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From: henry@zoo.toronto.edu (Henry Spencer)
Newsgroups: sci.military
Subject: Re: Aircraft shock waves
Message-ID: <1991Apr23.053857.24039@amd.com>
Date: 23 Apr 91 00:38:51 GMT
References: <1991Apr22.071716.24851@amd.com>
Sender: military@amd.com
Organization: U of Toronto Zoology
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From: henry@zoo.toronto.edu (Henry Spencer)


>From: Tony_Buckland@mtsg.ubc.ca
>Fiction and some fact literature talks about the ground and shipboard
>damage that can be caused by supersonic or hypersonic aircraft at low
>altitudes.  But where is all the energy coming from? ...

	[Don't start paragraph's with From, please! 
	 It fools the digesting software into thinking 
	 its a mail header. --CDR]

[F]rom the aircraft's engines.  Those shock waves represent huge amounts
of drag; the engines have to push both the aircraft and the shock waves
through the air.

>... Is this energy really
>sufficient to leave a trail of destruction across hundreds or thousands
>of km of the Earth's surface?

If it's a sufficiently powerful engine, yes.  The Pluto cruise missile
(would have) had a one-gigawatt reactor driving it.  Conventional jet
engines run out of fuel very quickly at max power, and consequently
conventional jet aircraft spend little or no time at supersonic speeds
(let alone Pluto's Mach 3!) at low altitude.
-- 
And the bean-counter replied,           | Henry Spencer @ U of Toronto Zoology
"beans are more important".             |  henry@zoo.toronto.edu  utzoo!henry