Special Session 62: 

Gelfand type problems for reactive jets: autoignition of turbulent jets

Peter Gordon
Kent State University
USA
Co-Author(s):    Uday G. Hegde and Michael C. Hicks
Abstract:
Gelfand problem is one of the canonical problems in the theory of non-linear parabolic and elliptic PDEs . This problem naturally arises in the Frank-Kamenetskii theory of thermal explosion (autoignition) and describes an initial stage of evolution of a temperature field in reactive materials and mixtures. In this talk I will present a generalization of Gelfand problem for the analysis of autoignition of reactive turbulent jets. I will present both the derivation of this new model and its analysis. The latter is performed using a combination of rigorous, formal asymptotic and numerical techniques. It will be shown that similar to the classical Gelfand problem an autoignition in jets occur exclusively owing to the absence of self-similar temperature distribution which, in mathematical terms, leads to loss of regularity (blow-up) of underlying PDE. The detailed analysis of self-similar temperature profiles will be presented and a sharp characterization of an autoignition event in terms of principal geometric and physical parameters of the problem will be given. This a joint work with U.G. Hegde and M.C. Hicks of NASA Glenn Research Center.