'Spark ignition engines' effects of combustion and turbulence on near wall temperature gradients in the cylinders.

摘要

Quasi dimensional engine cycle model has been modified to enable accurate prediction of the near-wall temperature field in the burned and unburned gases. This has been achieved by dividing the cylinder into a number of discrete masses, each of which has a unique state. These discrete masses are assumed to remain stacked in layers adijacent to the cylinder walls in both the unburned gas and in the discrete segments generated during the sequential burning process. A Kinetic energy and dissipation rate turbulence model has been incorporated into the engine cycle simulation, providing information on the nature of the instantaneous in-cylinder turbulence for input to a fractal flame model to depict the flame propagation process. When this approach in applied to the prediction of the flame model to depict the flame propagation process. When this approach is applied to the prediction of the flame propagation rate, excellent comparison is afforded between simulated and measured pressure-crank angle diagrams.