【摘要】 基于通用计算流体动力学(computational fluid dynamics,CFD)求解器和自编制三维非线性壳体有限元程序,发展一种用于解决三维弹性薄壁结构与粘性流体相互作用问题的数值方法.用CFD求解器Fluent求解粘性流体流动,采用基于三维薄壳非线性理论建立的有限元程序来求解薄壁结构的变形,通过交错方法实现流体和结构的耦合.考察三维非线性壳体有限元程序在解决屈曲和后屈曲问题时的可靠性;通过求解可塌陷直管和粘性流体相互作用问题,检验流固耦合方法的可靠性;研究呼气过程中可塌陷分叉肺管和气流的相互作用问题.重点考察分叉结构中可塌陷管和不同雷诺数流动之间的相互影响.更多还原

【Abstract】 Using a computational fluid dynamics(CFD) solver and the 3D nonlinear shell finite element code developed by the authors,a numerical method for the interactions between 3D thin-walled structure and fluid was proposed.The viscous flow was solved using the CFD solver,Fluent,while the large deformation of thin-walled structure was solved by the 3D nonlinear shell-based finite element code.The staggered method was used to couple the fluid and the structure.First,a benchmark problem was used to verify the reliability of the finite element code in solving buckling and post-buckling behaviors of thin-walled structures.Second,a problem with a collapsible tube conveying viscous fluid was simulated.The good agreement between the results obtained by the present method and those published in literatures shows the reliability of the present method in dealing with the interactions of thin-walled structure and viscous fluid.Finally,the interaction of fluid and structure in forced expiration was investigated.The emphasis of the project was laid on the effect between collapsible tube and viscous flow in bifurcating airways.更多还原