Combined heat conduction and heat radiation in one-dimensional solid

• Published in: AIChE journal Vol. 52; no. 2; pp. 478 - 483
• Main Authors: Maruyama, Toshiro, Satake, Hiroaki
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.02.2006; Wiley Subscription Services; American Institute of Chemical Engineers
• Subjects: Applied sciences; blackbody; Chemical engineering; energy equation; Exact sciences and technology; Heat and mass transfer. Packings, plates; Heat conductivity; Heat transfer; optical thickness; Radiation; Solids; Temperature; Temperature distribution; Heat radiation; Heating; Heating rate; radiation; energy equation; Optical thickness; Heat transfer; blackbody
• ISSN: 0001-1541; 1547-5905
• DOI: 10.1002/aic.10671

The transient changes in the temperature of a solid material heated by radiation were obtained by numerical calculations using an unsteady one‐dimensional (1‐D) energy equation. The radiative loss of heat from the surface of a heated solid increases with an increase in the radiation flux. Therefore, the net blackbody radiation into a semi‐infinite solid keeps a higher proportion of the initial flux at a lower dimensionless initial flux I0(0)/αk(Tb − T0). In the case of bidirectional radiation to a finite solid, the relatively homogeneous heating can be accomplished at the optical thickness αL ≅ 100. The heating rate is very low at αL ≲ 10−1 resulting from the absorption of a small part of the radiation energy. On the other hand, the heating rate is high at αL ≳ 101, but the heating is limited to a region near the wall, which results in an inhomogeneous temperature profile. At αL ≳ 102, the temperature profiles become identical with that obtained for αL → ∞. © 2005 American Institute of Chemical Engineers AIChE J, 2006