The pulsations and translations of cavitation bubbles obey combined ordinary differential equations,and their nonlinearities are studied by the bifurcation diagram and the phase diagram in a strong ultrasonic field.Bu...The pulsations and translations of cavitation bubbles obey combined ordinary differential equations,and their nonlinearities are studied by the bifurcation diagram and the phase diagram in a strong ultrasonic field.Bubble pulsation can change regularly or irregularly with changing driving pressure in the time domain.The bifurcation diagrams of the pulsation versus driving pressure show that the pulsations and translations of bubbles have nonlinear characteristics,and the nonlinear translations of bubbles can disorder the pulsations for certain parameters.Disorder of the pulsation can also be caused by nonlinear pulsation itself.In addition,the phase diagrams also show that the nonlinear translations make a large contribution to the pulsations.The same result can also be obtained when the ambient radii of two bubbles are different.展开更多
In this study,underwater explosion tests with 2.5 g trinitrotoluene explosive under different fixed plates with prefabricated holes were conducted.The experimental results showed that the air inflow from the prefabric...In this study,underwater explosion tests with 2.5 g trinitrotoluene explosive under different fixed plates with prefabricated holes were conducted.The experimental results showed that the air inflow from the prefabricated hole caused the bubble to collapse earlier with an increase in the hole diameter.In addition,the deformation mode of the thin plate transitioned from“convex”to“concave”(up to down).Next,the coupled Eulerian-Lagrangian method was used to perform the corresponding numerical simulation.The accuracy of the numerical simulation method was verified through a comparison with the experimental data.In addition,a series of numerical simulations were conducted with different prefabricated-hole diameters,blast distances,and prefabricated-hole shapes.The results showed that the bubble-pulsating water jet substantially influenced the deformation of the thin plate when the diameter of the prefabricated hole was within the theoretical maximum bubble radius.When the blast distance was within the theoretical maximum bubble radius,the thin plate was subjected to only a single bubble pulsation owing to the air inflow from the prefabricated hole.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.12074185).
文摘The pulsations and translations of cavitation bubbles obey combined ordinary differential equations,and their nonlinearities are studied by the bifurcation diagram and the phase diagram in a strong ultrasonic field.Bubble pulsation can change regularly or irregularly with changing driving pressure in the time domain.The bifurcation diagrams of the pulsation versus driving pressure show that the pulsations and translations of bubbles have nonlinear characteristics,and the nonlinear translations of bubbles can disorder the pulsations for certain parameters.Disorder of the pulsation can also be caused by nonlinear pulsation itself.In addition,the phase diagrams also show that the nonlinear translations make a large contribution to the pulsations.The same result can also be obtained when the ambient radii of two bubbles are different.
基金supported by the National Natural Science Foundation of China(Grant No.12172178).
文摘In this study,underwater explosion tests with 2.5 g trinitrotoluene explosive under different fixed plates with prefabricated holes were conducted.The experimental results showed that the air inflow from the prefabricated hole caused the bubble to collapse earlier with an increase in the hole diameter.In addition,the deformation mode of the thin plate transitioned from“convex”to“concave”(up to down).Next,the coupled Eulerian-Lagrangian method was used to perform the corresponding numerical simulation.The accuracy of the numerical simulation method was verified through a comparison with the experimental data.In addition,a series of numerical simulations were conducted with different prefabricated-hole diameters,blast distances,and prefabricated-hole shapes.The results showed that the bubble-pulsating water jet substantially influenced the deformation of the thin plate when the diameter of the prefabricated hole was within the theoretical maximum bubble radius.When the blast distance was within the theoretical maximum bubble radius,the thin plate was subjected to only a single bubble pulsation owing to the air inflow from the prefabricated hole.
