MODELING, DESIGN AND ANALYSIS OF AUTOMOTIVE ENGINE PISTON LUBRICATION AND DAMPING SYSTEM

Abstract

In internal combustion engines the piston reciprocates
due to the combustion forces. It reciprocates having a
clearance between cylinder liner and the piston skirt
and this clearance causes the piston to move laterally
as well. In this work a mathematical model have been
developed to find the response of reciprocating motion
as well as the lateral or secondary motion with total of
two degrees of freedom. For this purpose the
combustion force have been transformed using Fourier
transform method. The forces acting in both direction
such as primary direction and secondary direction
(lateral) have been plotted along with the response of
the piston under the influence of these forces. For this
purpose a 127 cc motorcycle piston have been
considered, while modeling the damping the viscous
properties of SAE 30 motor oil have been used, also
the motor oil lubrication is assumed hydrodynamic
and also as a Newtonian fluid. Similarly the stiffness
of the system have been derived using rotational work
energy principle. The equations have been solved and
plotted using Matlab.