Exhaust emissions regulations are forcing the development of innovative and complex engine layouts. For Spark Ignition (SI) engines, possible ways to reduce fuel consumption and emission pollutants are: direct injection, displacement downsizing, multi-stage turbocharging, supercharging, turbulence control in admission using devices like swirl or tumble control valves (SCV and TCV), variable valve timing and/or actuation (for example VVT, Fiat Multiair, …) and exhaust gas recirculation systems. Engine complexity leads to increasing effort required for optimal engine control calibration. The methodology proposed is based on virtual simulation of the whole engine system. It aims to provide a deeper understanding of physical phenomena using advanced computing technologies, which have been accessible only in the last years. The object is a one-dimensional model, fast enough to be used in an iterative loop, with the aim of optimizing the pre-calibration of the main functions of the engine control systems, thus reducing the need of experimental tests and consequently saving time and costs. After building the full predictive engine model, the first step is the model reduction to make the model faster and to reduce the computational effort, without losing reliability in simulation results. Second step is the definition of the calibration scheme. The scheme has to be closely related to the virtual tool accuracy. This project wants to demonstrate the possibility of using simulation tool in combination of 1D simulation with real-time model-based control. Model realization and subsequent reduction procedure has been studied to limit accuracy loss, especially for the variables being used for virtual calibration. Potentialities and limits of the 1D model simulation are presented in this work, together with engine working constraints, like emissions limitation, fuel consumption reduction, components protection, etc.. This paper shows the overall virtual-engine base calibration methodology applied on a Gasoline Direct Injection (GDI) turbocharged and supercharged engine, equipped with Tumble Control Valves (TCV) and a Variable Valve Timing (VVT) system. Simulation (and corresponding look-up-tables calibration) results are presented in the last part oft he paper, demonstrating the potential of adopting the proposed methodology as an intermediate step between engine development and calibration-related test cell (and on-board) activities.
Virtual Engine as a Tool for Model-Based Calibration: GDI Engine Case Study
CAVINA, NICOLO'
2012
Abstract
Exhaust emissions regulations are forcing the development of innovative and complex engine layouts. For Spark Ignition (SI) engines, possible ways to reduce fuel consumption and emission pollutants are: direct injection, displacement downsizing, multi-stage turbocharging, supercharging, turbulence control in admission using devices like swirl or tumble control valves (SCV and TCV), variable valve timing and/or actuation (for example VVT, Fiat Multiair, …) and exhaust gas recirculation systems. Engine complexity leads to increasing effort required for optimal engine control calibration. The methodology proposed is based on virtual simulation of the whole engine system. It aims to provide a deeper understanding of physical phenomena using advanced computing technologies, which have been accessible only in the last years. The object is a one-dimensional model, fast enough to be used in an iterative loop, with the aim of optimizing the pre-calibration of the main functions of the engine control systems, thus reducing the need of experimental tests and consequently saving time and costs. After building the full predictive engine model, the first step is the model reduction to make the model faster and to reduce the computational effort, without losing reliability in simulation results. Second step is the definition of the calibration scheme. The scheme has to be closely related to the virtual tool accuracy. This project wants to demonstrate the possibility of using simulation tool in combination of 1D simulation with real-time model-based control. Model realization and subsequent reduction procedure has been studied to limit accuracy loss, especially for the variables being used for virtual calibration. Potentialities and limits of the 1D model simulation are presented in this work, together with engine working constraints, like emissions limitation, fuel consumption reduction, components protection, etc.. This paper shows the overall virtual-engine base calibration methodology applied on a Gasoline Direct Injection (GDI) turbocharged and supercharged engine, equipped with Tumble Control Valves (TCV) and a Variable Valve Timing (VVT) system. Simulation (and corresponding look-up-tables calibration) results are presented in the last part oft he paper, demonstrating the potential of adopting the proposed methodology as an intermediate step between engine development and calibration-related test cell (and on-board) activities.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
