Radiation Boundary Material Property
Description: Defines the radiation property of a boundary element for heat transfer analysis.
Format:
Example:
| Field | Definition | Type | Default |
|---|---|---|---|
| RADMID | Material identification number. | Integer > 0 | Required |
| ABSORP | Surface absorptivity. | 0.0 ≤ Real ≤ 1.0 | See Remark 2. |
| EMISIV | Surface emissivity. | 0.0 ≤ Real ≤ 1.0 | See Remark 2. |
Remarks:
- ABSORP will default to EMISIV when EMISIV field is specified and ABSORP field is blank. EMISIV will default to ABSORP when ABSORP field is specified and EMISIV field is blank. If both fields are blank, ABSORP and EMISIV will be set to 1.0.
- For cavity radiation, if ABSORP is zero, it will be set to EMISIV.
- The RADM entry is directly referenced only by a CHBDYG or CHBDYP surface element entry.
- Two PARAM entries are required for radiation heat transfer:
- TABS defines the absolute temperature scale factor used to convert temperature to absolute. (See Section 5, Parameters, for more information on TABS.)
- SIGMA (
) is the Stefan-Boltzmann constant. (See Section 5,
Parameters, for more information on
SIGMA.)
- The TABLEMj enforces the element temperature as the independent variable. Blank or zero fields means there is no temperature dependence of the referenced property on the RADM entry.