Re: [boost] [units]

From: Michael Fawcett (michael.fawcett_at_[hidden])
Date: 2007-03-07 11:36:27

On 3/6/07, Deane Yang <deane_yang_at_[hidden]> wrote:
> Noah Roberts wrote:
> > Deane Yang wrote:
> >> Can you provide a concrete example?
> >
> > Formula for Fluid Compressibility through a Venturi Tube:
> >
> > Y = {[kt^(2/k)/(k-1)][(1-b^4)/(1-b^4t^(2/k))][(1-t^((k-1)/k)/(1-t)]}^.5
> >
> > With k being the SP heat ratio of the fluid passing through the venturi.
> >   Static dimensional analysis is impossible here.  In fact dimensional
> > analysis at all just isn't appropriate in these odd cases.
> >
>
> So you're saying that the dimension/unit library does *not* need to
> worry about formulas like this, right? If so, my comments below are
> off-topic.
>
> But I'm still a skeptic. I don't see why the trick I outlined before
> can't be played here, too. Tell me what each variable means and what
> units it is in (if any). Or give me an online reference for this formula.

It appears that he's referring to the equation given here:

http://en.wikipedia.org/wiki/Orifice_plate

Look for the equation under the heading "Flow of gases through an
orifice".  Above it and below it are references to the variable units.

--Michael Fawcett