A entrance (Figure 101) is characterized by head
losses 
![]() of the form:
 of the form:
|  | (83) | 
where ![]() is a head loss coefficient depending on the ratio
 is a head loss coefficient depending on the ratio ![]() ,
,
![]() is the mass flow, g is the gravity acceleration and
 is the mass flow, g is the gravity acceleration and ![]() is the
liquid density.
 is the
liquid density. ![]() and
 and ![]() are the cross section of the entrance and of
the pipe, respectively. Values for
 are the cross section of the entrance and of
the pipe, respectively. Values for ![]() can be found in file ``liquidpipe.f''.
 can be found in file ``liquidpipe.f''.   
The following constants have to be specified on the line beneath the *FLUID SECTION, TYPE=PIPE ENTRANCE 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.
 can be defined by a
*DENSITY
card. 
Example files: pipe, piperestrictor.