Salbrechter, S., Krenn, M., Pirker, G., Wimmer, A. et al., "Engine Operating Parameter-based Heat Transfer Simulation to Predict Engine Warm-up," SAE Technical Paper 2014-01-1103, 2014, doi:10.4271/2014-01-1103.
Optimization of engine warm-up behavior has traditionally made use of experimental investigations. However, thermal engine models are a more cost-effective alternative and allow evaluation of the fuel saving potential of thermal management measures in different driving cycles. To simulate the thermal behavior of engines in general and engine warm-up in particular, knowledge of heat distribution throughout all engine components is essential. To this end, gas-side heat transfer inside the combustion chamber and in the exhaust port must be modeled as accurately as possible.Up to now, map-based models have been used to simulate heat transfer and fuel consumption; these two values are calculated as a function of engine speed and load. To extend the scope of these models, it is increasingly desirable to calculate gas-side heat transfer and fuel consumption as a function of engine operating parameters in order to evaluate different ECU databases.This paper describes the creation of a parameter-based heat transfer model using a statistical approach. The data for this model is obtained from combustion process calculation using rate of heat release (ROHR) simulation. The procedure is described in detail using the example of a DI gasoline engine. In addition, the basic structure of a thermal engine model is defined.