Multiphysics analysis for the determination of valvetrain characteristics

The ideal function of a valvetrain system is to synchronize the opening and closing of the inlet and exhaust valves with the required thermodynamics of the combustion process. As such, ideally a kinematic-type mechanism is desired. However, the timing requirements in the action of each valve and between any inlet-exhaust pair necessitate the use of contacting pairs of suitable profiles. The very existence of contact renders the problem one of complex non-linear dynamics, which is further exacerbated by the translational imbalance of the reciprocating compliant elements such as the valve itself. The interplay between these various forms of dynamics, inertial, structural, and impact/contact, make the problem quite complex to analyse. As a result, some of the most important problems with valvetrains are only surmised at, rather than fundamentally understood. The multiphysics modelling approach proposed in this paper renders a better understanding, as well as conforming to experimental observations.