Wave motions around different types of submerged structures are investigated by a numerical method, theboundary fitted coordinate method. The types of submerged structures include a submerged horizontal plate, submerg...Wave motions around different types of submerged structures are investigated by a numerical method, theboundary fitted coordinate method. The types of submerged structures include a submerged horizontal plate, submerged breakwaters (rectangular and trapezoidal) and a step-type structure (topography) . Water level fluctuations, wave height distributions, velocity fields and wave energies around submerged structures are studied comprehensively.展开更多
For most hierarchical triple stars, the classical double two-body model of zeroth-order cannot describe the motions of the components under the current observational accuracy. In this paper, Marchal＇s first-order ana...For most hierarchical triple stars, the classical double two-body model of zeroth-order cannot describe the motions of the components under the current observational accuracy. In this paper, Marchal＇s first-order analytical solution is implemented and a more efficient simplified version is applied to real triple stars. The results show that, for most triple stars, the proposed first-order model is preferable to the zerothorder model both in fitting observational data and in predicting component positions.展开更多
A set of nonlinear Boussinesq equations with fully nonlinearity property is solved numerically in generalized coordinates,to develop a Boussinesq-type wave model in dealing with irregular computation boundaries in com...A set of nonlinear Boussinesq equations with fully nonlinearity property is solved numerically in generalized coordinates,to develop a Boussinesq-type wave model in dealing with irregular computation boundaries in complex nearshore regions and to facilitate the grid refinements in simulations.The governing equations expressed in contravariant components of velocity vectors under curvilinear coordinates are derived and a high order finite difference scheme on a staggered grid is employed for the numerical implementation.The developed model is used to simulate nearshore wave propagations under curvilinear coordinates,the numerical results are compared against analytical or experimental data with a good agreement.展开更多
In this paper,a modified boundary fitted coordinate method is presented.The transformation equations are solved by finite analytic method.The control equations after trans- formation are solved by splitting operator m...In this paper,a modified boundary fitted coordinate method is presented.The transformation equations are solved by finite analytic method.The control equations after trans- formation are solved by splitting operator method.The results of calculation consist well with experiments.展开更多
In the present study, a new algorithm based on the Volume Of Fluid （VOF） method is developed to simulate the hydrodynamic characteristics on an arc crown wall. Structured grids are generated by the coordinate transf...In the present study, a new algorithm based on the Volume Of Fluid （VOF） method is developed to simulate the hydrodynamic characteristics on an arc crown wall. Structured grids are generated by the coordinate transform method in an arbitrary complex region. The Navier-Stokes equations for two-dimensional incompressible viscous flows are discretized in the Body Fitted Coordinate （BFC） system. The transformed SIMPLE algorithm is proposed to modify the pressure-velocity field and a transformed VOF method is used to trace the free surface. Hydrodynamic characteristics on an arc crown wall are obtained by the improved numerical model based on the BFC system （BFC model）. The velocity field, the pressure field and the time profiles of the water surface near the arc crown wall obtained by using the BFC model and the Cartesian model are compared. The BFC model is verified by experimental results.展开更多
WT5”BZ]A numerical method, the boundary fitted coordinate method (BFC), was used to investigate the transmission and reflection of water waves due to a rigid thin vertical barrier descending from the water surface to...WT5”BZ]A numerical method, the boundary fitted coordinate method (BFC), was used to investigate the transmission and reflection of water waves due to a rigid thin vertical barrier descending from the water surface to a depth, i.e., a curtain-wall type breakwater. A comparison between the present computed results and previous experimental and analytical results was carried out which verifies the prediction of the BFC method. Wave transmission and reflection due to the barrier were computed, and the transmission and refiection coefficients were given in a figure. [WT5”HZ]展开更多
This paper is conserned with a numerical method for the solution of complete Reynolds averaged Navier Stokes equations for three dimensional flows over the concave surfaces of discharging structures. A non orthogo...This paper is conserned with a numerical method for the solution of complete Reynolds averaged Navier Stokes equations for three dimensional flows over the concave surfaces of discharging structures. A non orthogonal body fitted coordinate system was used to deal with the complex physical geometry, and finite volume method (FVM) was employed to solve the convective transport equations for mean velocities and turbulence parameters (k, ε). It is indicated through the numerical example that the calculated results are in good agreement with the experimental ones, and it is also proved that this numerical method used to predict the characteristics of turbulent flow over the concave surfaces of discharging structures is feasible.展开更多
文摘Wave motions around different types of submerged structures are investigated by a numerical method, theboundary fitted coordinate method. The types of submerged structures include a submerged horizontal plate, submerged breakwaters (rectangular and trapezoidal) and a step-type structure (topography) . Water level fluctuations, wave height distributions, velocity fields and wave energies around submerged structures are studied comprehensively.
