WOLFRAM SYSTEM MODELER

# sharpEdgedOrifice

Return pressure loss data for sharp edged orifice (for both flow directions)

# Wolfram Language

In[1]:=
`SystemModel["Modelica.Fluid.Fittings.BaseClasses.QuadraticTurbulent.LossFactorData.sharpEdgedOrifice"]`
Out[1]:=

# Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

Loss factor for mass flow rate from port_a to port_b (Idelchik 1994, diagram 4-14, p. 221):

```zeta = [(1-A0/A1) + 0.707*(1-A0/A1)^0.375]^2*(A1/A0)^2
for Re(A0) ≥ 1e5,  independent of alpha
```

Loss factor for mass flow rate from port_b to port_a (Idelchik 1994, diagram 4-13, p. 220, with A2=A1):

```zeta = k*(1 - A0/A1)^0.75 + (1 - A0/A1)^2 + 2*sqrt(k*(1-A0/A1)^0.375) + (1- A0/A1)
k  = 0.13 + 0.34*10^(-(3.4*LD+88.4*LD^2.3))
(there is a typing error in the formula in diagram 4-13, the above
equation corresponds to table (a) in diagram 4-12)
LD = L/D0
for Re(A0) ≥ 1e4, 40 deg ≤ alpha ≤ 60 deg
for other values of alpha, k is given as table
in diagram 3-7 (this is not yet included in the function)
```

# Syntax

data = sharpEdgedOrifice(diameter, leastDiameter, length, alpha)

# Inputs (4)

diameter Type: Diameter (m) Description: Inner diameter of pipe (= same at port_a and port_b) Type: Diameter (m) Description: Smallest diameter of orifice Type: Diameter (m) Description: Length of orifice Type: Angle_deg (°) Description: Angle of orifice

# Outputs (1)

data Type: LossFactorData Description: Pressure loss factors for both flow directions