A multicomponent thermal multi-relaxation-time(MRT)lattice Boltzmann method(LBM)is presented to study collapsing cavitation bubble.The simulation results satisfy Laplace law and the adiabatic law,and are consistent wi...A multicomponent thermal multi-relaxation-time(MRT)lattice Boltzmann method(LBM)is presented to study collapsing cavitation bubble.The simulation results satisfy Laplace law and the adiabatic law,and are consistent with the numerical solution of the Rayleigh-Plesset equation.To study the effects of the non-condensable gas inside bubble on collapsing cavitation bubble,a numerical model of single spherical bubble near a solid wall is established.The temperature and pressure evolution of the two-component two-phase flow are well captured.In addition,the collapse process of the cavitation bubble is discussed elaborately by setting the volume fractions of the gas and vapor to be the only variables.The results show that the non-condensable gas in the bubble significantly affects the pressure field,temperature field evolution,collapse velocity,and profile of the bubble.The distinction of the pressure and temperature on the wall after the second collapse becomes more obvious as the non-condensable gas concentration increases.展开更多
According to the atmospheric pressure plasma(APP)technology,we propose a rapid synthetic approach of the substrates for enhanced Raman spectroscopy.The plasma is used to modify and etch the surface of silver film,whic...According to the atmospheric pressure plasma(APP)technology,we propose a rapid synthetic approach of the substrates for enhanced Raman spectroscopy.The plasma is used to modify and etch the surface of silver film,which generates large scale hotspots'aggregation.By switching the discharge polarity and adjusting the film thickness,different surface morphologies are formed due to the oxidation,reactive etch and accumulation of the plasma product in a certain space.Especially under positive corona discharge condition,dense snake-like microstructures are formed by the gradual connection of individual nanoparticles,which are driven by the influence of the electric field on surface diffusion.In addition,the experiments verify that the corresponding enhancement factor(EF)raises at least five orders of magnitude and the treatment time is about 10 min.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11874140 and 11574072)the State Key Laboratory of Acoustics,Chinese Academy of Sciences(Grant No.SKLA201913)+3 种基金the National Key Research and Development Program of China(Grant No.2016YFC0401600)the Primary Research and Development Plan of Jiangsu Province,China(Grant No.BE2016056)the Postgraduate Research&Practice Innovation Program of Jiangsu Province,China(Grant Nos.2018B741X14 and KYCX180552)the Postgraduate Research&Practice Innovation Program of Changzhou Campus,Hohai University,China(Grant No.17B01110)。
文摘A multicomponent thermal multi-relaxation-time(MRT)lattice Boltzmann method(LBM)is presented to study collapsing cavitation bubble.The simulation results satisfy Laplace law and the adiabatic law,and are consistent with the numerical solution of the Rayleigh-Plesset equation.To study the effects of the non-condensable gas inside bubble on collapsing cavitation bubble,a numerical model of single spherical bubble near a solid wall is established.The temperature and pressure evolution of the two-component two-phase flow are well captured.In addition,the collapse process of the cavitation bubble is discussed elaborately by setting the volume fractions of the gas and vapor to be the only variables.The results show that the non-condensable gas in the bubble significantly affects the pressure field,temperature field evolution,collapse velocity,and profile of the bubble.The distinction of the pressure and temperature on the wall after the second collapse becomes more obvious as the non-condensable gas concentration increases.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11874140,12064017,and 61765008)the Science and Technology Project of Changzhou,China(Grant Nos.CJ20210130,CJ20190046,and CJ20200073)the Postgraduate Research and Practice Innovation Program of Jiangsu Province,China(Grant Nos.B200203143 and KYCX200433)。
文摘According to the atmospheric pressure plasma(APP)technology,we propose a rapid synthetic approach of the substrates for enhanced Raman spectroscopy.The plasma is used to modify and etch the surface of silver film,which generates large scale hotspots'aggregation.By switching the discharge polarity and adjusting the film thickness,different surface morphologies are formed due to the oxidation,reactive etch and accumulation of the plasma product in a certain space.Especially under positive corona discharge condition,dense snake-like microstructures are formed by the gradual connection of individual nanoparticles,which are driven by the influence of the electric field on surface diffusion.In addition,the experiments verify that the corresponding enhancement factor(EF)raises at least five orders of magnitude and the treatment time is about 10 min.
