Passive control of piston secondary motion using nonlinear energy absorbers

The impulsive behaviour of the piston in the cylinder liner plays a key role in the Noise, Vibration and Harshness (NVH) of internal combustion engines. There have been several studies on the identification and quantification of piston impact action under various operation conditions. In the current study, the dynamics of the piston secondary motion are initially explored in order to describe the aggressive oscillations, energy loss and noise generation. The control of piston secondary motion (and thus, impacts) is investigated using a new passive approach based on energy transfer of the highly transient oscillations to a nonlinear absorber. The effectiveness of this new method for improving the piston impact behaviour is discussed using a preliminary parametric study that leads to the conceptual design of a nonlinear energy absorber.