next up previous contents index
Next: 2.3.3 CO5BOLD equation of Up: 2.3 A collection of Previous: 2.3.1 Basic thermodynamic equations   Contents   Index

2.3.2 Definition of often-used thermodynamic coefficients

Definition of specific heats:
\begin{displaymath}
c_p \equiv \left(\frac{\partial h}{\partial T}\right)_{p} = ...
...ight)_{p} = \left(\frac{\partial s}{\partial \ln T}\right)_{p}
\end{displaymath} (27)


\begin{displaymath}
c_v \equiv \left(\frac{\partial e}{\partial T}\right)_{\rho}...
...{\rho} = \left(\frac{\partial s}{\partial \ln T}\right)_{\rho}
\end{displaymath} (28)

Definitions of further thermodynamic coefficients:
\begin{displaymath}
\chi_{T} \equiv \left(\frac{\partial \ln p}{\partial \ln T}\right)_{\rho}
\end{displaymath} (29)


\begin{displaymath}
\chi_{\rho} \equiv \left(\frac{\partial \ln p}{\partial \ln \rho}\right)_{T} \equiv (K p)^{-1}
\end{displaymath} (30)


\begin{displaymath}
\delta \equiv -\left(\frac{\partial \ln \rho}{\partial \ln T}\right)_{p} \equiv \alpha T
= \frac{\chi_{T}}{\chi_{\rho}}
\end{displaymath} (31)

It can be shown that
\begin{displaymath}
c_p - c_v = \alpha^2 T / (K \rho) = \frac{p}{\rho T}  \delt...
...\delta  \chi_{T}
= \frac{p}{\rho T}  \chi_{T}^2/\chi_{\rho}
\end{displaymath} (32)

Definition of adiabatic exponents:
\begin{displaymath}
\Gamma_1 \equiv \left(\frac{\partial \ln p}{\partial \ln \rho}\right)_{s}
\end{displaymath} (33)


\begin{displaymath}
\Gamma_3 \equiv \left(\frac{\partial \ln T}{\partial \ln \rho}\right)_{s} + 1
\end{displaymath} (34)


\begin{displaymath}
\nabla_{\rm ad} \equiv \left(\frac{\partial \ln T}{\partial \ln p}\right)_{s}
\equiv \frac{\Gamma_2-1}{\Gamma_2}
\end{displaymath} (35)


next up previous contents index
Next: 2.3.3 CO5BOLD equation of Up: 2.3 A collection of Previous: 2.3.1 Basic thermodynamic equations   Contents   Index