/RADIATION

Block Format Keyword Describes the imposed radiation flux to environment.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
/RADIATION/Radiative_Flux_ID/unit_ID
Radiative_Flux_title
surf_IDT fct_IDT sens_ID              
Ascalex FscaleY Tstart Tstop ε

Definition

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_IDT Identifier for surface which absorbs thermal radiation.

(Integer)

 
fct_IDT Time function identifier for the temperature of heat source T .

(Integer)

 
sens_ID Sensor identifier.

(Integer)

 
Ascalex Abscissa (time) scale factor for fct_IDT.

Default = 1.0 (Real)

[ s ]
FscaleY Ordinate (temperature) scale factor for fct_IDT.

Default = 1.0 (Real)

[ K ]
Tstart Start time.

(Real)

[ s ]
Tstop 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

  1. The radiation flux is calculated using:
    (1)
    φ = ε σ ( T 4 T 4 )
    Where,
    T
    Temperature of the surface (surf_IDT) which absorbs thermal radiation
    σ
    The Stefan-Boltzmann constant
    (2)
    σ = 5 .669 x 10 -8   W m 2 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.

  2. Thermal radiation is only compatible with the finite element formulation for heat transfer.
  3. /RADIATION is not compatible with ALE applications (/ALE, /EULER). Thermal radiation will not be applied to ALE nodes or ALE elements.