.In this paper,an augmented Lagrangian Uzawa iterative method is developed and analyzed for solving a class of double saddle-point systems with semidefinite(2,2)block.Convergence of the iterativemethod is proved under....In this paper,an augmented Lagrangian Uzawa iterative method is developed and analyzed for solving a class of double saddle-point systems with semidefinite(2,2)block.Convergence of the iterativemethod is proved under the assumption that the double saddle-point problem exists a unique solution.An application of the iterative method to the double saddle-point systems arising from the distributed Lagrange multiplier/fictitious domain(DLM/FD)finite element method for solving elliptic interface problems is also presented,in which the existence and uniqueness of the double saddle-point system is guaranteed by the analysis of the DLM/FD finite element method.Numerical experiments are conducted to validate the theoretical results and to study the performance of the proposed iterative method.展开更多
Distributed Lagrange Multiplier/Fictitious Domain （DLM/FD） method was employed to simulate the channel flow with polymer suspension. The polymer molecules were modeled as Finitely Extensible Nonlinear Elastic （FENE...Distributed Lagrange Multiplier/Fictitious Domain （DLM/FD） method was employed to simulate the channel flow with polymer suspension. The polymer molecules were modeled as Finitely Extensible Nonlinear Elastic （FENE） chains and FENE chain cluster. The coiled stretched transition of FENE chains was examined and the change in configuration of FENE chains was presented. The average velocity profile of the fully developed channel flow with 64 FENE chains was given and fitted well with the power-law curve. The change of chain cluster configuration was also simulated. These simulations show that DLM/FD method is capable of simulating the motion of not only FENE chain, but also FENE chain cluster.展开更多
The sedimentation of circular particles in a vertical channel filled withOldroyd ― B fluid was studied by an improved Distributed Lagrange Multiplier/fictitious domain(DLM) method. The sedimenting behaviors of two pa...The sedimentation of circular particles in a vertical channel filled withOldroyd ― B fluid was studied by an improved Distributed Lagrange Multiplier/fictitious domain(DLM) method. The sedimenting behaviors of two particles are presented firstly, which shows that,when the particles are dropped in a viscoealstic fluid, the stable configuration is the one wherethe particles are aligned parallel to the flow direction when the Mach number Mis less than 1 andthe elasticity number E is greater than 1. This agrees well with the known experimental in Ref. [1]and simulation results in Ref. [2]. Our simulations also show that, as in Newtonian fluid, thesedimentation of the particles will be accelerated due to the .interaction between particles in aviscoealstic fluid.展开更多
基金supported by the 10 plus 10 project of Tongji University(No.4260141304/004/010).
文摘.In this paper,an augmented Lagrangian Uzawa iterative method is developed and analyzed for solving a class of double saddle-point systems with semidefinite(2,2)block.Convergence of the iterativemethod is proved under the assumption that the double saddle-point problem exists a unique solution.An application of the iterative method to the double saddle-point systems arising from the distributed Lagrange multiplier/fictitious domain(DLM/FD)finite element method for solving elliptic interface problems is also presented,in which the existence and uniqueness of the double saddle-point system is guaranteed by the analysis of the DLM/FD finite element method.Numerical experiments are conducted to validate the theoretical results and to study the performance of the proposed iterative method.
文摘Distributed Lagrange Multiplier/Fictitious Domain （DLM/FD） method was employed to simulate the channel flow with polymer suspension. The polymer molecules were modeled as Finitely Extensible Nonlinear Elastic （FENE） chains and FENE chain cluster. The coiled stretched transition of FENE chains was examined and the change in configuration of FENE chains was presented. The average velocity profile of the fully developed channel flow with 64 FENE chains was given and fitted well with the power-law curve. The change of chain cluster configuration was also simulated. These simulations show that DLM/FD method is capable of simulating the motion of not only FENE chain, but also FENE chain cluster.
文摘The sedimentation of circular particles in a vertical channel filled withOldroyd ― B fluid was studied by an improved Distributed Lagrange Multiplier/fictitious domain(DLM) method. The sedimenting behaviors of two particles are presented firstly, which shows that,when the particles are dropped in a viscoealstic fluid, the stable configuration is the one wherethe particles are aligned parallel to the flow direction when the Mach number Mis less than 1 andthe elasticity number E is greater than 1. This agrees well with the known experimental in Ref. [1]and simulation results in Ref. [2]. Our simulations also show that, as in Newtonian fluid, thesedimentation of the particles will be accelerated due to the .interaction between particles in aviscoealstic fluid.
