Design of flexible reduced kinetic mechanisms

Reduced mechanisms are often used in place of detailed chemistry because th e computational burden of including all the species continuity equations in the reactor model is unreasonably high. Contemporary reduction techniques produce mechanisms that depend strongly on the nominal set of problem param eters for which the reduction is carried out. Effects of variability in the se parameters on the reduced mechanism are the focus of this work. The rang e of validity of a reduced mechanism is determined for variations in initia l conditions. Both sampling approaches and quantitative measures Of feasibi lity, such as the flexibility index and the convex hull formulation, are em ployed. The inverse problem of designing a reduced mechanism that covers th e desired range of initial conditions is addressed using a multiperiod appr oach. The effect of the value of a user-defined tolerance parameter, which determines whether the predictions made by the reduced mechanism are accept able, is also assessed. The analytical techniques are illustrated with exam ples from the literature.