自由活塞式内燃发电机振动特性  

Oscillation Characteristic of a Free Piston Linear Alternator

作　　者：李庆峰[1] 朱皓月[1] 肖进[1] 黄震[1] 

机构地区：[1]上海交通大学动力机械与工程教育部重点实验室,上海200240

出　　处：《内燃机学报》2009年第4期370-374,共5页Transactions of Csice

基　　金：国家自然科学基金资助项目(50806046)

摘　　要：对自由活塞式内燃发电机建立了数学模型,理论上阐述了自由活塞的运动特性并对应制作了该系统的固有频率特性脉谱图;利用Matlab/Simulink建立了该系统仿真模型,分析讨论了自由活塞的实际运动规律,并与上述理论解进行了对比、分析。研究结果表明,自由活塞式内燃发电机的活塞运动不同于传统旋转内燃机,它可视为变阻尼、变刚度的单自由度受迫振动,振动频率与外部周期性燃烧激励相关联;此外,由于该系统的等效刚度系数以及阻尼系数均为正数,它对周期性激励表现出的响应最终稳定收敛进而保障内燃机稳定运行。该结果有利于进一步掌握自由活塞式内燃发电机的运动特性,并为实际样机设计提供了理论依据。A mathematical model of a free piston linear engine is established. Motion characteristics and natural frequency map of the free piston are established. The motion characteristics are explained from the oscillation point. Simulation model is built up in Matlab/Simulink and the motion characteristics are analyzed. The results show that the free piston system has some unique features which are different from those of traditional Internal Combustion （IC） engines. It could be regarded as a forced vibration system with variable damping coefficient and stiffness. And the coefficients of damping and stiffness of the system are both positive. Its steady state response of periodical excitation is convergent which means that the system is stable under the periodical combustion. The built model provides a foundation for the design and improvement for free piston linear alternator.

关 键 词：自由活塞 内燃机 受迫振动 振动特性 频率 

分 类 号：TK441[动力工程及工程热物理—动力机械及工程]