Fluxes through surface element
with normal vector
:
Mass transport
change of mass per time:
 |
(8) |
Momentum transport and acceleration by pressure force along surface normal
change of momentum per time
![\begin{displaymath}
\left[ \rho \ensuremath{\mathchoice{\mbox{\boldmath$\dis...
...$}}
{\mbox{\boldmath$\scriptscriptstyle n$}}}} \right] \; d\!A
\end{displaymath}](img35.png) |
(9) |
Energy transport and work done by pressure
change of total energy per time
![\begin{displaymath}
\left[ \rho e_{\rm ik}+ P\right] \ensuremath{\mathchoice{\m...
...tstyle n$}}
{\mbox{\boldmath$\scriptscriptstyle n$}}}} \; d\!A
\end{displaymath}](img36.png) |
(10) |
Shear forces (friction) are ignored.
There are no torsional forces (only relevant in solids).