RussellMc <apptechnz <at> gmail.com> writes:

>=20
> > > "Rate" may mean volume per second or velocity. The former is more
> > > rigorous but the latter not unknown.
>=20
> > Linear velocity, at least for pipe flow is a non-descriptive term by it=
self.
>=20
> Och aye!
> That was embodied in  " ... the former is more rigorous ... " along
> with a few other things as well=20
<SNIP>
> If you use eg a "propellor" for velocity measurement it will add it's
> own "law" to what it tells you and you'll probably need a custom form
> of weed to be sure of getting it right as eg depth varies, prop dia
> other than full pipe dia leads to differences, fluid density may
> matter, entrained solids too, ... .
>=20
Next time I need flow measurement I will ask you for the custom weed form. =
 Last
year I was involved in a project where the "pipe" was 100 micron tube.  We
measured flow optically, by tracking suspended particles (about 1 micron
diameter), and by NMR (nuclear magnetic resonance).  I did not think NMR wo=
uld
be applicable to the OP question.  Need some pretty uniform magnets and hig=
hly
specialized (read expensive) electronics.  IIRC, frequency shift of NMR sig=
nal
was <10 Hz with center frequency about 70 MHz. =20

During the project I also saw a nice demonstration of "newtonianness" of
different liquids: e.g. water - newtonian, blood - not.

Sergey Dryga
http://beaglerobotics.com



--=20
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