Fw: Fw: Holden Commodore, Aerodynamics. AND NOW: WATER INJECTION...

[Danny Barrett]

G'day there, when I consider the things I've been taught in my physical
chemistry calsses (before college, and during my Engineering degree that I
am currently doing), the water should (I won't say will - I could be wrong)
stay in the liquid phase until after TDC. Look at the formula:

PV=nRT

P=pressure in Pascals
V=volume in m^3
n=amount of a gaseous mixture in moles
R=universal gas constant
T=trmperature in Kelvin.

Also, find a table of the boiling point/Vapor Pressure of water at a given
temperature.

Find your TDC pressure.

Find some value of maximum combustion heat (usually above about 900 deg C,
as NOx gases are produced).

If you know how to use the formula, you'll find that the water should remain
a liquid until well after TDC, even if it started off as a vapor before
compression. Of course, I could be wrong. But I did some calc's about a year
ago, and I found that you need a boiling point of about 40 deg C before a
gaseous substance will stay a gas at TDC. Of course, I will repeat again
that I could be WRONG, so it might still need to be researched.

Danny Barrett.

>Mike:
>
>Yes, I agree ...research project
>
>Timing water phase change requires work.  We all know that the rate of
>evaporation of a liquid dropplet suspended in a gas phase is a function of
>the following variables:  local turbulence, local temperature gradients,
>local pressure surfaces, and dropplet size.  Vaporization is driven by
>fugacities of the gas phase versus the liquid phase.  Experimentation would
>have to be done with both dropplet size and injection temperature.
>
>Wayne Strasser
>Chemical Engineer
>EFI Patent Pending
>