基金supported by the National Natural Science Foundation of China under Grant Nos. 11178006 and 11203086
文摘For most hierarchical triple stars, the classical double two-body model of zeroth-order cannot describe the motions of the components under the current observational accuracy. In this paper, Marchal＇s first-order analytical solution is implemented and a more efficient simplified version is applied to real triple stars. The results show that, for most triple stars, the proposed first-order model is preferable to the zerothorder model both in fitting observational data and in predicting component positions.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.51009018,51079024)the Founds for Creative Research Groups of China (Grant No.50921001)+1 种基金the Key Laboratory of Coastal Disaster and Defence,Ministry of Education,Hohai University (Grant No.200803)the State Key Laboratory of Coastal and Offshore Engineering,Dalian University of Technology (Grant No.LP1105)
文摘A set of nonlinear Boussinesq equations with fully nonlinearity property is solved numerically in generalized coordinates,to develop a Boussinesq-type wave model in dealing with irregular computation boundaries in complex nearshore regions and to facilitate the grid refinements in simulations.The governing equations expressed in contravariant components of velocity vectors under curvilinear coordinates are derived and a high order finite difference scheme on a staggered grid is employed for the numerical implementation.The developed model is used to simulate nearshore wave propagations under curvilinear coordinates,the numerical results are compared against analytical or experimental data with a good agreement.
文摘In this paper,a modified boundary fitted coordinate method is presented.The transformation equations are solved by finite analytic method.The control equations after trans- formation are solved by splitting operator method.The results of calculation consist well with experiments.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51179030, 50921001)
文摘In the present study, a new algorithm based on the Volume Of Fluid （VOF） method is developed to simulate the hydrodynamic characteristics on an arc crown wall. Structured grids are generated by the coordinate transform method in an arbitrary complex region. The Navier-Stokes equations for two-dimensional incompressible viscous flows are discretized in the Body Fitted Coordinate （BFC） system. The transformed SIMPLE algorithm is proposed to modify the pressure-velocity field and a transformed VOF method is used to trace the free surface. Hydrodynamic characteristics on an arc crown wall are obtained by the improved numerical model based on the BFC system （BFC model）. The velocity field, the pressure field and the time profiles of the water surface near the arc crown wall obtained by using the BFC model and the Cartesian model are compared. The BFC model is verified by experimental results.
文摘WT5”BZ]A numerical method, the boundary fitted coordinate method (BFC), was used to investigate the transmission and reflection of water waves due to a rigid thin vertical barrier descending from the water surface to a depth, i.e., a curtain-wall type breakwater. A comparison between the present computed results and previous experimental and analytical results was carried out which verifies the prediction of the BFC method. Wave transmission and reflection due to the barrier were computed, and the transmission and refiection coefficients were given in a figure. [WT5”HZ]
基金The work was supported by the 95'Natlonal Scientific Research Project.(No.95-221-05-01)
文摘This paper is conserned with a numerical method for the solution of complete Reynolds averaged Navier Stokes equations for three dimensional flows over the concave surfaces of discharging structures. A non orthogonal body fitted coordinate system was used to deal with the complex physical geometry, and finite volume method (FVM) was employed to solve the convective transport equations for mean velocities and turbulence parameters (k, ε). It is indicated through the numerical example that the calculated results are in good agreement with the experimental ones, and it is also proved that this numerical method used to predict the characteristics of turbulent flow over the concave surfaces of discharging structures is feasible.
