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The Equation of State

The equation of state gives a relationship between the pressure, density and temperature. It can take several different forms depending of the situation being modelled. For example, when considering a uniform incompressible fluid it is simply
\begin{displaymath}
\rho = \hbox{ constant}.
\end{displaymath} (2.10)

For a perfect gas, it is
\begin{displaymath}
p = \rho {R} T,
\end{displaymath} (2.11)

where ${R} = 8.3 \times 10^{3}$ is the gas constant, so that the pressure proportional to both the density and temperature. The temperature must then be given by an energy equation (or specified as a constant).

Prof. Alan Hood
2000-11-06