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% Verbal description for system NozzleFlow (NozzleFlow_desc.tex)
% Generated by MTT on Thu Mar 19 13:24:59 GMT 1998.

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   The acausal bond graph of system \textbf{NozzleFlow} is
   displayed in Figure \Ref{NozzleFlow_abg} and its label
   file is listed in Section \Ref{sec:NozzleFlow_lbl}.

This 5 port component computes the mass flow in a polytropic
convergent nozzle from the formula:
\begin{equation}
  \dot m = A p_1 \sqrt{\frac{2n}{n-1}\frac{1}{RT_1} 
   \left ( \frac{p_2}{p_1} \right )^\frac{2}{n}
    \left [ 1- \left ( \frac{p_2}{p_1} \right )^\frac{n-1}{n} \right ]  }
\end{equation}

where:
\begin{itemize}
\item $n$ is the coefficient of polytropic expansion and
\item $R$ is the universal gas constant.
\end{itemize}

If the expansion is isentropic
\begin{equation}
  n=\gamma=\frac{c_p}{c_v}
\end{equation}
whre $c_p$ and $c_v$ are the spesicfic heats at constant pressure and volume.

Typical values for air are 
\begin{equation}
  \begin{align}
    R &= 287 \text{Nm}\text{kg}^{-1}{K}^{-1}\\
    \gamma &= 1.4
  \end{align}
\end{equation}