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net.simplace.sim.components.vapourpressure.fao56.Vapourpressure

Calculates vapour pressure by one of (FAO 56) methods chosen by the user.

List of calculation methods and data needed

Method	Description	Required input data	Additional parameters	Remark
1	Dewpoint	dewpoint temperature	-	default calculation method
2	Psychrometric Data	dry and wet bulb temperature	altitude, psychrometric constant of instrument (default 0.00080)
3	Relative max and min humidity	max and min relative humidity, min and max temperature	-	-
4	Relative max humidity	max relative humidity, min temperature
5	Relative mean humidity	mean relative humidity, min and max temperature

For documentation of the formulas please check the orginal reference (FAO 56)

References

(FAO 56): Allen, Crop evapotranspiration - Guidelines for computing crop water requirements - FAO Irrigation and drainage paper 56, 1998

Component Variables

Content Type	Name	Description	Data Type	Unit	Min Value	Max Value	Default Value
constant	cAltitude	elevation above sea level	DOUBLE	m	-	-	0.0
constant	cCalculationMethod	calculation method	INT		-	-	1
constant	cPsychrometricConstantInstrument	psychrometric constant of instrument	DOUBLE	1	-	-	8.0E-4
input	iRelHumidityMax	maximum relative humidity	DOUBLE	%	-	-	0.0
input	iRelHumidityMean	mean relative humidity	DOUBLE	%	-	-	0.0
input	iRelHumidityMin	minimum relative humidity	DOUBLE	%	-	-	0.0
input	iTDewpoint	dew point temperature	DOUBLE	°C	-	-	0.0
input	iTDryBulb	dry bulb temperature	DOUBLE	°C	-	-	0.0
input	iTMax	maximum daily temperature	DOUBLE	°C	-	-	0.0
input	iTMin	minimum daily temperature	DOUBLE	°C	-	-	0.0
input	iTWetBulb	wet bulb temperature	DOUBLE	°C	-	-	0.0
out	ActualVapourPressure	actual vapour pressure	DOUBLE	kPa	-	-	0.0

public class Vapourpressure extends net.simplace.sim.model.FWSimComponent {
// Public Constructors
public Vapourpressure();

// Public Instance Methods

public HashMap createVariables(); // Defines
net.simplace.sim.model.FWSimComponent

Create the FWSimVariables as interface for this SimComponent

// Protected Instance Methods

protected void init(); // Defines net.simplace.sim.model.FWSimComponent

Initializes the fields by getting input and output FWSimVariables from VarMap

protected void process(); // Defines net.simplace.sim.model.FWSimComponent

Process the algorithm and write the results back to VarMap

protected FWSimComponent clone(FWSimVarMap aVarMap);
// Defines net.simplace.sim.model.FWSimComponent

creates a clone from this SimComponent for use in other threads

}

Hierarchy: java.lang.Object - net.simplace.sim.model.FWSimComponent (net.simplace.sim.util.FWSimFieldContainer) - Vapourpressure