This paper is concerned with the Residual Gas Fraction measurement and estimation on a Homogeneous Charge Compression Ignition (HCCI) engine. A novel incylinder gas sampling technique was employed to obtain cyclic dynamic measurements of CO 2 concentration in the compression stroke and in combination with CO 2 concentration measurements in the exhaust stroke, cyclic Residual Gas Fraction was measured. The measurements were compared to estimations from a physical, 4-cylinder, single-zone model of the HCCI cycle and good agreement was found in steady engine running conditions. Some form of oscillating behaviour that HCCI exhibits because of exhaust gas coupling was studied and the model was modified to simulate this behaviour.
This paper is concerned with the development of a simple physical model of a gasoline engine cycle where the energy release is via Controlled Auto-Ignition. It uses simple thermodynamic concepts, and well-established gas exchange and heat transfer sub-models to predict the pressures and temperatures in the engine cycle. The combustion event itself is modelled in a semi-empirical fashion. The model is an important extension of existing single-zone models and it persists between multiple cycles, enabling the capture of the cycle-to-cycle exhaust gas coupling. The model was compared with data obtained at steady engine running conditions, and good agreement was found. Controlled Auto-Ignition was attained by diluting the mixture with exhaust gas trapped in the cylinder, as a result of an early Exhaust Valve Closing.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.