A depth-integrated, non-hydrostatic model with hybrid finite difference and finite volume numerical algorithm is proposed in this paper. By utilizing a fraction step method, the governing equations are decomposed into...A depth-integrated, non-hydrostatic model with hybrid finite difference and finite volume numerical algorithm is proposed in this paper. By utilizing a fraction step method, the governing equations are decomposed into hydrostatic and non-hydrostatic parts. The first part is solved by using the finite volume conservative discretization method, whilst the latter is considered by solving discretized Poisson-type equations with the finite difference method. The second-order accuracy, both in time and space, of the finite volume scheme is achieved by using an explicit predictor-correction step and linear construction of variable state in cells. The fluxes across the cell faces are computed in a Godunov-based manner by using MUSTA scheme. Slope and flux limiting technique is used to equip the algorithm with total variation dimensioning property for shock capturing purpose. Wave breaking is treated as a shock by switching off the non-hydrostatic pressure in the steep wave front locally. The model deals with moving wet/dry front in a simple way. Numerical experiments are conducted to verify the proposed model.展开更多
This paper presents a study of pressure and velocity relaxation in twophase flow calculations.Several of the present observations have been made elsewhere,and the purpose of the paper is to strengthen these observatio...This paper presents a study of pressure and velocity relaxation in twophase flow calculations.Several of the present observations have been made elsewhere,and the purpose of the paper is to strengthen these observations and draw some conclusions.It is numerically demonstrated how a single-pressure two-fluid model is recovered when applying instantaneous pressure relaxation to a twopressure two-fluid model.Further,instantaneous velocity relaxation yields a driftflux model.It is also shown that the pressure relaxation has the disadvantage of inducing a large amount of numerical smearing.The comparisons have been conducted by using analogous numerical schemes,and a multi-stage centred(MUSTA)scheme for non-conservative two-fluid models has been applied to and tested on the two-pressure two-fluid model.As for other,previously tested two-phase flow models,the MUSTA schemes have been found to be robust,accurate and nonoscillatory.However,compared to their Roe reference schemes,they consistently have a lower computational efficiency for problems involving mass transport.展开更多
基金supported by the State Ocean Administration People’s Republic of China(Grant No.201405025)the Key Laboratory for Sea Area Management Technology(SOA)(Grant No.201603)
文摘A depth-integrated, non-hydrostatic model with hybrid finite difference and finite volume numerical algorithm is proposed in this paper. By utilizing a fraction step method, the governing equations are decomposed into hydrostatic and non-hydrostatic parts. The first part is solved by using the finite volume conservative discretization method, whilst the latter is considered by solving discretized Poisson-type equations with the finite difference method. The second-order accuracy, both in time and space, of the finite volume scheme is achieved by using an explicit predictor-correction step and linear construction of variable state in cells. The fluxes across the cell faces are computed in a Godunov-based manner by using MUSTA scheme. Slope and flux limiting technique is used to equip the algorithm with total variation dimensioning property for shock capturing purpose. Wave breaking is treated as a shock by switching off the non-hydrostatic pressure in the steep wave front locally. The model deals with moving wet/dry front in a simple way. Numerical experiments are conducted to verify the proposed model.
基金financed by SINTEF Energy Research and the Research Council of Norway.
文摘This paper presents a study of pressure and velocity relaxation in twophase flow calculations.Several of the present observations have been made elsewhere,and the purpose of the paper is to strengthen these observations and draw some conclusions.It is numerically demonstrated how a single-pressure two-fluid model is recovered when applying instantaneous pressure relaxation to a twopressure two-fluid model.Further,instantaneous velocity relaxation yields a driftflux model.It is also shown that the pressure relaxation has the disadvantage of inducing a large amount of numerical smearing.The comparisons have been conducted by using analogous numerical schemes,and a multi-stage centred(MUSTA)scheme for non-conservative two-fluid models has been applied to and tested on the two-pressure two-fluid model.As for other,previously tested two-phase flow models,the MUSTA schemes have been found to be robust,accurate and nonoscillatory.However,compared to their Roe reference schemes,they consistently have a lower computational efficiency for problems involving mass transport.
