bConverged

Contraction

Next: Enlargement Up: Fluid Section Types: Open Previous: Reservoir Contents

Contraction

**Figure 86:** Geometry of a contraction
$\begin{figure}\epsfig{file=Channelcontraction.eps,width=9cm}\end{figure}$

The geometry of a contraction is shown in Figure 86 (view from above). Although a contraction is really a discontinuity, a small fictitious length an a slope have to be assigned. For the slope one can take the mean values of the slopes of the adjacent channels. The following constants have to be specified on the line beneath the *FLUID SECTION,TYPE=CHANNEL CONTRACTION card:

the upstream width
the slope (if zero is taken)
the length (if $L \le 0$ the length is calculated from the coordinates of the end nodes belonging to the element)
the downstream width $b_2 \le b_1$

Example files: channel9, channel11.

guido dhondt 2011-03-26