In this study, the temperature distribution in the piston of a Wärtsilä 20 engine was calculated using the finite element method. The FE-model was created using ABAQUS. Since the topic of this study was extensive, not all of the boundary conditions of the model were defined accurately. Thus, the phenomena around the studied piston in need of further study were defined by means of the FE-model and temperature measurements in the piston.

This study contains a literature search covering the theory of heat transfer, the basics of internal combustion engines and pistons; the literature search included publications that introduce a number of studies related to the present study. Following this, the creation of the FE-model and the definition of the boundary conditions are described. The calculation method and results are then presented, followed by a presentation of the measuring method, points and results. The results of the model and measurements are compared and the model is developed. Finally, the results of the developed model and measurements are compared and conclusions drawn.

The temperature measurements indicated that the tangential temperature variation in the piston head is intense. It also became clear that the temperature in the ring groove area is higher than was first calculated. By developing the model, the temperature variation in the piston head could be modeled to correspond to the measurement with certain exceptions. In the developed model, the temperature in the ring groove area remained partly significantly lower than measured. There were also substantial differences between the measured and calculated temperatures in the contact surfaces. These results mean that further studies of phenomena in the piston ring groove area, in the cooling chambers, near the fire land and the piston head surface should be undertaken in the future.