非对称气体弹簧谐振系统建模与分析

Nonlinear Modelling and Analysis of Reciprocating System with Asymmetric Gas Springs

气体弹簧支撑的谐振系统广泛应用于自由活塞斯特林发动机、压缩机等。以非对称气体弹簧谐振系统为研究对象,在直线电机驱动条件下,考虑谐振系统复杂流道内准稳态和间歇瞬态振荡流动、多处活塞-气缸密封间隙内气体流动,通过谐振系统非线性建模与数值计算,得到谐振系统活塞位移、各气腔气体压力变化规律等动态特性。在此基础上,基于时频变换分析谐振系统气体弹簧刚度特性,得到非对称气体弹簧等效刚度计算解析式。数值计算结果与实验结果吻合良好,验证了谐振系统建模与计算的正确性,能够为气体弹簧支撑往复式机器的设计提供参考。

The reciprocating system supported by gas springs are widely used in engineering,such as free-piston Stirling engine,compressors,etc.Focusing on dynamic behavior of the reciprocating system with asymmetric gas springs in Linear Alternator(LA)-driven mode,a nonlinear dynamic model considering stable and intermittent gas flows in pipelines and sealing gaps is established,the dynamic characteristics are obtained through numerical calculation.Furthermore,equivalent stiffness characteristics of asymmetric gas springs of the reciprocating system are obtained and analyzed based on time-frequency domain transformation.The nonlinear dynamic model is proved to be valid based on comparison with experimental measurements.The modelling and analysis results can provide theoretical basis and guidance for the design of the reciprocating system applied to reciprocating machinery.