Pipe Properties
The Pipe Properties node is used to define the pipe shape, flow resistance, and surface roughness.
Pipe Shape
Select a pipe shape from the list — Not set (the default), Circular, Square, Rectangular, Concentric circular annular, or User defined.
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For Circular enter a value or expression for the Inner diameter di (SI unit: m). The default is 10 cm.
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For Square enter a value or expression for the Inner width wi (SI unit: m). The default is 5 cm.
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For Rectangular enter a value or expression for the Inner width wi (SI unit: m. The default is 5 cm) and Inner height hi (SI unit: m. The default is 10 cm).
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For Concentric circular annular enter a value or expression for the Inner diameter, outer pipe di,outer (SI unit: m. The default is 10 cm) and Outer diameter, inner pipe do, inner(SI unit: m. The default is 0 cm).
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For User defined enter a value or expression for the Cross-sectional area Ac (SI unit: m2). The default is 0.01 m2. Enter the Wetted perimeter Z (SI unit: m). The default is 0.4 m.
Flow Resistance
Select a Friction model.
Newtonian Fluids
Select Churchill (the default), Stokes, Wood, Haaland, Colebrook, Von Karman, Swamee-Jain, or User defined.
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For Churchill, Wood, Haaland, Von Karman, or Swamee-Jain go to the Surface Roughness section to select from a list of predefined values. Alternatively, enter values or expressions.
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For User defined enter a value or expression for the Darcy friction factor fD (dimensionless).
Non-Newtonian Fluids
For Power-law and Bingham fluids in tubes of circular cross section, the Irvine, Stokes, and Darby friction models are available.
For more information about the friction models, see Expressions for the Darcy Friction Factor.
Surface Roughness
This section is available if Churchill, Wood, Haaland, Von Karman, or Swamee-Jain is selected as the Friction model.
Select a Surface roughness from the list — Smooth (0 mm), Drawn tubing (0.0015 mm) (the default), Glass (0.0015 mm), Thermoplastics (0.0015 mm), Commercial steel (0.046 mm), Wrought iron (0.046 mm), Steel welded seamless (0.061 mm), Asphalted cast iron (0.12 mm), Galvanized iron (0.15 mm), Cast iron (0.26 mm), Wood stave (0.5 mm), Copper and brass (0.61 mm), Concrete (1.5 mm), Riveted steel (4.5 mm), or User defined.
For User defined enter a value or expression for the Roughness (SI unit: m).