recordMaterial
Thermal properties of materials w/o storage
Extends from Modelica.Icons.Record (Icon for records).
Information
Base record for materials that declares the thermal properties.
The specific heat capacity can be zero, in which case the material will be modeled as a thermal resistor that does not store energy.
Note that the thermal resistance is in units of m2 K ⁄ W and not K ⁄ W because this record does not have the surface area as a parameter. The surface area will be defined in the model of the construction that uses this material. This allows use of the same material in walls, floors and ceilings of different surface area.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.Length | x | Material thickness | |
| Modelica.Units.SI.ThermalConductivity | k | Thermal conductivity | |
| Modelica.Units.SI.SpecificHeatCapacity | c | Specific heat capacity | |
| Modelica.Units.SI.Density | d | Mass density | |
| Real | R | Thermal resistance of a unit area of material | |
| Integer | nStaRef | 3 | Number of state variables in a reference material of 0.2 m concrete |
| Boolean | steadyState | (c < Modelica.Constants.eps or d < Modelica.Constants.eps) | Flag, if true, then material is computed using steady-state heat conduction |
| Boolean | ensureMonotonicity | false | Set to true to force derivatives dT/du to be monotone |
| Advanced | |||
| Integer | nSta | max(1, integer(ceil(nStaReal))) | Actual number of state variables in material |
| Real | piRef | 331.4 | Ratio x/sqrt(alpha) for reference material of 0.2 m concrete |
| Real | piMat | if steadyState then piRef else x*sqrt(c*d/k) | Ratio x/sqrt(alpha) |
| Real | nStaReal | nStaRef*piMat/piRef | Number of states as a real number |
| Properties for phase change material | |||
| Modelica.Units.SI.Temperature | TSol | Solidus temperature, used only for PCM. | |
| Modelica.Units.SI.Temperature | TLiq | Liquidus temperature, used only for PCM | |
| Modelica.Units.SI.SpecificInternalEnergy | LHea | Latent heat of phase change | |
| Boolean | phasechange | false | Flag, true if the material is a phase change material |
Revisions
-
December 10, 2022, by Michael Wetter:
Corrected annotation to avoid comparison for equality using real-valued parameter.
See also IBPSA, #1671. -
March 1, 2016, by Michael Wetter:
Removed test for equality ofRealvariables. This is for issue 493. -
May 21, 2015, by Michael Wetter:
Reformulated to reduce use of the division macro in Dymola. This is for issue 417. -
May 30, 2014, by Michael Wetter:
Removed undesirable annotationEvaluate=true. -
June 3 2010, by Michael Wetter:
Implemented adaptive computation of number of states based on a reference construction of 0.2 m concrete. -
March 6 2010, by Michael Wetter:
First implementation.