Frankly, I'm a "Bird, Stewart and Lightfooot" man my myself.
> ----------
> From: Edward Szpruch[SMTP:[log in to unmask]]
> Reply To: TechNet E-Mail Forum.
> Sent: Tuesday, November 13, 2001 4:48 AM
> To: [log in to unmask]
> Subject: Re: [TN] Formula?
>
> Gentelmen,
> All those,who are graduated in chemical engineering are kindly asked to
> open
> their old tekstbooks on "Heat,Momentum and Mass Transfer" ( 3rd,4th and
> 5th
> semester in faculties of chemical engineering).Basic books used to be
> McCabe-Smith and W.W.W. ( Whelty + 2 other with W ) .At least those were
> my
> books more than 30 years ago.
>
>
> Edward Szpruch
> Eltek Ltd
> P.O.Box 159 ; 49101 Petah Tikva Israel
> Tel ++972 3 9395050 , Fax ++972 3 9309581
> e-mail [log in to unmask]
>
> > -----Original Message-----
> > From: Rummy Makmur [SMTP:[log in to unmask]]
> > Sent: ג נובמבר 13 2001 14:12
> > To: [log in to unmask]
> > Subject: Re: [TN] Formula?
> >
> > To prove that, you need combination of mass balance and mechanical
> energy
> > balance (i.e. bernoulli equation).
> >
> > mass balance: mass rate in = mass rate out. Assuming incompressible
> fluid
> > (same density in and out), since mass rate = volume rate * density,
> > density
> > get canceled out and the result is volume rate in = volume rate out. It
> is
> > also known that volume rate = velocity * Area. From this you can prove
> > that,
> > if area is decreased (such as, putting your thumb on the hose), velocity
> > will increase.
> >
> > Then you will need bernouli equation. Simplified Bernoulli Equation:
> > (P1/density) + (Velocity1^2/2)+ (gh1) = (P2/density) + (velocity2 ^ 2/
> 2)
> > +
> > (gh2)
> >
> > Assuming h (height) is the same, they get canceled out. Then, you will
> > have
> > an equation with only P (Pressure) and V (velocity) as variables which
> you
> > can use to prove that if V2 increases, P2 decreases, provided P1 and V1
> > are
> > constant.
> >
> > So, volume rate at location 2 is not dependent on Pressure at location
> 2,
> > provided same pressure and volume rate coming in. It "feels" like
> pressure
> > increasing, but rather it's velocity that is increasing or kinetic
> energy
> > increases.
> >
> > Check out these sites
> > http://physics.bu.edu/py105/notes/Bernoulli.html
> > http://rabi.phys.virginia.edu/HTW/water_distribution.html
> >
> > For the second question, you might not be able to use same exact
> equations
> > for air, since air might be considered as compressible. It may involve
> > more
> > complicated equations.
> >
> > Rummy Makmur
> > Process Engineer
> > Ibiden Circuits of America
> >
> > -----Original Message-----
> > From: Eric Christison [mailto:[log in to unmask]]
> > Sent: Tuesday, November 13, 2001 3:27 AM
> > To: [log in to unmask]
> > Subject: Re: [TN] Formula?
> >
> >
> > I think you're all barking up the wrong tree.
> >
> > Bernoulli's equations shows the conservation of kinetic energy in fluids
> > and is generally used to calculate things like areodynamic lift on an
> > aerofoil or the forces exerted on a pipe wall as the the contents flows
> > round a corner.
> >
> > I think you're searching for P1v1/T1 = P2v2/T2. However v is not volume
> > but specific volume ie m^3/Kg.
> >
> > Spend a minute on a reality check. If you put your thumb on the end of a
> > hose pipe does the pipe get smaller? If not, how can the volume of the
> > pipe decrease?
> >
> > Hope this helps,
> >
> >
> >
> > [log in to unmask] wrote:
> > >
> > > Ray, try http://www.lmnoeng.com/Flow/bernoulli.htm
> > >
> > > -----Original Message-----
> > > From: TechNet [mailto:[log in to unmask]]On Behalf Of Golembiewski, Ray
> > > Sent: Monday, November 12, 2001 14:34
> > > To: [log in to unmask]
> > > Subject: [TN] Formula?
> > >
> > > What is the formula that proves when I put my thumb on the end
> > > of a garden house, the pressure increases and volume decreases. Is the
> > > same formula used with air? Please help,
> > >
> > > Ray Golembiewski C.I.D.
> > > Manufacturing Test Engineer
> > > Projects Unlimited, Inc.
> > > (937) 918-2200
> > >
> > --
> > Eric Christison
> > Mechanical Engineer
> > STMicroelectronics
> > 33 Pinkhill
> > Edinburgh
> > EH12 7BF
> >
> > Tel: (0)131 336 6165
> > Fax: (0)131 336 6001
> >
> >
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