Restrictor, Contraction

Properties: adiabatic, not isentropic, directional, outlet based restrictor

The geometry of a contraction is shown in Figure 95. It is described by the following constants (to be specified in that order on the line beneath the *FLUID SECTION, TYPE=RESTRICTOR CONTRACTION card):

• full cross section .
• reduced cross section .
• hydraulic diameter of the reduced cross section defined by where is the perimeter of the cross section.
• chamfer length .
• chamfer angle ().
• oil mass flow in the restrictor (only if the OIL parameter is used to define the kind of oil in the *FLUID SECTION card)
• not used (internally: oil material number)

The loss coefficient for a contraction is taken from [34].

By specifying the parameter LIQUID on the *FLUID SECTION card the loss is calculated for liquids. In the absence of this parameter, compressible losses are calculated.

Example files: piperestrictor, restrictor, restrictor-oil.