Dynamics of a parametric N-pendulum with a view on energy harvesting from the motion of a reciprocating oil pumping unit

FRANCO EZEQUIEL DOTTI; FLORENCIA REGUERA; SEBASTIÁN PABLO MACHADO; SANTIAGO MANUEL OSINAGA; CARLOS ALBERTO VERA

Búzios, Brasil

Congreso; DINAME 2019: XVIII International Symposium on Dynamic Problems of Mechanics; 2019

Associação Brasileira de Métodos Computacionais em Engenharia

The nonlinear dynamics of a parametric pendulum system excited by the motion of a reciprocating oil pumping unit is explored. The final goal of this investigation is to recover energy from such machines by means of pendulum harvesters located on a walking beam. Being the parametric pendulum a potential well system, the study is concentrated in rotational responses which are the most energetic state. A pendulum with multiple concentric masses, i.e. a N-pendulum, is considered in the design. This provides versatility, since it allows the tuning of the natural frequency of the system. The nodding motion provided by the pumping unit is a planar motion, thus containing both vertical and horizontal components. Such feature has a strong influence in the dynamics of the system, as introduces an asymmetry in the governing equation. It is shown that, by virtue of this asymmetry, the pendulum system experiences a complex rotational behavior, very different to the widely studied classic parametric pendulum with a sinusoidal forcing.