Abstract:
Presence of fully established EHL film effectively prevents adhesive wear
and reduces friction between piston assembly and cylinder liner under engine
normal operating conditions. Absence of the same during initial start up, does
affects the lubrication mechanism and may cause significant reduction in engine
predicted design life. A comprehensive mathematical model representing EHL
phenomenon may lead towards a viable solution of above stated problem. Earlier
studies modeled EHL phenomenon but under ideal conditions.
This research aims to mathematical model transient piston skirt EHL
phenomenon by using 2-D Reynolds equation ( for pressure profiles generation on
piston skirt) and 2-D Transient Thermal Energy equation ( for temperature
distributions within oil film) during initial engine start up conditions with
particular emphasis on shear heating and temperature rise of lubricant film
between piston and liner, its effects on the viscosity of lubricant and oil film
thickness which, in turn, affects load carrying capacity of the lubricant. This
research will analyze temperature dependent viscosity, its variation and effects on
EHL. This research will also undertake parametric studies on the subject after duly
incorporating pressure-temperature- viscosity relationship in the developed model.
