On the stability of one-dimensional diffusion flames established between plane,parallel, porous walls

A one-dimensional, non-premixed flame stability analysis is undertaken.Oscillatory and cellular flame instabilities are identified by a careful studyof the numerically calculated eigenvalues of the linearized system of equations. The numerical investigation details the critical locations for changes in flame behaviour, as well as the critical values of variousparameters that affect flame stability. A critical Lewis number, greaterthan unity, is identified as the value where unstable oscillations maybegin to appear (Le?>?Le _c) and for which cellular flames can exist(Le?<?Le _c). Some prior discussions are clarified regarding theaforementioned critical values, as well as the role of convection inproducing flame instabilities. The methodology of the stability analysis isdiscussed in detail.