<div>An analytical method for nonlinear three-dimensional (3D) multi-body flexible
dynamic time-domain analysis for a single-cylinder internal combustion (IC)
engine consisting of piston, connecting rod, crank pin, and liner is developed.
This piston is modeled as a 3D piston that collides with the liner as in a real
engine. The goal is to investigate the piston slap force and subsequent liner
vibration. Liner vibrational velocity is directly responsible for pressure
fluctuations in the coolant region resulting in bubble formation and subsequent
collapse. If the bubble collapse is closer to the liner surface, cavitation
erosion in the liner might occur. The mechanism of liner cavitation is briefly
explained, which would take a full computational fluid dynamics (CFD) model to
develop, which is out of scope for the present work. However, as a first step,
the present method focused on a comprehensive and accurate estimation of the
highest inward and outward liner velocities, which are directly related to the
bubble formation and collapse, respectively. Sensitivity of liner velocity to
different engine-operating conditions (warm and hot, with highest skirt
temperatures of 178 and 130°C), piston pin bore offsets (thrust side,
anti-thrust side directions in the amounts of 0.6 mm, and the nominal no offset
case), and liner thicknesses are determined. Piston thermal growth is considered
as part of the analysis resulting in interference condition between piston skirt
and liner under the hot operating condition and low minimum clearance under the
warm condition. Correlation of liner velocity contour plots with real engine
liner cavitation erosion is presented. Analytical model showed a maximum liner
inward velocity of 55 mm/s with no piston pin offset under nominal
engine-operating configuration. A correlation has been found between location of
this highest liner velocity and location of the actual cavitation erosion in the
field.</div>