TY - JOUR
T1 - Induction times for thermal explosion and natural convection in porous media
AU - Viljoen, H. J.
AU - Gatica, J. E.
AU - Hlavacek, V.
N1 - Funding Information:
Acknowledgemenrs~Part of this work was supported by an NSF grant CPE83-I 0627. This support is gratefully acknowledged. The numerical computations were performed on a CRAY X-MI’ supercomputer at the National Center for Supercomputing Applications, University of Illinois at Urbana-Champaign. Hendrik J. Viljoen wants to acknowledge the financial support provided by the CSIR of the Republic of South Africa. Jorge E. Gatica gratefully acknowledges fellowship support from the Consejo National de Investigaciones Cientificas y Tecnicas of the Republic of Argentina.
PY - 1988
Y1 - 1988
N2 - Thermal explosion occurs when the heat generation of an exothermic reaction exceeds the system's capacity of heat removal. In fluid systems, natural convection acts as an additional heat transfer mechanism, and, for sufficiently large values of the Rayleigh number, the system can be stabilized. The evolution of this secondary flow is characterized by an induction period. Initially, the natural convection develops at a slow rate, but, after an induction time, it grows explosively. Equations are derived to determine the time to thermal explosion as well as the induction period for natural convection. Important parameters, such as the type and magnitude of the initial perturbation, and the aspect ratio of the cavity, are considered. Numerical results that support the validity of the equations are reported.
AB - Thermal explosion occurs when the heat generation of an exothermic reaction exceeds the system's capacity of heat removal. In fluid systems, natural convection acts as an additional heat transfer mechanism, and, for sufficiently large values of the Rayleigh number, the system can be stabilized. The evolution of this secondary flow is characterized by an induction period. Initially, the natural convection develops at a slow rate, but, after an induction time, it grows explosively. Equations are derived to determine the time to thermal explosion as well as the induction period for natural convection. Important parameters, such as the type and magnitude of the initial perturbation, and the aspect ratio of the cavity, are considered. Numerical results that support the validity of the equations are reported.
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U2 - 10.1016/0009-2509(88)80048-4
DO - 10.1016/0009-2509(88)80048-4
M3 - Article
AN - SCOPUS:38249032364
SN - 0009-2509
VL - 43
SP - 2951
EP - 2956
JO - Chemical Engineering Science
JF - Chemical Engineering Science
IS - 11
ER -