The shock tube experiments of inclined air/SF6 interface instability under the shock wave with the Mach numbers 1.23 and 1.41 are conducted. The numerical simulation is done with the parallel algorithm and the multi-v...The shock tube experiments of inclined air/SF6 interface instability under the shock wave with the Mach numbers 1.23 and 1.41 are conducted. The numerical simulation is done with the parallel algorithm and the multi-viscous-fluid and turbulence （MVFT） code of the large-eddy simulation （LES）. The developing process of the interface accelerated by the shock wave is reproduced by the simulations. The complex wave structures, e.g., the propagation, refraction, and reflection of the shock wave, are clearly revealed in the flows. The simulated evolving images of the interface are consistent with the experimental ones. The simulated width of the turbulent mixing zone （TMZ） and the displacements of the bubble and the spike also agree well with the experimental data. Also, the reliability and effectiveness of the MVFT in simulating the problem of interface instability are validated. The more energies are injected into the TMZ when the shock wave has a larger Mach number. Therefore, the perturbed interface develops faster.展开更多
The morphological stability of a planar interface with different crystallographic orientations is studied under a small positive temperature gradient using a transparent model alloy of succinonitrile. Novel experiment...The morphological stability of a planar interface with different crystallographic orientations is studied under a small positive temperature gradient using a transparent model alloy of succinonitrile. Novel experimental apparatus is constructed to provide a temperature gradient of about 0.37 K/mm. Under this small temperature gradient, the planar interface instability depends largely on the crystallographic orientation. It is shown experimentally that the effect of interfacial energy anisotropy on planar interface stability cannot be neglected even in a small temperature gradient system. Higher interfacial energy anisotropy leads the planar interface to become more unstable, which is different from the stabilizing effect of the interfacial energy on the planar interface. The experimental results are in agreement with previous theoretical calculations and phase field simulations.展开更多
Solid-state lithium batteries(SSLBs)with high safety have emerged to meet the increasing energy density demands of electric vehicles,hybrid electric vehicles,and portable electronic devices.However,the dendrite format...Solid-state lithium batteries(SSLBs)with high safety have emerged to meet the increasing energy density demands of electric vehicles,hybrid electric vehicles,and portable electronic devices.However,the dendrite formation,high interfacial resistance,and deleterious interfacial reactions caused by solid-solid contact between electrode and electrolyte have hindered the commercialization of SSLBs.Thus,in this review,the state-of-the-art developments in the rational design of solid-state electrolyte and their progression toward practical applications are reviewed.First,the origin of interface instability and the sluggish charge carrier transportation in solid-solid interface are presented.Second,various strategies toward stabilizing interfacial stability(reducing interfacial resistance,suppressing lithium dendrites,and side reactions)are summarized from the physical and chemical perspective,including building protective layer,constructing 3D and gradient structures,etc.Finally,the remaining challenges and future development trends of solidstate electrolyte are prospected.This review provides a deep insight into solving the interfacial instability issues and promising solutions to enable practical high-energy-density lithium metal batteries.展开更多
The Kelvin-Helmholtz instability is believed to be the dominant instability mechanism for free shear flows at large Reynolds numbers. At small Reynolds numbers, a new instability mode is identified when the temporal i...The Kelvin-Helmholtz instability is believed to be the dominant instability mechanism for free shear flows at large Reynolds numbers. At small Reynolds numbers, a new instability mode is identified when the temporal instability of parallel viscous two fluid mixing layers is extended to current-fluid mud systems by considering a composite error function velocity profile. The new mode is caused by the large viscosity difference between the two fluids. This interfacial mode exists when the fluid mud boundary layer is sufficiently thin. Its performance is different from that of the Kelvin-Helmholtz mode. This mode has not yet been reported for interface instability problems with large viscosity contrasts. These results are essential for further stability analysis of flows relevant to the breaking up of this type of interface.展开更多
The Richtmyer-Meshkov instability ofa ‘V＇ shaped air/helium gaseous interface subjected to a weak shock wave is experimentally studied. A soap film technique is adopted to create a ‘V＇ shaped interface with accura...The Richtmyer-Meshkov instability ofa ‘V＇ shaped air/helium gaseous interface subjected to a weak shock wave is experimentally studied. A soap film technique is adopted to create a ‘V＇ shaped interface with accurate initial conditions. Five kinds of ‘V＇ shaped interfaces with different vertex angles are formed to highlight the effects of initial conditions on the flow characteristics. The results show that a spike is generated after the shock impact, and grows constantly with time. As the vertex angle increases, vortices generated on the interface become less noticeable, and the spike develops less pronouncedly. The linear growth rate of interface width after compression phase is estimated by a linear model and a revised linear model, and the latter is proven to be more effective for the interface with high initial amplitudes. The linear growth rate of interface width is, for the first time in a heavy/light interface configuration, found to be a non-monotonous function of the initial perturbation amplitude-wavelength ratio.展开更多
