[Vwdiesel] PV=nRT and Hydraulics

[H.Hagar]

----- Original Message -----
From: "H.Hagar" <h_hagar at prcn.org>
To: <vwdiesel at vwfans.com
Sent: Wednesday, July 21, 2004 10:33 AM
Subject: PV=nRT and Hydraulics


>
> ----- Original Message -----
> From: "Val Christian" <val at swamps.roc.ny.us>
> To: <vwdiesel at vwfans.com>
> Sent: Wednesday, July 21, 2004 10:24 AM
> Subject: PV=nRT and Hydraulics
>
>
> > You'll recall the ideal gas law, PV=nRT.
> >
> > You'll also recall that release of gas pressure will cause cooling.
Works
> > with a rapidly decompressing gas cylinder, such as an O2 cylinder on a
> cutting
> > torch.  Or a CO2 fire extinquisher.
> >
> > n stands for the moles of gas in the system,
> >
> > R is a constant, which is emphirically derived.  It can be thought of as
> > the compressibility of the gas.
> >
> > I believe the gas law applies to fluids, such as water, hydraulic fluid
> > and diesel fuel.  R is just real small.
> >
> > This would suggest that in theory, the release of pressure on a
hydraulic
> > line would cause a decrease in temperature.  A quick consult with my
> > physical chemistry experts confirms this.  [Liquid exceptions exist, and
> > include water (4C to 0C), ATF in some pressure and temperature domains,
> > etc.]  The compressibility of simple compounds is found in references
such
> > as CRC.
> >
> > Soooo, Lee, in theory, that leakage past the pump should cause COOLING,
> > rather than heating.  I rest on my earlier assertion that the heat in
> > the pump is primarily from losses due to turbulent flow, fluid friction
> > and the like.
> >
> > Val
> >
>