A Methodology for Modeling the Cat-Heating Transient Phase in a Turbocharged Direct Injection Spark Ignition Engine



13th International Conference on Engines & Vehicles
Authors Abstract
This paper presents the modeling of the transient phase of catalyst heating on a high-performance turbocharged spark ignition engine with the aim to accurately predict the exhaust thermal energy available at the catalyst inlet and to provide a “virtual test rig” to assess different design and calibration options.
The entire transient phase, starting from the engine cranking until the catalyst warm-up is completed, was taken into account in the simulation, and the model was validated using a wide data-set of experimental tests.
The first step of the modeling activity was the combustion analysis during the transient phase: the burn rate was evaluated on the basis of experimental in-cylinder pressure data, considering both cycle-to-cycle and cylinder-to-cylinder variations.
Then, as far as the exhaust temperatures are concerned, a detailed model of the thermocouples was implemented to replicate the physical behavior of the sensors during the warm-up and to compare the simulated temperatures with the measured ones.
Finally, a complete analysis of the energy balance during the transient was carried out: the thermal power available to the catalyst inlet was obtained from a complete analysis of power losses (i.e. friction and pumping losses, in-cylinder heat transfer, engine block and engine coolant heating, exhaust manifold heat transfer, etc.).
In conclusion, the proposed methodology allows to reliably simulate in details the Cat-Heating transient, showing a valuable potential in driving the main design and calibration choices during the engine development process.
Meta TagsDetails
Millo, F., Rolando, L., Zanelli, A., Pulvirenti, F. et al., "A Methodology for Modeling the Cat-Heating Transient Phase in a Turbocharged Direct Injection Spark Ignition Engine," SAE Technical Paper 2017-24-0010, 2017, https://doi.org/10.4271/2017-24-0010.
Additional Details
Sep 4, 2017
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Technical Paper