A diaphragm (Figure 115) is characterized by head losses of the form:
where is a head loss coefficient depending on the ratio , is the mass flow, g is the gravity acceleration and is the liquid density. and are the cross section of the diaphragm and of the pipe, respectively. Values for can be found in file “liquidpipe.f”.
The following constants have to be specified on the line beneath the *FLUID SECTION, TYPE=PIPE DIAPHRAGM card:
The gravity acceleration must be specified by a gravity type *DLOAD card defined for the elements at stake. The material characteristic can be defined by a *DENSITY card.