Periodic response and stability of reciprocating engines

摘要

Periodic steady state response and stability of reciprocating engine models is captured directly, by applying appropriate numerical methodologies. First, small-scale models of single-cylinder engines are examined. The set of equations of motion derived is strongly nonlinear due to the rigid body rotation of the crank and the connecting rod, as well as due to the nonlinearities associated with the bearing action and the fact that both the driving and the resisting loads are expressed as a function of the crank rotation. Subsequently, the same methodologies are extended and applied to a much more complicated model of a four-cylinder in-line engine. Both the crankshaft and the engine block are discretized by finite elements, resulting in a large-scale system. In all cases, the influence of the system parameters on its long time response and stability can be studied in a systematic and effective way.