hi Liquid,

If you like I'll scan an article on Coanda and his aerodyne from a 1950s (or very early 1960s) "FLYING" magazine I have. Send me a PM with your email address if you want that.

You can find some stuff on Coanda's design on the web, but they tend to be on sites about weird Nazi science and conspiracy stuff.

cheers,
Michael

KeithHarwood

Seems to me that a lot of it violates the first law, never mind the second.

However, it is possible that someone, somewhere has heard about the Hilch tube. (I'm not sure of the spelling, Google has never heard of it.) This is a weird device invented in the 1930's that can separate a room temperature air stream into a cold and a hot stream. Basically it is a tube that the air is blown through, creating a vortex. The hot air comes out of the edge of the vortex and the cold air out of the middle (IIRC). It doesn't violate the 2LoT, though; the incoming air must be at a very high pressure, providing the energy that drives the separation. I've seen a description of how they work, but I didn't understand it; turbulence plays a big role.

You used to be able to get small ones that would be used in an electronics lab for cooling components; shock cooling that is, they are far to inefficient to use just for normal cooling. I think they went out of fashion when the freon spray came in for the same job.

liquid

Michael, I've PMed you.

Well, 2LoT or 1LoT makes little difference! I was concentrating on energy transfers within the machine and their irreversibilities, but I suppose for completeness I should have mentioned the 1st.

Hilch tube sounds v. interesting. Haven't heard of it before, although I've got a couple of guesses as to how it might work. Suprised it isn't more popular with the free energy chaps...

KeithHarwood

Turns out the proper spelling is Hilsch, but Google has still never heard of it. More details, high pressure air blown tangentially into narrow bore tube, form vortex, cold at centre, hot at periphery, vanes can separate the streams, hot up to 200C, cold to -50C. As of late 50's, process is one of turbulent transfer but some details unknown. Encyclopedic Dictionary of Physics, ed. Thewlis, V.3?, p.701.

As for the free energy chaps, they'd have to have a sodding great compressor on stage and then convince the marks that it wasn't providing the energy.

liquid

Here I was thinking of some small gas canister!

KeithHarwood

From what I can gather we are talking Seriously High Pressure, even if the total volume of air isn't a lot. I've seen a photograph of one the size of a pencil and it had its own compressor.