From: Jhumki Basu (sjbasu@hotmail.com)
Date: Sat Mar 03 2001 - 15:38:06 PST
From: "Jhumki Basu" <sjbasu@hotmail.com> Subject: Re: pinhole Watch an f-14 break the sound barrier Date: Sat, 03 Mar 2001 15:38:06 Message-ID: <F213s4FhIXItgiOM0aE00003b12@hotmail.com>
My cousin, who is an astrophysicist, wrote the paragraphs below about Paul's
explanation of the vapor in the shock waves. I don't understand what he
wrote. Any comments?
Jhumki
>the explanation confuses me. clouds are basically liquid water droplets
>condensed on atmospheric impurities. liquid water becomes vapor when it's
>internal pressure becomes greater or equal to the atmospheric pressure.
>Since the pressure is much lower on the inside of the shock boundary, the
>water droplets should vaporize i.e. no clouds on the inside of the shock.
>on the other hand, i believe this has more to do with the density gradient
>across the shock.
>for an ideal gas: pv=nrt or p = rho*R*T/m where m is the mean mol. weight
>so the ratio p/rho affects the temperature. at the shock front, rho
>increases much more rapidly than p which implies a rapid drop in
>temperature resulting in condensation forming since the air is saturated.
>Inside the shock front, the air is hotter and the pressure is lower so the
>cloud would rapidly dissipate after the aircraft has gone through.
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This archive was generated by hypermail 2b29 : Tue Oct 16 2001 - 12:22:18 PDT