An iterative time-marching scheme is developed to investigate the hydrodynamic interactions between multiple ships.Such an unsteady interactive effect could be magnified in restricted waterways,e.g.,a channel or harbo...An iterative time-marching scheme is developed to investigate the hydrodynamic interactions between multiple ships.Such an unsteady interactive effect could be magnified in restricted waterways,e.g.,a channel or harbor area.To the author’s knowledge,nearly all the research on the ship-to-ship interaction neglecting the free surface effects.The free surface is usually treated as a rigid wall.This assumption is only reasonable when the speed of the ships is very low in deep water condition,due to the hydrodynamic interaction between the ships is mainly induced by near-field disturbances.However,when the moving speeds are moderately higher,especially with a small lateral separation between ships,the far-field effects arising from the ship waves become important.The main objective of the present paper is to develop an iterative time-matching algorithm to solve the hydrodynamic interaction between high-speed ships taking into account the nonlinear free surface boundary condition in time domain.展开更多
A time derivative preconditioning is introduced that allows a unified treatment of timemarching methods for both compressible and incompressible flows from inviscid to creeping flow. Results show that convergence rate...A time derivative preconditioning is introduced that allows a unified treatment of timemarching methods for both compressible and incompressible flows from inviscid to creeping flow. Results show that convergence rates are independent of Reynolds numbers and Mach numbers throughout this regime. A Complete formulation'based on an arbitrary equation of state facilitates the changes from one type of fluid to another and, in particular, the extension to incompressible flows. The resulting time-marching algorithm is shown in the incompressible limit to be identical to iterative methods based on pressure-Poisson methods, and it is demonstrated that both method are hyperbolic.展开更多
In this paper,two fully-discrete local discontinuous Galerkin(LDG)methods are applied to the growth-mediated autochemotactic pattern formation model in self-propelling bacteria.The numerical methods are linear and dec...In this paper,two fully-discrete local discontinuous Galerkin(LDG)methods are applied to the growth-mediated autochemotactic pattern formation model in self-propelling bacteria.The numerical methods are linear and decoupled,which greatly improve the computational efficiency.In order to resolve the time level mismatch of the discretization process,a special time marching method with high-order accuracy is constructed.Under the condition of slight time step constraints,the optimal error estimates of this method are given.Moreover,the theoretical results are verified by numerical experiments.Real simulations show the patterns of spots,rings,stripes as well as inverted spots because of the interplay of chemotactic drift and growth rate of the cells.展开更多
基金Projects supported by the National Natural Science Foundation of China(Grant No.51979131).
文摘An iterative time-marching scheme is developed to investigate the hydrodynamic interactions between multiple ships.Such an unsteady interactive effect could be magnified in restricted waterways,e.g.,a channel or harbor area.To the author’s knowledge,nearly all the research on the ship-to-ship interaction neglecting the free surface effects.The free surface is usually treated as a rigid wall.This assumption is only reasonable when the speed of the ships is very low in deep water condition,due to the hydrodynamic interaction between the ships is mainly induced by near-field disturbances.However,when the moving speeds are moderately higher,especially with a small lateral separation between ships,the far-field effects arising from the ship waves become important.The main objective of the present paper is to develop an iterative time-matching algorithm to solve the hydrodynamic interaction between high-speed ships taking into account the nonlinear free surface boundary condition in time domain.
文摘A time derivative preconditioning is introduced that allows a unified treatment of timemarching methods for both compressible and incompressible flows from inviscid to creeping flow. Results show that convergence rates are independent of Reynolds numbers and Mach numbers throughout this regime. A Complete formulation'based on an arbitrary equation of state facilitates the changes from one type of fluid to another and, in particular, the extension to incompressible flows. The resulting time-marching algorithm is shown in the incompressible limit to be identical to iterative methods based on pressure-Poisson methods, and it is demonstrated that both method are hyperbolic.
基金supported by National Natural Science Foundation of China(Grant No.11801569)Natural Science Foundation of Shandong Province(CN)(Grant No.ZR2021MA001)the Fundamental Research Funds for the Central Universities(Grant Nos.22CX03025A and 22CX03020A).
文摘In this paper,two fully-discrete local discontinuous Galerkin(LDG)methods are applied to the growth-mediated autochemotactic pattern formation model in self-propelling bacteria.The numerical methods are linear and decoupled,which greatly improve the computational efficiency.In order to resolve the time level mismatch of the discretization process,a special time marching method with high-order accuracy is constructed.Under the condition of slight time step constraints,the optimal error estimates of this method are given.Moreover,the theoretical results are verified by numerical experiments.Real simulations show the patterns of spots,rings,stripes as well as inverted spots because of the interplay of chemotactic drift and growth rate of the cells.
