Charge Coupled Device camera recording and computational analysis of flame propagation in a spark-ignition engine

Homogeneous charge combustion in a four stroke cycle spark-ignition engine was studied using through-piston-photography with a gated-intensified CCD camera. Analysis of computer stored multiple exposed flame front images was carried out for various engine conditions, in conjunction with the test data and cylinder pressure signals. Representative turbulence scales were inferred from the flame propagation and cylinder pressure data. Fractal analysis of flame edge contours resulted in a fractal dimension D3 in the range 2.12 to 2.23 corroborating data presented elsewhere. A correlation is presented here between the standard deviation of peak cylinder pressure and the fractal dimension D3.