为解决自由活塞膨胀机的关键部件活塞在高温气体及机械交变载荷下存在的热应力集中、热变形不均及疲劳寿命较低等问题,通过构建几何模型与网格划分,设置流场、热场边界条件,采用热-流-固耦合方法进行有限元分析。结合名义应力法与材料应...为解决自由活塞膨胀机的关键部件活塞在高温气体及机械交变载荷下存在的热应力集中、热变形不均及疲劳寿命较低等问题,通过构建几何模型与网格划分,设置流场、热场边界条件,采用热-流-固耦合方法进行有限元分析。结合名义应力法与材料应力-循环次数(stress-number of cycles,S-N)曲线预测疲劳寿命,发现活塞缓冲区与头部问题显著;进而通过设置环槽、将活塞厚度从10 mm增至20 mm、合理去除活塞中部结构等方式进行结构优化。模拟验证结果表明,优化后活塞热应力降低,局部变形得到有效抑制,疲劳寿命提升,自由活塞膨胀机运行稳定性与可靠性增强,为其实际工程高效应用提供有力支撑。展开更多
The analysis of the characteristics of the cushion process of the pneumatic cushion cylinder is presented, and the nonlinear model of pneumatic cushion cylinders is built in the form of nonlinear differential equation...The analysis of the characteristics of the cushion process of the pneumatic cushion cylinder is presented, and the nonlinear model of pneumatic cushion cylinders is built in the form of nonlinear differential equations. Besides, through the simulation of the pressure in the cushion chamber, the characteristics of the pneumatic cushion cylinder are obtained, which helps to understand the performance of the pneumatic cushion cylinder and improve or design the better cushion structure.展开更多
文摘为解决自由活塞膨胀机的关键部件活塞在高温气体及机械交变载荷下存在的热应力集中、热变形不均及疲劳寿命较低等问题,通过构建几何模型与网格划分,设置流场、热场边界条件,采用热-流-固耦合方法进行有限元分析。结合名义应力法与材料应力-循环次数(stress-number of cycles,S-N)曲线预测疲劳寿命,发现活塞缓冲区与头部问题显著;进而通过设置环槽、将活塞厚度从10 mm增至20 mm、合理去除活塞中部结构等方式进行结构优化。模拟验证结果表明,优化后活塞热应力降低,局部变形得到有效抑制,疲劳寿命提升,自由活塞膨胀机运行稳定性与可靠性增强,为其实际工程高效应用提供有力支撑。
文摘The analysis of the characteristics of the cushion process of the pneumatic cushion cylinder is presented, and the nonlinear model of pneumatic cushion cylinders is built in the form of nonlinear differential equations. Besides, through the simulation of the pressure in the cushion chamber, the characteristics of the pneumatic cushion cylinder are obtained, which helps to understand the performance of the pneumatic cushion cylinder and improve or design the better cushion structure.
