The nonlinear aeroelastic response of a two-degree-of-freedom airfoil with freeplay and cubic nonlinearities in supersonic flows is investigated. The second-order piston theory is used to analyze a double-wedge airfoi...The nonlinear aeroelastic response of a two-degree-of-freedom airfoil with freeplay and cubic nonlinearities in supersonic flows is investigated. The second-order piston theory is used to analyze a double-wedge airfoil. Then, the fold bifurcation and the amplitude jump phenomenon are detected by the averaging method and the multi-variable Floquet theory. The analyticall results are further verified by numerical simulations. Finally, the influence of the freeplay parameters on the aeroelastic response is analyzed in detail.展开更多
In this paper,the phenomenon on collapsible tube displacement oscillation,a new behavior of the collapsible tube puisatile flow has been studied.The experiments show that the collapsible tube,in which the flow is peri...In this paper,the phenomenon on collapsible tube displacement oscillation,a new behavior of the collapsible tube puisatile flow has been studied.The experiments show that the collapsible tube,in which the flow is periodic puisatile in the upstream,will oscillate as a simple supported beam when it is collapsed to certain extent,and that if the tube is collapsed continue,this oscillation will tend to weak and completely disappear lastly.An analytical model corresponding to the collapsible tube displacement oscillation and its governed equations are set up from the experiment background.By analysing the model and solving the equations, the collapsible tube displacement oscillation pattern and the oscillation occurring or disappearing criterion are obtained.The results predicted by this study are in agreement with those observed from experiment phenomena.展开更多
文摘The nonlinear aeroelastic response of a two-degree-of-freedom airfoil with freeplay and cubic nonlinearities in supersonic flows is investigated. The second-order piston theory is used to analyze a double-wedge airfoil. Then, the fold bifurcation and the amplitude jump phenomenon are detected by the averaging method and the multi-variable Floquet theory. The analyticall results are further verified by numerical simulations. Finally, the influence of the freeplay parameters on the aeroelastic response is analyzed in detail.
文摘In this paper,the phenomenon on collapsible tube displacement oscillation,a new behavior of the collapsible tube puisatile flow has been studied.The experiments show that the collapsible tube,in which the flow is periodic puisatile in the upstream,will oscillate as a simple supported beam when it is collapsed to certain extent,and that if the tube is collapsed continue,this oscillation will tend to weak and completely disappear lastly.An analytical model corresponding to the collapsible tube displacement oscillation and its governed equations are set up from the experiment background.By analysing the model and solving the equations, the collapsible tube displacement oscillation pattern and the oscillation occurring or disappearing criterion are obtained.The results predicted by this study are in agreement with those observed from experiment phenomena.
