[Prev][Next][Index][Thread]
Re: (meteorobs) OT: Supersonic aircraft engineering
In a message dated 12/8/00 12:02:42 PM Pacific Standard Time,
bedient@amsmeteors.org writes:
<<
>The (sharp) leading edges of the SR-71 and possibly other very high speed
>aircraft were made of fairly thick titanium. They did get quite hot in high
>speed flight and stayed hot even for a short while after landing. I don't
>know if there was any cooling system for those leading edges such as
>circulating fuel through them (or a better coolant).
>>
Thanks for the Concorde and SR-71 info Jim. A thought has occurred to me when
folks talk about an aircraft upon landing or a meteorite upon landing is "Too
hot to touch". What exactly "is" too hot to touch? If I put my hand under my
faucet of hot water out of my tap, I probably wouldn't keep it there too
long. Probably would consider it "too hot to touch" too. I keep my hot water
heater thermostat set at 120 Deg F. People have been known to get scalded to
death at this temp. I recall two incidences in this county alone in the last
3 years. So if I touched a meteorite right after landing and I felt a
temperature near 120-150 deg F(normal hot water heater settings around here),
I'd probably claim it was too hot to touch. Probably a reasonable temperature
that could be achieved on some occasions from friction/air compression means
during free fall. But a temp of 120-150 deg F isn't hot enough to start a
fire with ordinary combustibles, such as paper or dried grass. I believe the
ignition temperature for paper and dried grass would be in the neighborhood
of 400 Deg F. So without a spark, you don't have a prayer to start a fire. A
ball sized meteorite sitting on paper or grass at 120-150 deg F, wouldn't get
a fire going. But to a human, it would feel "too hot to touch" in generic
terms....unless there were some other physical characteristics that would
indicate hotter temperatures....such as glowing white hot on the ground or
something.
GeoZay
To UNSUBSCRIBE from the 'meteorobs' email list, use the Web form at:
http://www.tiacdot net/users/lewkaren/meteorobs/subscribe.html