modelmGSev
Extends from BondLib.Interfaces.ModTwoPort (Partial model invoking two bondgraphic connectors and one signal connector).
Information
Evaporation is modeled in this program using Teten's law [1,2], an experimental equation that avoids the need of using steam tables.In the process of evaporation, sensible heat gets converted to latent heat.
Water vapor is at a higher energy level than liquid water. In order to evaporate, the activation energy must be overcome that is needed to provide the water molecules with the additional energy. This energy is taken out of the thermal domain.
In our model, humidity is used as an effort variable. It gets multiplied with a quantity that corresponds to the power converted in the process.
The humidity generated in the process of evaporation is proportional to the difference between the current humidity and the humidity at saturation vapor pressure, i.e., the humidity at the dew point.
Parameters: pao: Atmospheric pressure (default value = 87.848 kPa)
References:
- Murray, F.W. (1967), "On the Computation of Saturation Vapor Pressure," L. Appl. Meteorol., 6, pp. 203-204.
- Otárola A., M. Holdaway, L.-Å. Nyman, S.J.E. Radford, and B.J. Butler (2005), "ALMA Memo #512 - Atmospheric Transparency at Chajnantor: 1973-2003," Atacama Large Millimeter Array Memos.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Real | pao | 87.848 | Atmospheric pressure |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| BondLib.Interfaces.BondCon | BondCon1 (from ModTwoPort) | Left bond graph connector | |
| BondLib.Interfaces.BondCon | BondCon2 (from ModTwoPort) | Right bond graph connector | |
| Modelica.Blocks.Interfaces.RealInput | s (from ModTwoPort) | Signal input |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Real | e1 (from ModTwoPort) | Bondgraphic primary effort | |
| Real | f1 (from ModTwoPort) | Bondgraphic primary flow | |
| Real | e2 (from ModTwoPort) | Bondgraphic secondary effort | |
| Real | f2 (from ModTwoPort) | Bondgraphic secondary flow | |
| Real | G | Bondgraphic evaporation conductance | |
| Real | svp | Saturation vapor pressure | |
| Real | hum | Humidity ratio | |
| Real | P | Power flow into evaporation |