Package Modelica.​Fluid.​Valves.​BaseClasses.​ValveCharacteristics
Functions for valve characteristics

Information

This icon shall be used for a package/library that contains several variants of one component.

Extends from Modelica.​Icons.​VariantsPackage (Icon for package containing variants).

Package Contents

Partial Function Modelica.​Fluid.​Valves.​BaseClasses.​ValveCharacteristics.​baseFun
Base class for valve characteristics

Information

This is a partial function that defines the interface of valve characteristics. The function returns "rc = valveCharacteristic" as function of the opening "pos" (in the range 0..1):

    dp = (zeta_TOT/2) * rho * velocity^2
m_flow =    sqrt(2/zeta_TOT) * Av * sqrt(rho * dp)
m_flow = valveCharacteristic * Av * sqrt(rho * dp)
m_flow =                  rc * Av * sqrt(rho * dp)

Extends from Modelica.​Icons.​Function (Icon for functions).

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Function Modelica.​Fluid.​Valves.​BaseClasses.​ValveCharacteristics.​linear
Linear characteristic

Information

This is a partial function that defines the interface of valve characteristics. The function returns "rc = valveCharacteristic" as function of the opening "pos" (in the range 0..1):

    dp = (zeta_TOT/2) * rho * velocity^2
m_flow =    sqrt(2/zeta_TOT) * Av * sqrt(rho * dp)
m_flow = valveCharacteristic * Av * sqrt(rho * dp)
m_flow =                  rc * Av * sqrt(rho * dp)

Extends from Modelica.​Fluid.​Valves.​BaseClasses.​ValveCharacteristics.​baseFun (Base class for valve characteristics).

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Function Modelica.​Fluid.​Valves.​BaseClasses.​ValveCharacteristics.​one
Constant characteristic

Information

This is a partial function that defines the interface of valve characteristics. The function returns "rc = valveCharacteristic" as function of the opening "pos" (in the range 0..1):

    dp = (zeta_TOT/2) * rho * velocity^2
m_flow =    sqrt(2/zeta_TOT) * Av * sqrt(rho * dp)
m_flow = valveCharacteristic * Av * sqrt(rho * dp)
m_flow =                  rc * Av * sqrt(rho * dp)

Extends from Modelica.​Fluid.​Valves.​BaseClasses.​ValveCharacteristics.​baseFun (Base class for valve characteristics).

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Function Modelica.​Fluid.​Valves.​BaseClasses.​ValveCharacteristics.​quadratic
Quadratic characteristic

Information

This is a partial function that defines the interface of valve characteristics. The function returns "rc = valveCharacteristic" as function of the opening "pos" (in the range 0..1):

    dp = (zeta_TOT/2) * rho * velocity^2
m_flow =    sqrt(2/zeta_TOT) * Av * sqrt(rho * dp)
m_flow = valveCharacteristic * Av * sqrt(rho * dp)
m_flow =                  rc * Av * sqrt(rho * dp)

Extends from Modelica.​Fluid.​Valves.​BaseClasses.​ValveCharacteristics.​baseFun (Base class for valve characteristics).

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Function Modelica.​Fluid.​Valves.​BaseClasses.​ValveCharacteristics.​equalPercentage
Equal percentage characteristic

Information

This characteristic is such that the relative change of the flow coefficient is proportional to the change in the opening position:

d(rc)/d(pos) = k d(pos).

The constant k is expressed in terms of the rangeability, i.e., the ratio between the maximum and the minimum useful flow coefficient:

rangeability = exp(k) = rc(1.0)/rc(0.0).

The theoretical characteristic has a non-zero opening when pos = 0; the implemented characteristic is modified so that the valve closes linearly when pos < delta.

Extends from Modelica.​Fluid.​Valves.​BaseClasses.​ValveCharacteristics.​baseFun (Base class for valve characteristics).

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