CHEMISTRY AND DIAGNOSTICS OF FUEL RICH COMBUSTION

The chemistry of fuel-rich combustion is more complex than combustionin lean and stoichiometric conditions and by consequencael so its diagnostics is peculiar. he essential feature of rich combustion is that a portion of the carbon atoms contained i nto the fuel is transformed into complex structures with high molecular mass.They include polycyclic aromatic hydrocarbons (PAH), tar, soot particles and polyhedral carbon structures, like C60 nd C70.The paper summarizes the main experimental results obtained in rich premixed flat flames with different fuels, C/O ratios,temperatures and pressure underlining the different optical and chemical diagnostics employed. Subsequently the effort to model the different phases of the kinetics of rich combustion are shortly reviewed.The finala part deals with recent experimental results on the inception stage of soot formation at atmospheric pressure and discusses new directions for more comprehensive models of the chemistry of rich combustion.