Technical Paper
Further Aspects of Combustion Modelling in Spark Ignition Engines
1990-02-01
900684
An existing “phenomenological” computer model of the spark ignition engine combustion process has been used to reveal further information on flame development in such engines. A detailed flame map and pressure-time diagram ( from Ref ( 6 ) ) has been analysed to determine more precisely the 3-dimensional nature of the flame development across the CFR engine cylindrical disc combustion chamber. The conventional spherical flame assumption (centred at the spark plug) is found to be inaccurate with the extent of the deviation from sphericity varying with flame radius and compression ratio in both the vertical and horizontal (plan view) planes. The flame map provides input data in the form of enflamed volumes, heat transfer surface areas etc for the subsequent evaluation of turbulent burning velocities, mass burn rates, pressure-time diagrams etc.