Nodal modelling for advanced thermal-management of internal combustion engine

- Coolant and oil temperatures modelling for internal combustion engine.
- Nodal modelling of internal combustion engine in order to reduce warm up phase.
- The nodal modal can be used in order to reduce the engine mass.
- Experimental validation with an engine test bench but also with a vehicle test bench.

The evolution of temperatures in internal combustion engines during cold start is quite important. This greatly affects fuel consumption and vehicle emissions. In this paper, an advanced thermal management model is presented and used on an automotive Diesel engine in order to determine the evolution of the different temperatures during warm-up stage. The paper focuses on the complete description of the engine components, coolant circuit, and lubricant circuit. The objective is to calculate the heat exchanges between the thermal masses of sub-models (cylinder head, engine block, pistons, oil sump…) and the fluids. Experiments on an engine were realized in order to calibrate the model (heat release, friction losses…) but also to obtain the temperature evolutions during transient stage. These last results were used in order to validate the model. This approach gives the possibility to determine the coolant and oil temperature evolution with a minimum of nodes and a relatively short calculation time. The evolution of the coolant temperature in a vehicle during a NEDC cycle with a cold start was studied. A good agreement was obtained. Finally, the model was used in order to study the possibilities to reduce the vehicle mass by a reduction of the engine mass.