基于活塞作用下的管内气流脉动特性

Effect of Piston Structure on Disturbance Characteristics of Uniform Velocity Airflow

【目的】研究气流管路中活塞运动对气流的扰动机理,探讨机械能转化成脉动能的转化规律及效率。【方法】建立活塞对管内气流作用的物理与数学模型,运用数值模拟方法研究不同工况下的活塞运动对匀速气流的扰动特性,分析不同进口气流速度、活塞运动振幅及频率对匀速气流的扰动规律。【结果与结论】活塞往复运动能有效使管路内匀速气流产生脉动。管路内气流脉动振幅及频率不受其进口速度的影响。活塞运动振幅与气流脉动振幅呈线性关系,随着活塞振幅的增加脉动传导效率逐渐下降,脉动传导效率均在80%以上,效率最高可达99.20%。气流脉动与活塞运动同频率变化。

【Objective】The study is to investigate the disturbance mechanism of piston movement on air flow,and to explore the conversion law and efficiency of mechanical energy into pulsating energy.【Method】The process of creating pulsating airflow by piston motion was studied by numerical simulation,and the physical and mathematical models of the piston action on airflow in the tube were established.The disturbance law of uniform airflow by different inlet speed,piston motion amplitude and frequency was analyzed.【Result and Conclusion】The piston reciprocating motion can effectively pulsate the uniform airflow in the pipeline.The amplitude and frequency of airflow pulsation in the pipeline are not affected by its inlet speed.The piston motion amplitude and airflow pulsation amplitude are linearly related.The pulsation conduction efficiency is above 80%,gradually decreasing with the increase of piston amplitude,with the maximum efficiency up to 99.20%.The airflow pulsation changes with the same frequency as the piston motion.