When it is generated in extreme vicinity to a water surface,an oscillating bubble bursts into the atmosphere and high-pressure gas is simultaneously exhausted from it,forming a splash sheet and an open cavity.The dyna...When it is generated in extreme vicinity to a water surface,an oscillating bubble bursts into the atmosphere and high-pressure gas is simultaneously exhausted from it,forming a splash sheet and an open cavity.The dynamics of the splash sheet induced by the bursting of the oscillating bubble has drawn increasing attention,but it is not clearly understood.We conduct a numerical simulation in the framework of open-source software OpenFOAM.The volume of fluid and Reynolds-Averaged Navier-Stokes methods are used to precisely capture the gas-liquid interface and obtain flow structure,respectively.In addition,an experimental setup is carried out based on an object distance compensation method for validation of the numerical model.Two patterns are summarized:(1)An open splash,(2)A sealed splash depending on whether a splash sheet completely closes.Detailed numerical results shows that the bubble bursting is induced by the Rayleigh-Taylor instability.Finally,the splash closures are discussed for two patterns.展开更多
Nano-injection molding enables the formation of nano-scale anchors to connect heterogeneous material surfaces to achieve the required mechanical properties.In this work,polyphenylene sulfide(PPS),aluminum(Al),copper(C...Nano-injection molding enables the formation of nano-scale anchors to connect heterogeneous material surfaces to achieve the required mechanical properties.In this work,polyphenylene sulfide(PPS),aluminum(Al),copper(Cu),and iron(Fe)were selected as candidate polymer and metal materials.Three kinds of polymer-metal interfacial models with pyramidal nano-slots were modeled.The molecular dynamics simulations were launched to investigate the adhesion properties and molecular kinematic mechanisms of heterogeneous interfaces in nanoinjection molding.Results showed that the wall-slipping behavior of PPS at the interface slot was obvious,it was easy to form multiple-anchorpoints in the central area of substrates,and these anchor points were easily slipping along the wall,different from the de Gennes model.The atomic lattice and atomic band gap of metal affected the adhesion strength.The BCC lattice of Fe was more suitable for nano-injection molding process than the FCC lattice of Al and Cu.The filling rate,interfacial energy,the tensile and shear failures data revealed that the interfacial adhesion performances decreased according to the following order,Fe-PPS,Cu-PPS and Al-PPS components,respectively,and the interface failure mode was closely related to the stress loading mode.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12293000,12293003,12293004,12122214,12202291 and 12272382)the Youth Innovation Promotion Association CAS(Grant No.2022019).
文摘When it is generated in extreme vicinity to a water surface,an oscillating bubble bursts into the atmosphere and high-pressure gas is simultaneously exhausted from it,forming a splash sheet and an open cavity.The dynamics of the splash sheet induced by the bursting of the oscillating bubble has drawn increasing attention,but it is not clearly understood.We conduct a numerical simulation in the framework of open-source software OpenFOAM.The volume of fluid and Reynolds-Averaged Navier-Stokes methods are used to precisely capture the gas-liquid interface and obtain flow structure,respectively.In addition,an experimental setup is carried out based on an object distance compensation method for validation of the numerical model.Two patterns are summarized:(1)An open splash,(2)A sealed splash depending on whether a splash sheet completely closes.Detailed numerical results shows that the bubble bursting is induced by the Rayleigh-Taylor instability.Finally,the splash closures are discussed for two patterns.
基金financially supported by the National Natural Science Foundation of China(No.52165046)。
文摘Nano-injection molding enables the formation of nano-scale anchors to connect heterogeneous material surfaces to achieve the required mechanical properties.In this work,polyphenylene sulfide(PPS),aluminum(Al),copper(Cu),and iron(Fe)were selected as candidate polymer and metal materials.Three kinds of polymer-metal interfacial models with pyramidal nano-slots were modeled.The molecular dynamics simulations were launched to investigate the adhesion properties and molecular kinematic mechanisms of heterogeneous interfaces in nanoinjection molding.Results showed that the wall-slipping behavior of PPS at the interface slot was obvious,it was easy to form multiple-anchorpoints in the central area of substrates,and these anchor points were easily slipping along the wall,different from the de Gennes model.The atomic lattice and atomic band gap of metal affected the adhesion strength.The BCC lattice of Fe was more suitable for nano-injection molding process than the FCC lattice of Al and Cu.The filling rate,interfacial energy,the tensile and shear failures data revealed that the interfacial adhesion performances decreased according to the following order,Fe-PPS,Cu-PPS and Al-PPS components,respectively,and the interface failure mode was closely related to the stress loading mode.
