Combustion dynamics at the top dead center position of a spark ignition engine

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A zero-dimensional spark ignition engine model was used to conduct a systematic study of combustion dynamics at the top dead center (TDC) position of a 5.734 liter, V8 spark-ignition engine. The model captures all the experimentally observed essential features concerning combustion at the TDC. The combustion dynamics at compression ratios, rc = 9.5, 10.5, 11.5 and 15.5 and fuel-air equivalence ratio, θ = 1.0 were investigated with the numerical model. The results show that for rc = 15.5, the fueloxidizer charge was consumed almost instantaneously. Furthermore, the data shows that it took about 153.0, 52.6, 21.0 and 1.43 ms at compression ratios, rc of 9.5, 10.5, 11.5 and 15.5 respectively for the in-cylinder combustion dynamics to reach a value T* = 1.0. In the last 0.01 ms, for all compression ratios, the rate of change of pressure, dp/dt lies in the range 108 < dp/dt < 1014 Pa/s while the corresponding temperature varies from 2230 ≤ T ≤ 2700 K. The study also shows that as the compression ratio increases both the adiabatic flame temperature and heat of combustion at the top dead center increases monotonically as well.