Abstract
The objective of this contribution is to improve the rate of heat release for quasi-dimensional combustion models based on both a physical relationship for the turbulent flame velocity and an empirical correlation. The latter constitutes a relationship between depleted fuel, equivalence ratio and residual gas, whereas the physical model takes into account the interaction between turbulence and flame speed. This improves the rate of heat release, in particular at an advanced stage of combustion, when the flame front interacts with the surfaces of piston, cylinder head and liner. Under these conditions the basic concept of quasi-dimensional modeling causes unreasonable employed agree well with measured engine data, whereby the physical approach is believed to be more general.