LOAD_THERMAL_RADIATION

Loads

*LOAD_THERMAL_RADIATION
"Optional title"
coid
entype, enid, $T_{amb}$, $d_{max}$, $\Delta t_{update}$

Parameter definition

Variable
Description
coid
Command ID
entype
Entity type
options: FS, G, GS, P, PS, ALL
enid
Entity identification number
$T_{amb}$
Ambient temperature
$d_{max}$
Interaction cut-off distance
default: not used
$\Delta t_{update}$
Interaction list update interval
default: no update

Description

This command is used to define the thermal radiation interaction between surfaces. The radiating power $q$ per unit area from a surface is defined as:

$\displaystyle{q = \varepsilon \sigma T^4}$

where $\varepsilon$ is the emissivity (defined in PROP_THERMAL), $\sigma$ is the Stefan-Boltzmann constant and $T$ is the absolute temperature. Radiating energy can be absorbed by (and partially reflected from) surrounding surfaces that are in line-of-sight. The emissivity of a receiving surface controls the energy that is absorbed. Reflected energy can be transferred to surrounding faces that are in line-of-sight.

The ambient temperature $T_{amb}$ constitutes an external (background) heat source.

Example

Thermal radiation

Thermal radiation and interaction between a hot and a cold plate. The emissivity of the cold plate is low and a significant amount of energy is reflected back to the hot plate. Hence, the back face of the hot plate cools off quicker than the front face.

*UNIT_SYSTEM SI *TIME 100.0, 0, 0, 1.0e-3 # # --- SENSOR --- # *OUTPUT_SENSOR "Sensor 1" 1, 1, -0.03, "Sensor 2" 2, 1, -0.01 # # --- MESH --- # *COMPONENT_BOX "Hot" 1, 1, 2, 6, 6 -0.03, -0.1, -0.1, -0.01, 0.1, 0.1 *COMPONENT_BOX "Cold" 2, 2, 2, 6, 6 0.01, -0.1, -0.1, 0.03, 0.1, 0.1 # # --- MATERIAL --- # *MAT_RIGID 1, 3000.0, 0, 0, 0, 1 *PROP_THERMAL 1, 0, 400.0, 1.0, 0, 0, 1.0 *MAT_RIGID 2, 3000.0, 0, 0, 0, 2 *PROP_THERMAL 2, 0, 400.0, 1.0, 0, 0, 0.1 # # --- PART --- # *PART "Hot" 1, 1 "Cold" 2, 2 # # --- INITIAL CONDITION --- # *INITIAL_TEMPERATURE P, 1, 0, 1273.15 *INITIAL_TEMPERATURE P, 2, 0, 273.15 # # --- RADIATION --- # *LOAD_THERMAL_RADIATION "Test" 1 ALL, 0, 273.15 *END
Interaction between a hot and a cold plate