抄録 A refined two-zone heat release model for combustion diagnostics in spark-ignition (SI)
engines was developed and assessed. The novelty of the model includes the following
improvements. A more general complex-variable formulation of Newton's convection law
was applied for modeling the instantaneous surface-averaged heat flux so as to take the
unsteadiness of gas-wall temperature difference into account. A CAD procedure was
introduced to estimate the heat-transfer wall areas of the burned-and unburned-zone for …

The present work gives a further contribution to the heat release analysis of the measured
cylinder pressure timehistory, that is the most commonly used combustion diagnostic for
determining the actual burning rate in spark-ignition engines. A critical examination was
made of the thermodynamic models applied for such an analysis, paying specific attention to
their calibration techniques, to the simplifications adopted and to the correlations used for
evaluating the bulk gas-wall heat transfer. With respect to these latter, the convective surface …