Thermal Systems Modeling and Control of Flex-Fuel Combustion Engines for Real-Time Applications

Abstract

The modeling of the engine as a thermal system, in addition to enhancing the understanding of local and global energy flows, can be used in conjunction with thermodynamic control to reduce fuel consumption and emissions. This article presents some considerations on thermal system modeling in order to use the model in a flex-fuel gasoline-ethanol engine without compromising real-time response. To avoid calculating the power loss to the cylinder wall complex and computationally expensive, a different methodology was employed. Due to the enthalpy-based approach used, it was necessary to model both the gas temperature in the intake manifold and the exhaust manifold, aiming for simplicity once again to maintain real-time response unaffected.