In the previous studies,the phenomenon that the interstitial fluid(ISF)can flow along tunica adventitia of the arteries and veins in both human and animal bodies was reported.On the basis of these studies,this paper a...In the previous studies,the phenomenon that the interstitial fluid(ISF)can flow along tunica adventitia of the arteries and veins in both human and animal bodies was reported.On the basis of these studies,this paper aims to:(i)summarize the basic properties of the ISF flows in the walls of arteries and veins,(ii)combine the basic properties with axiomaticism and abstract the axiom for ISF flows,and(iii)propose three fundamental laws of the ISF flow,(i.e.,the existence law,the homotropic law and the reverse law).The three laws provide solid theoretical basement for exploring the kinematic patterns of interstitial fluid flow in the cardiovascular system.展开更多
The interaction length induced by Shock Wave/Turbulent Boundary-Layer Interactions(SWTBLIs)in the hypersonic flow was investigated using a scaling analysis,in which the interaction length normalized by the displacemen...The interaction length induced by Shock Wave/Turbulent Boundary-Layer Interactions(SWTBLIs)in the hypersonic flow was investigated using a scaling analysis,in which the interaction length normalized by the displacement thickness of boundary layer was correlated with a corrected non-dimensional separation criterion across the interaction after accounting for the wall temperature effects.A large number of hypersonic SWTBLIs were compiled to examine the scaling analysis over a wide range of Mach numbers,Reynolds numbers,and wall temperatures.The results indicate that the hypersonic SWTBLIs with low Reynolds numbers collapse on the supersonic SWTBLIs,while the hypersonic cases with high Reynolds numbers show a more rapid growth of the interaction length than that with low Reynolds numbers.Thus,two scaling relationships are identified according to different Reynolds numbers for the hypersonic SWTBLIs.The scaling analysis provides valuable guidelines for engineering prediction of the interaction length,and thus,enriches the knowledge of hypersonic SWTBLIs.展开更多
In this paper I review three key topics in CFD that have kept researchers busy for half a century.First,the concept of upwind differencing,evident for 1-D linear advection.Second,its implementation for nonlinear syste...In this paper I review three key topics in CFD that have kept researchers busy for half a century.First,the concept of upwind differencing,evident for 1-D linear advection.Second,its implementation for nonlinear systems in the form of highresolution schemes,now regarded as classical.Third,its genuinely multidimensional implementation in the form of residual-distribution schemes,the most recent addition.This lecture focuses on historical developments;it is not intended as a technical review of methods,hence the lack of formulas and absence of figures.展开更多
In this paper, we present a technique to redistribute car flows, described by a fluid dynamic model, on a portion of the Caltanissetta city, in Italy, when critical situations, such as car accidents, occur. Using a de...In this paper, we present a technique to redistribute car flows, described by a fluid dynamic model, on a portion of the Caltanissetta city, in Italy, when critical situations, such as car accidents, occur. Using a decentralized approach, a cost functional, that describes the asymptotic average velocity of emergency vehicles, is maximized with respect to distribution coefficients at simple junctions with two incoming roads and two outgoing ones. Then, in order to manage critical situations in high traffic conditions, local optimal coefficients at each node of the network are used. The overall traffic evolution is studied via simulations, that confirm the goodness of the optimization results. It is also proved that optimal coefficients allow a fast transit of emergency vehicles on assigned routes on the network.展开更多
For compressible multiphase flow models the proper definition of averages of nonlinear terms is an essential problem which is called the closure problem. The purpose of the present work is to verify the spatial homoge...For compressible multiphase flow models the proper definition of averages of nonlinear terms is an essential problem which is called the closure problem. The purpose of the present work is to verify the spatial homogeneity closure, based on analysis of the simulation data. Various proposed closures are compared in a verification study to spatial averages of numerical simulations.展开更多
Under investigation in this paper is a hyperbolic mean curvature flow for convex evolving curves.Firstly,in view of Lie group analysis,infinitesimal generators,symmetry groups and an optimal system of symmetries of th...Under investigation in this paper is a hyperbolic mean curvature flow for convex evolving curves.Firstly,in view of Lie group analysis,infinitesimal generators,symmetry groups and an optimal system of symmetries of the considered hyperbolic mean curvature flow are presented.At the same time,some group invariant solutions are computed through reduced equations.In particular,we construct explicit solutions by applying the power series method.Furthermore,the convergence of the solutions of power series is certificated.Finally,conservation laws of the hyperbolic mean curvature flow are established via Ibragimov's approach.展开更多
基金This work was financially supported by the National Natural Science Foundation of China(Grants 12050001,82050004,and 11672150).
