bConverged

Restrictor, Bend

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Restrictor, Bend

**Figure 62:** Geometry of a bend
$\begin{figure}\epsfig{file=Bendgas.eps,width=11cm}\end{figure}$

The geometry of a bend is shown in Figure 62. There are three types: TYPE = RESTRICTOR BEND IDEL CIRC, TYPE = RESTRICTOR BEND IDEL RECT, both with loss coefficients according to [28] and TYPE = RESTRICTOR BEND MILLER with coefficients taken from [46]. In the first and last type the bend is described by the following constants (to be specified in that order on the line beneath the *FLUID SECTION, TYPE = RESTRICTOR BEND IDEL CIRC or TYPE = RESTRICTOR BEND MILLER card):

cross section before the bend .
cross section after the bend .
hydraulic diameter .
radius of the bend .
bend angle $\alpha$ .
oil mass flow in the restrictor (only if the OIL parameter is used to define the kind of oil in the *FLUID SECTION card)

They apply to circular cross sections. For rectangular cross sections the constants are as follows (to be specified in that order on the line beneath the *FLUID SECTION, TYPE=RESTRICTOR BEND IDEL RECT card):

cross section before the bend .
cross section after the bend .
hydraulic diameter .
radius of the bend .
bend angle $\alpha$ .
height .
width .
oil mass flow in the restrictor (only if the OIL parameter is used to define the kind of oil in the *FLUID SECTION card)

The loss coefficients are those published by Idelchik [28] and Miller [46].

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: restrictor, restrictor-oil.

Next: Restrictor, Wall Orifice Up: Fluid Section Types: Gases Previous: Restrictor, Contraction Contents

guido dhondt 2011-03-26