RADBC

Bulk Data Entry Defines the radiation boundary conditions and identifies CHBDYE entries for heat transfer analysis via radiation.

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
RADBC	`NODAMB`	`FAMB`	`CNTRLND`	`EID1`	`EID2`	`EID3`	`EID4`	`EID5`
	`EID6`	`EID7`	etc.

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
RADBC	23	0.9	334	12	34	33

Field	Contents	SI Unit Example
`NODAMB`	Ambient point for radiation exchange identification number. No default (Integer > 0)
`FAMB`	Radiation view factor between the face and ambient point. No default (Real ≥ 0)
`CNTRLND`	Control point for radiation boundary conditions. = 0 $q = σ \cdot FAMB \cdot (ε_{e} {(T_{e} + T_{a b s})}^{4} - α_{e} {(T_{a m b} + T_{a b s})}^{4})$ > 0 $q = σ \cdot FAMB \cdot u_{C N T R L N D} \cdot (ε_{e} {(T_{e} + T_{a b s})}^{4} - α_{e} {(T_{a m b} + T_{a b s})}^{4})$ Default = 0 (Integer ≥ 0)
`EIDi`	CHBDYE element identification number(s). Keywords `THRU` and `BY` are available for alternate format listing in ascending order of `EIDi`. No default (Integer > 0)

For a Heat Transfer Analysis via Radiation, PARAM,TABS can be used to define the absolute temperature scale, and PARAM,SIGMA is used to specify the Stefan-Boltzmann constant. Additionally, a RADBC entry can be used to define radiation boundary conditions. Both RADM and RADBC entries are referenced on the CHBDYE Bulk Data Entry.
NODAMB is treated as a black body with its own ambient temperature for radiation exchange between the surface element and space.