Modelling the effects of combustion and turbulence on near-wall temperature gradients in the cylinders of spark ignition engines

Abstract

• This is an article from the journal, Proceedings of the IMechE, Part D: Abstract: An existing 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 adjacent to the cylinder walls in both the unburned gas and in the discrete segments generated during the sequential burning process. A kÀå 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 is applied to the prediction of the flame propagation rate, excellent comparison is afforded between simulated and measured pressure±crank angle diagrams. Further validation is provided by comparison of near-wall temperature predictions with measured ones and the essential features of the observed boundary layer behaviour are reproduced.

Thermal analysis of an SI engine piston using different combustion boundary condition treatments

“…Since there is a small gap between piston crown and the liner, the captured gas temperature is the mean temperature of the crevice surfaces [6]. Therefore, the heat is conducted through the gas with the convective heat transfer coefficient, K gas .…”

“…In addition, their model was applied to realistic problems and gave a good agreement with available experimental data. Jenkin et al [6] modified an existing quasi-dimensional engine cycle model to enable accurate prediction of near wall temperature field in the burned and unburned gases. A k-e turbulence model had been incorporated into the engine cycle simulation.…”

Thermal and Structural Analysis of Functionally Graded NiCrAlY/YSZ/Al2O3 Coated Piston

“…Since there is a small gap between the piston crown and the liner, the captured gas temperature is the mean temperature of the crevice surfaces [32]. Therefore, the heat is conducted through the gas with the convective heat transfer coefficient, k gas .…”

Interring Gas Dynamic Analysis of Piston in a Diesel Engine considering the Thermal Effect

“…According to the structure of piston head and bore, shown in Figure 3, in order to get the gas temperatures in land volumes and groove volumes, it is important to know the temperature distribution of piston head and bore. In recent years, finite element method has been used to calculate piston temperature [21][22][23][24][25][26][27][28][29]. It should be noticed that after having identified one correlation for one engine, we acknowledge that those correlation parameters are not valid for another engine with similar characteristics.…”