Piezoelectric Vibration Control within Whole Engine Design

Kurzfassung

In consequence of unbalance forces related to rotor dynamics vibrations are induced. For the purpose of investigating the applicability of an active vibration control under dynamic operating conditions within the engine and the engine design process, respectively, a simulation based method is developed. Moreover, the influence of varying temperatures on the piezoelectric material is investigated and the feasibility of active vibration control via piezoelectric actuators is demonstrated for specific operating conditions. Based on experimental data from literature the temperature dependencies for relevant elastic and electric material parameters are derived. Subsequently, these dependencies are included in an adequate temperature dependent piezoelectric material model and implemented within simulations conducted with the commercial FE(finite element)-software ANSYS. Accordingly, harmonic re-sponse analyses of a generic engine model incorporating rotor dynamics are accomplished. In order to reduce the computational effort an FE-model of the engine is build up by using the super element technology. Further, a proper optimization process is set-up by use of the commercial tool MODE FRONTIER. The optimal design of the piezoelectric vibration control is found by minimizing two objective functions. Firstly, the displacement of the engine rotor shaft is to be reduced. Secondly, a reduction of the reaction forces within the engine rotor bearing is to be achieved. Four parameters of the piezoelectric actuators, two electric and two geometric parameters, are identified to be the most influential for this design process. Consequently, the optimization is carried out by using a multi-objective genetic algorithm. Finally, the integration of piezoelectric analyses into the overall design process is shown for a generic engine model. In conclusion, the integration of piezoelectric vibration control design into the overall design process is shown for a generic engine model. Additionally, a trade-off is revealed between the two objective functions for varying temperatures.