Laminar Leakage (IL)
A block that simulates laminar flow through sections of various geometries in an isothermal fluid network.
blockType: AcausalFoundation.IsothermalLiquid.Elements.LaminarLeakage
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Description
Block Laminar Leakage (IL) simulates laminar flow in isothermal liquid networks. The block includes several common flow geometries, as well as custom geometries. Select the value of the Cross-sectional geometry parameter, and then specify the values of the other element parameters based on the selected parameter.:
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Circular(circle) — diameter and length. -
Annular(ring) — inner diameter, outer diameter and length. -
Rectangular(rectangle) — width, height, and length. -
Elliptical(ellipse) — the major axis, the minor axis, and the length. -
Equilateral triangular(equilateral triangle) — the side of the triangle and the length. -
Custom(custom geometry) — Specify the hydraulic resistance value, i.e. the ratio of pressure loss to mass flow. In this configuration, the unit simulates linear hydraulic resistance.
The flow calculations are based on the Hagen-Poiseuille equation, which is valid for laminar flow:
where:
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— mass flow through port A.
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and — pressure at ports A and B respectively.
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— the coefficient calculated based on the geometry of the cross section.
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— the diameter of the circular section.
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— the outer diameter of the annular section.
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— the inner diameter of the annular section.
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— the width of the rectangular section.
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— the height of the rectangular section.
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— the large axis of the elliptical section.
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— the minor axis of the elliptical section.
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— the length of the side of the triangular section.
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— length.
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— linear hydraulic resistance for custom geometry.
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— kinematic viscosity of a liquid at atmospheric pressure; a global parameter determined by the block Isothermal Liquid Properties (IL), connected to the model.
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— the average density of the liquid mixture.
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and — the density values of the liquid mixture at ports A and B, respectively. The equations used to calculate the density of a liquid mixture depend on the selected isothermal fluid model.
Ports
Non-directional
A — inlet or outlet
isothermal liquid
The isothermal fluid port corresponds to the inlet or outlet of a laminar leak. This block has no internal orientation.
B — inlet or outlet
isothermal liquid
The isothermal fluid port corresponds to the inlet or outlet of a laminar leak. This block has no internal orientation.
Parameters
Cross-sectional geometry — cross-sectional shape of the leak
Circular (by default) | Annular | Rectangular | Elliptical | Equilateral triangular | Custom
Select the cross-sectional shape, and then set the values of the other parameters based on the selected option.
Diameter — diameter of the circular cross-section of the
1e−3M (default)
The diameter of the circular section.
Dependencies
Enabled when the Cross-sectional geometry parameter has the value Circular.
Inner diameter — the inner diameter of the annular section of the
5e−4M (default)
The inner diameter of the annular section.
Dependencies
Available when the Cross-sectional geometry parameter has the value Annular.
Outer diameter — the outer diameter of the annular section of the
1e−3M (default)
The outer diameter of the annular section.
Dependencies
Available when the Cross-sectional geometry parameter has the value Annular.
Width — the width of the rectangular section of the
1e−3M (default)
The width of the rectangular section.
Dependencies
Available when the Cross-sectional geometry parameter has the value Rectangular.
Height — the height of the rectangular section of the
0.1 m (default)
The height of the rectangular section.
Dependencies
Available when the Cross-sectional geometry parameter has the value Rectangular.
Major axis — the major axis of the elliptical cross section of
1e−3M (default)
The major axis of the elliptical cross section.
Dependencies
Available when the Cross-sectional geometry parameter has the value Elliptical.
Minor axis is the minor axis of the elliptical cross section of
5e−4M (default)
The minor axis of the elliptical cross section.
Dependencies
Available when the Cross-sectional geometry parameter has the value Elliptical.
Side length — the length of the side of a triangle for an equilateral triangular section
1e−3M (default)
The length of the side of a triangle for an equilateral triangular section.
Dependencies
Available when the Cross-sectional geometry parameter has the value Equilateral triangular.
Longitudinal length — pass length:q[<br>] 5 m (default)
The length of the leakage channel.
Linear pressure-flow resistance — ratio of pressure loss to volume flow
1e3 s·MPa/m3 (default)
The ratio of pressure loss to volume flow. If the geometry of the cross-section is unknown, the block acts as a linear hydraulic resistance.
Dependencies
Available when the Cross-sectional geometry parameter has the value Custom.