Abstract

N u m e ric a l a n d E x p e r im e n ta l S tu d y o f R e a c tio n F r o n t P r o p a g a tio n in C o n d e n s e d P h a s e S y s te m s Certain noncatalytic exothermic chemical reactions of the type solid-solid characterized by high values of activation energy and heat of reaction represent an example of strongly nonlinear chemi cally reacting systems. In these systems different types of propagating waves can be observed such as constant pattern, planar pulsating, and rotating waves. Numerical simulations in two and three spatial dimensions predict, qualitatively, the same behavior as experimentally observed. For geome trically large systems multihead spinning or erratic waves occur, which bifurcate from a planar pulsating front. In nonadiabatic systems the spinning wave is more resistant to extinction than the one-dimensional planar pulsating front. List of Symbols Subscripts C E Ko R R' concentration, kg m~3 heat capacity, Jkg-1 K_1 diameter, m activation energy, J mol-1 rate constant heat transfer coefficient, Jm "2s"' K universal gas constant, J mol"1 K-1 radius of sample, m radial coordinate, m reaction rate, mol m-3s-1 rate t time, s >C.)Rg T«?exp(E/Ä r* = Ek0(-AH)CSO temperature, K reference time, s u = z yJq CP\X f* dimensionless axial coordinate z axial coordinate, m. Greek Symbols öl = 4 KH/d dimensionless heat transfer coefficient ß = Rg TJE dimensionless activation energy _ —p—g * dimensionless heat of reaction C0 E(— AH) AH heat of reaction, Jkg 1 > 7 = 1— Cs/Cso conversion E ft = ----^{T— T*) dimensionless temperature R T ' heat conductivity, J m 1 s 1 K 1 v = At^/g Cpn2 d2 dimensionless circumference £ = r/R dimensionless radial coordinate g density, kg m"3 t dimensionless time (j) angular coordinate < Z > = <j>j2 n dimensionless angular coordinate Reprint requests to Prof. V. Hlavacek,