Kinetic modelling of a surrogate diesel fuel applied to 3D auto-ignition in HCCI engines

ing a methyl side hydrogen atom; the ipso-additions (addition of an atom to an aromatic ring leading to the abstraction of another atom or of a radical) of H-atoms producing naphthalene and methyl radicals; the ipso-additions of O-atoms forming methylnaphtoxy radicals and H-atoms; the additions of OH radicals leading to methylnaphthols and H-atoms; the metatheses by H-abstraction. As in the case of toluene, the abstractions of hydrogen atoms were considered from the methyl side, but also from the rings. Pitsch (1996) did not consider the additions of atoms or radicals, neither the abstractions of H-atoms from the rings. The related rate constants are derived from those proposed for toluene (Bounaceur et al., 2005). The reactions of resonance stabilized phenylbenzyl radicals are close to those of toluene: the decomposition by formation of a C5 ring (here, by formation of indenyl radicals and acetylene), the reactions with oxygen molecules to give naphthaldehyde and the combinations with H and O-atoms, OH, HO2 and methyl and phenylbenzyl radicals are taken into account. Products obtained by combination are methyl naphthalene, naphthaldehyde, methylhydroxy naphthalene, methylhydroperoxy naphthalene, which immediately decomposes by breaking of the O-OH bond, ethylnaphthalene and bi-1-methylnaphtyl, respectively. Two differences were nevertheless made in order to obtain satisfactory simulations: the formation of peroxy radicals was not considered and the recombination with HO2 radicals led to the direct formation of naphthaldehyde or naphtyl radicals with the rate constants proposed by Emdee et al. (1992) for a similar reaction in the case of toluene. Naphthyl radicals and the radicals obtained by H-abstractions from the rings react similarly to phenyl radicals, i.e. mainly by reactions with oxygen molecules to give naphthoxy or methylnaphthoxy radicals and by combinations with H and O-atoms, OH, HO2 and methyl radicals. In the case of naphthyl radicals, we have also considered the addition to acetylene to form acenaphthalene as proposed by Pitsch (1996). The reactions of naphthoxy and methylnaphthoxy radicals are directly derived from those of cresoxy radicals, i.e. CO eliminations with rearrangement and terminations with H-atoms. The