🚀 go-pugleaf

Keith Williams  <krw@att.bizzzz> writes:

: That vapor condenses as the result of the exhaust pipes being cold,
: not the engine.  It's the same principle as that of contrails: hot
: gases containing water vapor pass into a cold environment, where 
: the vapor condenses.  As more and more warm exhaust passes through 
: the exhaust pipes, they warm up down their length until at some 
: point, no more visible vapor comes out. 

> If that were the case there wouldn't be contrails. 

Why?  The tailpipes of jet engines are proportionately shorter than
those of automobiles, the exhaust gases are much hotter, and the 
surrounding air at altitude is typically much colder than at ground 
level.  Given the greater temperature difference, it makes sense that
high-flying aircraft put out visible water vapor in the form of con-
trails while cars stop putting out visible vapor once their exhaust
systems warm up.  


> The water's not from the intake air, rather a combustion byproduct.

Noted.



Geoff

-- 
"We Meldrick.  Resissance is futile, yo.  Y'all bess juss 'pare t'be
 assimilated." -- Jim Hill