A bend (Figure 116) is characterized by head losses of the form:
where is a head loss coefficient depending on the bend angle and the ratio of the bend radius to the pipe diameter , is the mass flow, g is the gravity acceleration and is the liquid density. is the cross section of the pipe. 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 BEND card:
denotes the roughness of the pipe: applies to an extremely smooth pipe surface, to a very rough surface. 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.
Example files: centheat1, pipe.