文摘In the previous studies,the phenomenon that the interstitial fluid(ISF)can flow along tunica adventitia of the arteries and veins in both human and animal bodies was reported.On the basis of these studies,this paper aims to:(i)summarize the basic properties of the ISF flows in the walls of arteries and veins,(ii)combine the basic properties with axiomaticism and abstract the axiom for ISF flows,and(iii)propose three fundamental laws of the ISF flow,(i.e.,the existence law,the homotropic law and the reverse law).The three laws provide solid theoretical basement for exploring the kinematic patterns of interstitial fluid flow in the cardiovascular system.
基金supported by the National Natural Science Foundation of China(Nos.11772325 and 11621202)。
文摘The interaction length induced by Shock Wave/Turbulent Boundary-Layer Interactions(SWTBLIs)in the hypersonic flow was investigated using a scaling analysis,in which the interaction length normalized by the displacement thickness of boundary layer was correlated with a corrected non-dimensional separation criterion across the interaction after accounting for the wall temperature effects.A large number of hypersonic SWTBLIs were compiled to examine the scaling analysis over a wide range of Mach numbers,Reynolds numbers,and wall temperatures.The results indicate that the hypersonic SWTBLIs with low Reynolds numbers collapse on the supersonic SWTBLIs,while the hypersonic cases with high Reynolds numbers show a more rapid growth of the interaction length than that with low Reynolds numbers.Thus,two scaling relationships are identified according to different Reynolds numbers for the hypersonic SWTBLIs.The scaling analysis provides valuable guidelines for engineering prediction of the interaction length,and thus,enriches the knowledge of hypersonic SWTBLIs.
文摘In this paper I review three key topics in CFD that have kept researchers busy for half a century.First,the concept of upwind differencing,evident for 1-D linear advection.Second,its implementation for nonlinear systems in the form of highresolution schemes,now regarded as classical.Third,its genuinely multidimensional implementation in the form of residual-distribution schemes,the most recent addition.This lecture focuses on historical developments;it is not intended as a technical review of methods,hence the lack of formulas and absence of figures.
文摘In this paper, we present a technique to redistribute car flows, described by a fluid dynamic model, on a portion of the Caltanissetta city, in Italy, when critical situations, such as car accidents, occur. Using a decentralized approach, a cost functional, that describes the asymptotic average velocity of emergency vehicles, is maximized with respect to distribution coefficients at simple junctions with two incoming roads and two outgoing ones. Then, in order to manage critical situations in high traffic conditions, local optimal coefficients at each node of the network are used. The overall traffic evolution is studied via simulations, that confirm the goodness of the optimization results. It is also proved that optimal coefficients allow a fast transit of emergency vehicles on assigned routes on the network.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education,Science and Technology(No.NRF-2009-0069783)
文摘For compressible multiphase flow models the proper definition of averages of nonlinear terms is an essential problem which is called the closure problem. The purpose of the present work is to verify the spatial homogeneity closure, based on analysis of the simulation data. Various proposed closures are compared in a verification study to spatial averages of numerical simulations.
基金Supported by the Natural Science Foundation of Shanxi(202103021224068).
文摘Under investigation in this paper is a hyperbolic mean curvature flow for convex evolving curves.Firstly,in view of Lie group analysis,infinitesimal generators,symmetry groups and an optimal system of symmetries of the considered hyperbolic mean curvature flow are presented.At the same time,some group invariant solutions are computed through reduced equations.In particular,we construct explicit solutions by applying the power series method.Furthermore,the convergence of the solutions of power series is certificated.Finally,conservation laws of the hyperbolic mean curvature flow are established via Ibragimov's approach.
