/RADIATION

Format

(1)	(2)	(3)	(5)	(7)	(9)
/RADIATION/`Radiative_Flux_ID`/`unit_ID`
`Radiative_Flux_title`
`surf_ID`_T	`fct_ID`_T	`sens_ID`
`Ascale`_x		`Fscale`_Y	`T`_start	`T`_stop	$ε$

Definitions

Field	Contents	SI Unit Example
`Radiative_Flux_ID`	Imposed radiative flux block identifier. (Integer, maximum 10 digits)
`unit_ID`	Unit Identifier. (Integer, maximum 10 digits)
`Radiative_Flux_title`	Imposed radiative flux block title. (Character, maximum 100 characters)
`surf_ID`_T	Identifier for surface which absorbs thermal radiation. (Integer)
`fct_ID`_T	Time function identifier for the temperature of heat source $T_{\infty}$ . (Integer)
`sens_ID`	Sensor identifier. (Integer)
`Ascale`_x	Abscissa (time) scale factor for `fct_ID`_T. Default = 1.0 (Real)	$[s]$
`Fscale`_Y	Ordinate (temperature) scale factor for `fct_ID`_T. Default = 1.0 (Real)	$[K]$
`T`_start	Start time. (Real)	$[s]$
`T`_stop	Stop time. (Real)	$[s]$
$ε$	Emissivity $0 < ε < 1$ . (Real)

Example (Thermal Loading)

#RADIOSS STARTER
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/UNIT/12
unit for imposed radiation load
Mg                  mm                   s
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/RADIATION/1/12
RADIATION from heat source
#  surf_ID    fct_ID   sens_ID
5      2003         0
#             ASCALE              FSCALE              TSTART               TSTOP                   E
0                   0                   0                   0                0.15
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/FUNCT/2003
temperature of heat source function of time
#                  X                   Y
0                 773
1                 700
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#ENDDATA

Comments

The radiation flux is calculated using:
(1)
$φ = ε σ (T^{4} - T_{\infty}^{4})$

Where,

T

Temperature of the surface (surf_ID_T) which absorbs thermal radiation

$σ$

The Stefan-Boltzmann constant

(2)
$σ = 5 {.669 x 10}^{-8} \frac{W}{m^{2} \cdot K^{4}}$

Since $σ$ is a constant which depends on the units, the unit system must be set correctly in /BEGIN and in the optional unit_ID which is used by the radiative flux block.
Thermal radiation is only compatible with the finite element formulation for heat transfer.
/RADIATION is not compatible with ALE applications (/ALE, /EULER). Thermal radiation will not be applied to ALE nodes or ALE elements.