An improved algorithm for computing multiphase flows is presented in which the multimaterial Moment-of-Fluid(MOF)algorithm for multiphase flows,initially described by Li et al.(2015),is enhanced addressing existing MO...An improved algorithm for computing multiphase flows is presented in which the multimaterial Moment-of-Fluid(MOF)algorithm for multiphase flows,initially described by Li et al.(2015),is enhanced addressing existing MOF difficulties in computing solutions to problems in which surface tension forces are crucial for understanding salient flow mechanisms.The Continuous MOF(CMOF)method is motivated in this article.The CMOF reconstruction method inherently removes the"checkerboard instability"that persists when using the MOF method on surface tension driven multiphase(multimaterial)flows.The CMOF reconstruction algorithm is accelerated by coupling the CMOF method to the level set method and coupling the CMOF method to a decision tree machine learning(ML)algorithm.Multiphase flow examples are shown in the two-dimensional(2D),three-dimensional(3D)axisymmetric"RZ",and 3D coordinate systems.Examples include two material and three material multiphase flows:bubble formation,the impingement of a liquid jet on a gas bubble in a cryogenic fuel tank,freezing,and liquid lens dynamics.展开更多
Liquid metal droplets are accelerated by electrostatic forces in a process known as field emission.In this study,we simulate the emission of charged indium droplets on a needle in 2D cylindrical coordinates.The bounda...Liquid metal droplets are accelerated by electrostatic forces in a process known as field emission.In this study,we simulate the emission of charged indium droplets on a needle in 2D cylindrical coordinates.The boundary element method is used to rapidly and accurately calculate the electric field on the fluid surface,which is then advected forward in time using level sets.This is the first time these methods have been combined,and this combination addresses difficult detachable surface tracking issues successfully.A histogram of droplet charge-to-mass ratio is generated in which it is predicted that smaller satellite droplets are more densely charged.In addition,our model is compared with independent pre-and post-snap off data and produces good agreement with the result.展开更多
基金supported by the National Aeronautics and Space Administration under grant number 80NSSC20K0352.
文摘An improved algorithm for computing multiphase flows is presented in which the multimaterial Moment-of-Fluid(MOF)algorithm for multiphase flows,initially described by Li et al.(2015),is enhanced addressing existing MOF difficulties in computing solutions to problems in which surface tension forces are crucial for understanding salient flow mechanisms.The Continuous MOF(CMOF)method is motivated in this article.The CMOF reconstruction method inherently removes the"checkerboard instability"that persists when using the MOF method on surface tension driven multiphase(multimaterial)flows.The CMOF reconstruction algorithm is accelerated by coupling the CMOF method to the level set method and coupling the CMOF method to a decision tree machine learning(ML)algorithm.Multiphase flow examples are shown in the two-dimensional(2D),three-dimensional(3D)axisymmetric"RZ",and 3D coordinate systems.Examples include two material and three material multiphase flows:bubble formation,the impingement of a liquid jet on a gas bubble in a cryogenic fuel tank,freezing,and liquid lens dynamics.
基金supported in part by the NSF under contract DMS 0108672Christlieb’s work supported in part by the Air Force Office of Scientific Research(AFOSR)under Grant FA9550-05-1-0199.
文摘Liquid metal droplets are accelerated by electrostatic forces in a process known as field emission.In this study,we simulate the emission of charged indium droplets on a needle in 2D cylindrical coordinates.The boundary element method is used to rapidly and accurately calculate the electric field on the fluid surface,which is then advected forward in time using level sets.This is the first time these methods have been combined,and this combination addresses difficult detachable surface tracking issues successfully.A histogram of droplet charge-to-mass ratio is generated in which it is predicted that smaller satellite droplets are more densely charged.In addition,our model is compared with independent pre-and post-snap off data and produces good agreement with the result.
