modelCWveg

Evaporation of the vegetation

Extends from BondLib.Interfaces.TwoPort (Partial model invoking two bondgraphic connectors).

Information

This model computes the evaporation of the vegetation. It uses the generic evaporation model together with an internal modulation computing the conductance of evaporation.


Parameters:

  ag:      Ground area of Biosphere (default value = 2368.9 m2)

  hai:     Convection coefficient equation intercept (default value = 39.6 kJ/(h.m2.K))

  avix:    Portion of Biosphere covered by vegetation (default value = 0.4)

  laix:    Leaf area index (default value = 2)

  lambda:  Latent heat of vaporization (default value = 2501 kJ/kg_water)

  rg:      Specific ground resistance of evaporation to vapor diffusion (default value = 0.0278 h.m2/kg_air)

  b1:      Stomatal resistance coefficient (default value = 20.3 kJ/kg_air)

  b2:      Specific canopy light reflection (default value = 61.2 kJ/(h.m2))

  taux:    Light adjustment factor (default value = 1)

  taup:    Canopy light extinction coefficient (default value = 0.6)

  pao:     Atmospheric pressure (default value = 87.848 kPa)


References:

  1. American Society of Heating, Refrigerating and Air-Conditioning Engineers (1997), ASHRAE Handbook of Fundamentals.
  2. Air Psychrometrics
  3. Kimball, B.A. (1986), A Modular Energy Balance Program Including Subroutines for Greenhouses and Other Latent Heat Devices, United States Department of Agriculture, ARS-33.

Parameters

TypeNameDefaultDescription
Modelica.SIunits.Areaag2368.9Ground area of Biosphere
Realhai39.6Convection coefficient equation intercept
Realavix0.4Percetage of Biosphere covered by vegetation
Reallaix2Leaf area index
Reallambda2501.0Latent heat of vaporization
Realrg0.0278Specific ground resistance of evaporation to vapor diffusion
Realb120.3Stomatal resistance coefficient
Realb261.2Specific canopy light reflection
Realtaux1Light adjustment factor
Realtaup0.6Canopy light extinction coefficient
Realpao87.848Atmospheric pressure

Connectors

TypeNameDefaultDescription
BondLib.Interfaces.BondConBondCon1 (from TwoPort)Left bond graph connector
BondLib.Interfaces.BondConBondCon2 (from TwoPort)Right bond graph connector

Components

TypeNameDefaultDescription
Reale1 (from TwoPort)Bondgraphic primary effort
Realf1 (from TwoPort)Bondgraphic primary flow
Reale2 (from TwoPort)Bondgraphic secondary effort
Realf2 (from TwoPort)Bondgraphic secondary flow
RealcaSpecific heat capacity of moist air
RealsoSpecific solar input to canopy
RealR0Specific boundary layer resistance of vegetation due to evaporation
RealR1Specific stomatal resistance of evaporation of vegetation
RealG0Specific boundary layer conductance due to evaporation
RealGBoundary layer conductance of evaporation
RealG2Bondgraphic conductance
mGSevmGSev1
SolarInputSolarInput1
Modelica.Blocks.Sources.ClockClock1