Some of the main progress on the investigation of the mechanism of the wave formation in explosive welding at the Institute of Mechanics is summarized and otters'previous works are re- viewed.Our systematic experi...Some of the main progress on the investigation of the mechanism of the wave formation in explosive welding at the Institute of Mechanics is summarized and otters'previous works are re- viewed.Our systematic experiments and analysis do not substantiate the theory of wave formation based on Karman vortex-street analogy or Helmholtz instability.On the contrary,they show that materi- al strength insensitive to strain rate plays an important role.A simple hydro-plastic model is presented to explain the main features regarding the interracial wave formation and to estimate the magnitude of wave length.The result is in broad agreement with experiment.展开更多
The wavy interface for similar or the same metal explosive welding（EXW） and the universal mechanism of wavy interface formation in EXW were studied in this work. Based on a new established model, it was deduced that...The wavy interface for similar or the same metal explosive welding（EXW） and the universal mechanism of wavy interface formation in EXW were studied in this work. Based on a new established model, it was deduced that the evolution frequencies of the instability were constrained in a limited range. Then experiments of identical metal EXW were performed and welding interfaces were characterized for examining the final morphology. By calculating the fractal dimensions and multifractal spectra of welding interface, the fractal characteristics of interface were revealed and a quantitative description was achieved for EXW interface structure. Thus, the formation, evolution and final morphology of wavy interface were systemically researched.展开更多
The characteristic of the surface morphology of primary α phase was studied in a deformed near-α tita- nium alloy. Dendritic α phase emerged on the surfaces of primary α phase when the alloy was air-cooled in α ...The characteristic of the surface morphology of primary α phase was studied in a deformed near-α tita- nium alloy. Dendritic α phase emerged on the surfaces of primary α phase when the alloy was air-cooled in α ＋β phase field after deformation. The dendritic α grain has the same orientation with its original primary α grain. The formation of the dendritic α phase could be explained by interface instability in epi- taxial growth process of the primary α phase. The dislocations induced by deformation could facilitate the formation of dendritic α phase leading to the dendritic α phase and more obvious with the increase of strain. The growth of dendritic α phase was finally limited by the nucleation of second α phase with cooling.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 11072228 and 11002129)
文摘The shock tube experiments of inclined air/SF6 interface instability under the shock wave with the Mach numbers 1.23 and 1.41 are conducted. The numerical simulation is done with the parallel algorithm and the multi-viscous-fluid and turbulence （MVFT） code of the large-eddy simulation （LES）. The developing process of the interface accelerated by the shock wave is reproduced by the simulations. The complex wave structures, e.g., the propagation, refraction, and reflection of the shock wave, are clearly revealed in the flows. The simulated evolving images of the interface are consistent with the experimental ones. The simulated width of the turbulent mixing zone （TMZ） and the displacements of the bubble and the spike also agree well with the experimental data. Also, the reliability and effectiveness of the MVFT in simulating the problem of interface instability are validated. The more energies are injected into the TMZ when the shock wave has a larger Mach number. Therefore, the perturbed interface develops faster.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 50971102 and 50901061)the National Basic Research Program of China (Grant No. 2011CB610402)+2 种基金the Fund of the State Key Laboratory of Solidification Processing in Northwestern Polytechnical University,China (Grant Nos. 02-TZ-2008 and 36-TP-2009)the Programme of Introducing Talents of Discipline to Universities,China (Grant No. 08040)the National Science Foundation for Post-doctoral Scientists of China(Grant No. 20110491689)
文摘The morphological stability of a planar interface with different crystallographic orientations is studied under a small positive temperature gradient using a transparent model alloy of succinonitrile. Novel experimental apparatus is constructed to provide a temperature gradient of about 0.37 K/mm. Under this small temperature gradient, the planar interface instability depends largely on the crystallographic orientation. It is shown experimentally that the effect of interfacial energy anisotropy on planar interface stability cannot be neglected even in a small temperature gradient system. Higher interfacial energy anisotropy leads the planar interface to become more unstable, which is different from the stabilizing effect of the interfacial energy on the planar interface. The experimental results are in agreement with previous theoretical calculations and phase field simulations.
