Approximations for burning velocities and Markstein numbers for lean hydrocarbon and methanol flames

Burning velocities of lean-to-stoichiometric n-heptane-, iso-octane-, and methanol-air mixtures have been numerically calculated over a wide range of pressure and preheat temperatures. The numerical calculations are based on elementary reaction mechanisms comprising a few hundred reactions. They are then approximated using a two-equation analytic expression that has successfully been applied for flames of methane, ethylene, ethane, acetylene, and propane. Markstein numbers are also predicted for all these fuels. The predictions are compared with the few experimental data on Markstein numbers that exist in the literature. Copyright (C) 1997 by The Combustion Institute