Why do jets leave a white trail behind them.

"Jim Macklin" wrote in message
news:jbWzf.66478$QW2.21900@dukeread08...
It is hydroscopic and absorbs water. The water in the
"spaces" between the hydrocarbon is where the fungus grows.
\\
Damn spell checker. Hydroscopic prollly was not a choice. G
--
Jim in NC

Jim Macklin wrote:

It is hydroscopic and absorbs water. The water in the
"spaces" between the hydrocarbon is where the fungus grows.

I still believe that the water contained in the fuel is a small part of
the water contained in the exhaust that is formed when the hydrocarbon
is combusted.


Matt

"Matt Whiting" wrote

If jet fuel is full of water, how do you get it to burn? When I took
chemistry, hydrocarbon fuels contained .... drum roll please ... carbon
and hydrogen. No water of any level of significance.
\\
Combustion leaves some hydrogen unclaimed, and the oxygen is really happy to
claim it, and when it combines two H's, and one O, you get water.

Weren't awake during that day of chemistry, were you, Matt? g
--
Jim in NC

Morgans wrote:


"Matt Whiting" wrote

If jet fuel is full of water, how do you get it to burn? When I took
chemistry, hydrocarbon fuels contained .... drum roll please ...
carbon and hydrogen. No water of any level of significance.

\\
Combustion leaves some hydrogen unclaimed, and the oxygen is really
happy to claim it, and when it combines two H's, and one O, you get water.

Weren't awake during that day of chemistry, were you, Matt? g

That was my point precisely. The water isn't IN the fuel. It is formed
by the fuel and the oxygen in the air via the combustion process. That
isn't at all the same as saying that the water is IN the fuel.


Matt

You guys really need a refresher course in chemistry. When hydrocarbons
burn, the Hydrogen atoms are split off of the carbon. The hydrogen then
combines with Oxygen forming water. The carbon combines with Oxygen to form
CO2. All of this creates lots of heat. There is no "unclaimed" hydrogen.

Also, normal fuel is NOT hydroscopic. Water and fuel don't mix. That's why
you drain it out of the sumps. The water occurs in fuel tanks from
condensation from air in the tanks. It then settles to the bottom of the
tank, as it is heavier than fuel. If there is any significant amount of
water in the fuel, you've got very BIG problems (either your trying to burn
pure water, or you've got frozen fuel lines).

As a side note, some aircraft engines have used water injection as a method
to increase power output during takeoffs.

Mike Schumann

"Morgans" wrote in message
...

"Matt Whiting" wrote

If jet fuel is full of water, how do you get it to burn? When I took
chemistry, hydrocarbon fuels contained .... drum roll please ... carbon
and hydrogen. No water of any level of significance.
\\
Combustion leaves some hydrogen unclaimed, and the oxygen is really happy
to claim it, and when it combines two H's, and one O, you get water.

Weren't awake during that day of chemistry, were you, Matt? g
--
Jim in NC

Matt Whiting wrote in news:n1Vzf.5348$lb.461860
@news1.epix.net:

Jim Macklin wrote:

Jet fuel also contains a lot (relatively) of water, which
condenses soon after leaving the exhaust. That is why they
are called CONTRAILS condensation trails. They were first
seen behind the bombers during WWII and so-named.

If jet fuel is full of water, how do you get it to burn? When I took
chemistry, hydrocarbon fuels contained .... drum roll please ... carbon
and hydrogen. No water of any level of significance.

Matt

Others have already explained how there is water diluted in the
fuel, but I think you forgot something. What do you burn that
hydrocarbon with? That's right! O2. When the fuel bruns, some of
that H combines with some of that O2 and you end up with some
H2O.

Brian
--
http://www.skywise711.com - Lasers, Seismology, Astronomy, Skepticism
Seismic FAQ: http://www.skywise711.com/SeismicFAQ/SeismicFAQ.html
Quake "predictions": http://www.skywise711.com/quakes/EQDB/index.html
Sed quis custodiet ipsos Custodes?

"Skywise" wrote in message
...
Others have already explained how there is water diluted in the
fuel, but I think you forgot something. What do you burn that
hydrocarbon with? That's right! O2. When the fuel bruns, some of
that H combines with some of that O2 and you end up with some
H2O.


Nearly all of the H should combine with O2 to make H2O, nearly all of the C
should combine with O2 to make CO2. 95% to 99% would be ball park numbers.
CO goes up as you go rich a lot faster than unburned HC in a piston engine.

Contrails are no different than the white water vapor you see behind cars on
a cold day.

--
Geoff
the sea hawk at wow way d0t com
remove spaces and make the obvious substitutions to reply by mail
Spell checking is left as an excercise for the reader.

"Matt Whiting" wrote in message
...
If jet fuel is full of water, how do you get it to burn? When I took
chemistry, hydrocarbon fuels contained .... drum roll please ... carbon
and hydrogen. No water of any level of significance.

For it to burn, there must be oxygen present, right? And hydrogen and
oxygen give you what?

Grumman-581 wrote:
"Matt Whiting" wrote in message
...

If jet fuel is full of water, how do you get it to burn? When I took
chemistry, hydrocarbon fuels contained .... drum roll please ... carbon
and hydrogen. No water of any level of significance.


For it to burn, there must be oxygen present, right? And hydrogen and
oxygen give you what?

Hint: the oxygen doesn't come from the fuel. Hence the fuel isn't full
of oxygen. The fuel is full of hydrogen. That is only half of what you
need to make water.


Matt

"AliR" wrote in message
om...
Hi everyone,

Me and a friend are wondering why jets leave a white trail behind them.
My
guess is that it's moisture being compressed as it passes through the
turbine (because some leave a single trail, while others leave two
separate
trails). My friend thinks it's because of moisture being cooled as it
passes over the wing (Bernoulli effect).

While flying a bonanza I have seen a small white trail extending from the
wingtip for a little while right after I break through the clouds
(descending).

Is either one of us right?

AliR.


The goobermint is really leaving behind chemtrails to kontrol your brain!
BWHHAAAAAAHAAAAA!!!!

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DW