Recent years the modify ghost fluid method （MGFM） and the real ghost fluid method （RGFM） based on Riemann problem have been developed for multimedium compressible flows. According to authors, these methods have on...Recent years the modify ghost fluid method （MGFM） and the real ghost fluid method （RGFM） based on Riemann problem have been developed for multimedium compressible flows. According to authors, these methods have only been used with the level set technique to track the interface. In this paper, we combine the MCFM and the RGFM respectively with front tracking method, for which the fluid interfaces are explicitly tracked by connected points. The method is tested with some one-dimensional problems, and its applicability is also studied. Furthermore, in order to capture the interface more accurately, especially for strong shock impacting on interface, a shock monitor is proposed to determine the initial states of the Riemann problem. The present method is applied to various one- dimensional problems involving strong shock-interface interaction. An extension of the present method to two dimension is also introduced and preliminary results are given.展开更多
In this paper,we extend using the Runge-Kutta discontinuous Galerkin method together with the front tracking method to simulate the compressible twomedium flow on unstructured meshes.A Riemann problem is constructed i...In this paper,we extend using the Runge-Kutta discontinuous Galerkin method together with the front tracking method to simulate the compressible twomedium flow on unstructured meshes.A Riemann problem is constructed in the normal direction in the material interfacial region,with the goal of obtaining a compact,robust and efficient procedure to track the explicit sharp interface precisely.Extensive numerical tests including the gas-gas and gas-liquid flows are provided to show the proposed methodologies possess the capability of enhancing the resolutions nearby the discontinuities inside of the single medium flow and the interfacial vicinities of the two-medium flow in many occasions.展开更多
A front trackingmethod combinedwith the real ghost fluidmethod(RGFM)is proposed for simulations of fluid interfaces in two-dimensional compressible flows.In this paper the Riemann problem is constructed along the norm...A front trackingmethod combinedwith the real ghost fluidmethod(RGFM)is proposed for simulations of fluid interfaces in two-dimensional compressible flows.In this paper the Riemann problem is constructed along the normal direction of interface and the corresponding Riemann solutions are used to track fluid interfaces.The interface boundary conditions are defined by the RGFM,and the fluid interfaces are explicitly tracked by several connected marker points.The Riemann solutions are also used directly to update the flow states on both sides of the interface in the RGFM.In order to validate the accuracy and capacity of the new method,extensive numerical tests including the bubble advection,the Sod tube,the shock-bubble interaction,the Richtmyer-Meshkov instability and the gas-water interface,are simulated by using the Euler equations.The computational results are also compared with earlier computational studies and it shows good agreements including the compressible gas-water system with large density differences.展开更多
The ghost fluid method(GFM)provides a simple way to simulate the interaction of immiscible materials.Especially,the modified GFM(MGFM)and its variants,based on the solutions of multi-material Riemann problems,are capa...The ghost fluid method(GFM)provides a simple way to simulate the interaction of immiscible materials.Especially,the modified GFM(MGFM)and its variants,based on the solutions of multi-material Riemann problems,are capable of faithfully taking into account the effects of nonlinear wave interaction and material property near the interface.Reasonable treatments for ghost fluid states or interface conditions have been shown to be crucial when applied to various interfacial phenomena involving large discontinuity and strong nonlinearity.These methods,therefore,have great potential in engineering applications.In this paper,we review the development of such methods.The methodologies of representative GFM-based algorithms for definition of interface conditions are illustrated and compared to each other.The research progresses in design principle and accuracy analysis are briefly described.Some steps and techniques for multi-dimensional extension are also summarized.In addition,we present some progresses in more challenging scientific problems,including a variety of fluid/solid-fluid/solid interactions with complex physical properties.Of course the challenges faced by researchers in this field are also discussed.展开更多
基金supported by National Science Foundation of China (10576015)
文摘Recent years the modify ghost fluid method （MGFM） and the real ghost fluid method （RGFM） based on Riemann problem have been developed for multimedium compressible flows. According to authors, these methods have only been used with the level set technique to track the interface. In this paper, we combine the MCFM and the RGFM respectively with front tracking method, for which the fluid interfaces are explicitly tracked by connected points. The method is tested with some one-dimensional problems, and its applicability is also studied. Furthermore, in order to capture the interface more accurately, especially for strong shock impacting on interface, a shock monitor is proposed to determine the initial states of the Riemann problem. The present method is applied to various one- dimensional problems involving strong shock-interface interaction. An extension of the present method to two dimension is also introduced and preliminary results are given.
基金The research was supported by the National Basic Research Program of China(”973”Program)under grant No.2014CB046200NSFC grants 11432007,11372005,11271188Additional support is provided by a project funded by the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions。
文摘In this paper,we extend using the Runge-Kutta discontinuous Galerkin method together with the front tracking method to simulate the compressible twomedium flow on unstructured meshes.A Riemann problem is constructed in the normal direction in the material interfacial region,with the goal of obtaining a compact,robust and efficient procedure to track the explicit sharp interface precisely.Extensive numerical tests including the gas-gas and gas-liquid flows are provided to show the proposed methodologies possess the capability of enhancing the resolutions nearby the discontinuities inside of the single medium flow and the interfacial vicinities of the two-medium flow in many occasions.
基金All the authors are supported by NSFC grants 91130030 and 11432007Additional support is provided by a project funded by the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions.The authors would like to thank Pro-fessor Jie Wu for his useful suggestions.
文摘A front trackingmethod combinedwith the real ghost fluidmethod(RGFM)is proposed for simulations of fluid interfaces in two-dimensional compressible flows.In this paper the Riemann problem is constructed along the normal direction of interface and the corresponding Riemann solutions are used to track fluid interfaces.The interface boundary conditions are defined by the RGFM,and the fluid interfaces are explicitly tracked by several connected marker points.The Riemann solutions are also used directly to update the flow states on both sides of the interface in the RGFM.In order to validate the accuracy and capacity of the new method,extensive numerical tests including the bubble advection,the Sod tube,the shock-bubble interaction,the Richtmyer-Meshkov instability and the gas-water interface,are simulated by using the Euler equations.The computational results are also compared with earlier computational studies and it shows good agreements including the compressible gas-water system with large density differences.
基金supported under the National Natural Science Foundation of China(Nos.11872351 and U1730118)Science Challenge Project(No.JCKY2016212A502).
文摘The ghost fluid method(GFM)provides a simple way to simulate the interaction of immiscible materials.Especially,the modified GFM(MGFM)and its variants,based on the solutions of multi-material Riemann problems,are capable of faithfully taking into account the effects of nonlinear wave interaction and material property near the interface.Reasonable treatments for ghost fluid states or interface conditions have been shown to be crucial when applied to various interfacial phenomena involving large discontinuity and strong nonlinearity.These methods,therefore,have great potential in engineering applications.In this paper,we review the development of such methods.The methodologies of representative GFM-based algorithms for definition of interface conditions are illustrated and compared to each other.The research progresses in design principle and accuracy analysis are briefly described.Some steps and techniques for multi-dimensional extension are also summarized.In addition,we present some progresses in more challenging scientific problems,including a variety of fluid/solid-fluid/solid interactions with complex physical properties.Of course the challenges faced by researchers in this field are also discussed.
