Re: fluid analogs (erratum)

[David Bowman <dbowman@TIGER.GEORGETOWNCOLLEGE.EDU>]

Oops!  In my last post I wrote:
>  ...                             , then one finds that Poiseuille's
> (sp?) Law gives: R = K*[eta]*L/([rho]*A)^2 , where K is a fixed
> dimensionless proportionality constant that depends on the cross
> section shape of the pipe.  (For a circular cross section we have
> K = 2*[pi] which is also the upper bound that K can have for any shape
> cross section.)              ^^^^^

What I meant to say in the last parenthetical statement was: "For a
circular cross section we have K = 2*[pi] which is also the *LOWER* bound
that K can have for any shape cross section."

I temporarily was thinking about flow conductance while I was writing about
resistance.  If the cross section changes shape from round to some other
shape while the cross section area remains fixed, then the flow resistance
and K increase.

David Bowman
dbowman@georgetowncollege.edu