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
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
In this paper a finite volume method for solving inverse problem of transonic viscousflow is preseflted. The method is based on a timermarching finite volume method and apressure residual correction formula. The resid...In this paper a finite volume method for solving inverse problem of transonic viscousflow is preseflted. The method is based on a timermarching finite volume method and apressure residual correction formula. The residual correction formula is an auxiliary partialdifferelltial equation that is solved for incremental changes in surface coordinates duringeach computational cycle. In the paper a transonic turbine cascade was calculated anddemonstrated. The inverse solution was agreed with the target well.展开更多
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In this paper a finite volume method for solving inverse problem of transonic viscousflow is preseflted. The method is based on a timermarching finite volume method and apressure residual correction formula. The residual correction formula is an auxiliary partialdifferelltial equation that is solved for incremental changes in surface coordinates duringeach computational cycle. In the paper a transonic turbine cascade was calculated anddemonstrated. The inverse solution was agreed with the target well.