基金supported by the National Key R&D Program(2022YFE0206400)the National Natural Science Foundation of China(52202256)+4 种基金the Natural Science Foundation of Jiangsu Province of China(BK20220612)the Science and Technology Development Fund,Macao SAR(0096/2020/A2,0013/2021/AMJ,and 0082/2022/A2)the Opening Project of the Key Laboratory of Jiangsu Province for Silk Engineering,Soochow University(KJS2277)the funds from Jiangsu University“Qinglan Project”the Young Elite Scientists Sponsorship Program of the Jiangsu Association for Science and Technology
文摘Solid-state lithium batteries(SSLBs)with high safety have emerged to meet the increasing energy density demands of electric vehicles,hybrid electric vehicles,and portable electronic devices.However,the dendrite formation,high interfacial resistance,and deleterious interfacial reactions caused by solid-solid contact between electrode and electrolyte have hindered the commercialization of SSLBs.Thus,in this review,the state-of-the-art developments in the rational design of solid-state electrolyte and their progression toward practical applications are reviewed.First,the origin of interface instability and the sluggish charge carrier transportation in solid-solid interface are presented.Second,various strategies toward stabilizing interfacial stability(reducing interfacial resistance,suppressing lithium dendrites,and side reactions)are summarized from the physical and chemical perspective,including building protective layer,constructing 3D and gradient structures,etc.Finally,the remaining challenges and future development trends of solidstate electrolyte are prospected.This review provides a deep insight into solving the interfacial instability issues and promising solutions to enable practical high-energy-density lithium metal batteries.
基金supported by the National Natural Science Foundation of China (Grants 11172307, 11232012 11572332)973 Program (Grant 2014CB046200)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant XDB22040203)
文摘The Kelvin-Helmholtz instability is believed to be the dominant instability mechanism for free shear flows at large Reynolds numbers. At small Reynolds numbers, a new instability mode is identified when the temporal instability of parallel viscous two fluid mixing layers is extended to current-fluid mud systems by considering a composite error function velocity profile. The new mode is caused by the large viscosity difference between the two fluids. This interfacial mode exists when the fluid mud boundary layer is sufficiently thin. Its performance is different from that of the Kelvin-Helmholtz mode. This mode has not yet been reported for interface instability problems with large viscosity contrasts. These results are essential for further stability analysis of flows relevant to the breaking up of this type of interface.
基金supported by the National Natural Science Foundation of China(U1530103,11302219,and 11272308)
文摘The Richtmyer-Meshkov instability ofa ‘V＇ shaped air/helium gaseous interface subjected to a weak shock wave is experimentally studied. A soap film technique is adopted to create a ‘V＇ shaped interface with accurate initial conditions. Five kinds of ‘V＇ shaped interfaces with different vertex angles are formed to highlight the effects of initial conditions on the flow characteristics. The results show that a spike is generated after the shock impact, and grows constantly with time. As the vertex angle increases, vortices generated on the interface become less noticeable, and the spike develops less pronouncedly. The linear growth rate of interface width after compression phase is estimated by a linear model and a revised linear model, and the latter is proven to be more effective for the interface with high initial amplitudes. The linear growth rate of interface width is, for the first time in a heavy/light interface configuration, found to be a non-monotonous function of the initial perturbation amplitude-wavelength ratio.
文摘Some of the main progress on the investigation of the mechanism of the wave formation in explosive welding at the Institute of Mechanics is summarized and otters'previous works are re- viewed.Our systematic experiments and analysis do not substantiate the theory of wave formation based on Karman vortex-street analogy or Helmholtz instability.On the contrary,they show that materi- al strength insensitive to strain rate plays an important role.A simple hydro-plastic model is presented to explain the main features regarding the interracial wave formation and to estimate the magnitude of wave length.The result is in broad agreement with experiment.
基金Funded by the National Natural Science Foundation of China(Nos.11202093 and 11662010)
文摘The wavy interface for similar or the same metal explosive welding（EXW） and the universal mechanism of wavy interface formation in EXW were studied in this work. Based on a new established model, it was deduced that the evolution frequencies of the instability were constrained in a limited range. Then experiments of identical metal EXW were performed and welding interfaces were characterized for examining the final morphology. By calculating the fractal dimensions and multifractal spectra of welding interface, the fractal characteristics of interface were revealed and a quantitative description was achieved for EXW interface structure. Thus, the formation, evolution and final morphology of wavy interface were systemically researched.
文摘The characteristic of the surface morphology of primary α phase was studied in a deformed near-α tita- nium alloy. Dendritic α phase emerged on the surfaces of primary α phase when the alloy was air-cooled in α ＋β phase field after deformation. The dendritic α grain has the same orientation with its original primary α grain. The formation of the dendritic α phase could be explained by interface instability in epi- taxial growth process of the primary α phase. The dislocations induced by deformation could facilitate the formation of dendritic α phase leading to the dendritic α phase and more obvious with the increase of strain. The growth of dendritic α phase was finally limited by the nucleation of second α phase with cooling.
