Class ModifiedParabolicCharacteristic

java.lang.Object
neqsim.process.mechanicaldesign.valve.ModifiedParabolicCharacteristic
All Implemented Interfaces:
Serializable, ValveCharacteristic
public class ModifiedParabolicCharacteristic extends Object implements ValveCharacteristic
Represents a valve with a modified parabolic (or parabolic) flow characteristic.

Modified parabolic valves provide a characteristic that falls between linear and equal percentage. At low openings, it behaves more like equal percentage, and at high openings, it approaches linear behavior.

The characteristic follows the equation: 

Cv = Cv_max * x ^ n

where:

  • x = fractional valve opening (0 to 1)
  • n = exponent (default 2.0 for parabolic, can be adjusted)

Modified parabolic valves are used when:

  • A compromise between linear and equal percentage is needed
  • The process has moderate pressure drop variations
  • Butterfly valves (which have inherent parabolic characteristics)
Version:
1.0
Author:
esol
See Also:

  • Field Details

    • serialVersionUID

      private static final long serialVersionUID
      See Also:

    • exponent

      private double exponent
      The exponent for the parabolic curve. Default is 2.0 for standard parabolic. Values between 1.5 and 2.5 are common for modified parabolic characteristics.

  • Constructor Details

    • ModifiedParabolicCharacteristic

      public ModifiedParabolicCharacteristic()
      Default constructor with standard parabolic exponent of 2.0.

    • ModifiedParabolicCharacteristic

      public ModifiedParabolicCharacteristic(double exponent)
      Constructor with custom exponent.
      Parameters:
      exponent - the exponent for the parabolic curve (typically 1.5 to 2.5)

  • Method Details

    • getActualKv

      public double getActualKv(double Kv, double percentOpening)

      getActualKv.

      Calculates the actual Kv based on modified parabolic characteristic.

      Specified by:
      getActualKv in interface ValveCharacteristic
      Parameters:
      Kv - a double
      percentOpening - a double
      Returns:
      a double

    • getOpeningFactor

      public double getOpeningFactor(double percentOpening)

      getOpeningFactor.

      Returns the opening factor for modified parabolic characteristic using the formula: 

      factor = x ^ n

      where x is the fractional opening (0 to 1) and n is the exponent.

      Specified by:
      getOpeningFactor in interface ValveCharacteristic
      Parameters:
      percentOpening - a double
      Returns:
      a double

    • getExponent

      public double getExponent()
      Gets the exponent of the parabolic curve.
      Returns:
      the exponent value

    • setExponent

      public void setExponent(double exponent)
      Sets the exponent of the parabolic curve.
      Parameters:
      exponent - the exponent value (must be positive)