Comparison of Dynamical Models for Internal Combustion Engines

There has been an increasing interest of the automotive industry for making lighter and more efficient mechanical components. Based on that, fuel consumption, pollutant and cost reductions may be achieved.

In this work, three different methodologies for kinematical and dynamical analyses of the crank mechanism of internal combustion engines are developed. The first model is the traditional method and is widely used by the automotive industry due to its simplifying assumptions, which avoids the calculation of the connecting-rod inertia moment. The second uses the Newton-Euler equations for a system of multiple rigid bodies, considering the piston as a material point, while the connecting-rod and crank are treated as rigid bodies. The third model employs the software RecurDyn, which uses the recursive dynamic concept.

We compare the models based on results of their kinematical and dynamical behavior, defining their similarities and differences.