SAE International Avenues for Predicting Piston Wear: Employing 2D and 3D Numerical Piston Dynamics Models 2008-01-1044

Efforts have been made in recent years to develop models that correctly capture the piston dynamics and accurately assess its performance. These models considered the reciprocating motion of the piston and its oscillatory motion in the plane perpendicular to the wrist-pin axis, assuming that piston travel in the plane parallel to the wrist-pin axis has negligible effects on dynamics and thus could be ignored. Also piston land interactions with the cylinder bore were often assumed negligible. In this work a new piston dynamics model that considers piston translation along the wrist-pin and second land interactions with the cylinder bore is employed to demonstrate that the motion in the third dimension becomes important when modeling the new generation pistons that feature uneven thrust sides. Piston dynamics and wear results are presented for different case studies and the wear patterns are examined.