Internal Combustion Engine Heat Transfer and Wall Temperature Modeling: An Overview

Internal combustion engines are now extremely optimized, in such ways improving their performance is a costly task. Traditional engine improvement by experimental means is aided by engine thermodynamic models, reducing experimental and total project costs. For those models, accuracy is mandatory in order to offer good prediction of engine performance. Modelling of the heat transfer and wall temperature is an important task concerning the accuracy and the predictions of any engine thermodynamic model, although it is many times an overcome task. In order to perform good prediction of engine heat transfer and wall temperature, models are required for accomplish heat transfer from hot gases to engine parts, heat transfer inside each engine part, and also heat transfer to coolant and lubricating oil. This paper presents an overview about engine heat transfer and wall temperature modelling, with main purpose to aid engine thermodynamic modelling and offer more accurate predictions of engine performance, consumption and emission parameters. The most important correlation are reviewed for three engine heat transfer approaches: gas to wall, wall to wall and wall to liquid heat transfer models. In order to obtain good prediction of wall temperature, those three approaches must be coupled, which may imply convection-conduction-convection problems, although for some applications in diesel engines, radiation problems must be considered.