Three dimensional Euler equations are solved in the finite volume form with van Leer's flux vector splitting technique. Block matrix is inverted by Gauss-Seidel iteration in two dimensional plane while strongly im...Three dimensional Euler equations are solved in the finite volume form with van Leer's flux vector splitting technique. Block matrix is inverted by Gauss-Seidel iteration in two dimensional plane while strongly implicit alternating sweeping is implemented in the direction of the third dimension. Very rapid convergence rate is obtained with CFL number reaching the order of 100. The memory resources can be greatly saved too. It is verified that the reflection boundary condition can not be used with flux vector splitting since it will produce too large numerical dissipation. The computed flow fields agree well with experimental results. Only one or two grid points are there within the shock transition zone.展开更多
The calculated methods of the compositional dependence of the energy bandgap for Ga_xIn_(1-x)As_(1-y)Sb_y quaternary alloys are discussed in this paper. The dielectric theory of electronegativity and the linearinterpo...The calculated methods of the compositional dependence of the energy bandgap for Ga_xIn_(1-x)As_(1-y)Sb_y quaternary alloys are discussed in this paper. The dielectric theory of electronegativity and the linearinterpolation method were respectively used to calculate the compositional dependence of the energybandgap for Ca_xIn_(1-x)As_(1-y)Sb_y quaternary alloys. The same formula was deduced from the two schemes.According to the two formulas, we calculate the energy handgap as a function of alloy compositions forGa_xIn_(1-x)As_(1-y)Sb_y quaternary alloys: moreover, the temperature effect was lead into the formulas. Com-paring the calculated values with the measured ones, we found that the calculated method is in good agree-ment with the experimental data for Ga_xIn_(1-x)As_(1-y_Sb_y quaternary alloys.展开更多
In first paper of articles, the physical and calculating schemes of the water-bearing numerical model are described. The model is developed by bearing all species of hydrometeors in a conventional numerical model in ...In first paper of articles, the physical and calculating schemes of the water-bearing numerical model are described. The model is developed by bearing all species of hydrometeors in a conventional numerical model in which the dynamic framework of hydrostatic equilibrium is taken. The main contributions are: the mixing ratios of all species of hydrometeors are added as the prognostic variables of model, the prognostic equations of these hydrometeors are introduced, the cloud physical framework is specially designed, some technical measures are used to resolve a series of physical, mathematical and computational problems arising from water-bearing; and so on. The various problems (in such aspects as the designs of physical and calculating schemes and the composition of computational programme) which are exposed in feasibility test, in sensibility test, and especially in operational forecasting experiments are successfully resolved using a lot of technical measures having been developed from researches and tests. Finally, the operational forecasting running of the water-bearing numerical model and its forecasting system is realized stably and reliably, and the fine forecasts are obtained. All of these mentioned above will be described in second paper.展开更多
文摘Three dimensional Euler equations are solved in the finite volume form with van Leer's flux vector splitting technique. Block matrix is inverted by Gauss-Seidel iteration in two dimensional plane while strongly implicit alternating sweeping is implemented in the direction of the third dimension. Very rapid convergence rate is obtained with CFL number reaching the order of 100. The memory resources can be greatly saved too. It is verified that the reflection boundary condition can not be used with flux vector splitting since it will produce too large numerical dissipation. The computed flow fields agree well with experimental results. Only one or two grid points are there within the shock transition zone.
文摘The calculated methods of the compositional dependence of the energy bandgap for Ga_xIn_(1-x)As_(1-y)Sb_y quaternary alloys are discussed in this paper. The dielectric theory of electronegativity and the linearinterpolation method were respectively used to calculate the compositional dependence of the energybandgap for Ca_xIn_(1-x)As_(1-y)Sb_y quaternary alloys. The same formula was deduced from the two schemes.According to the two formulas, we calculate the energy handgap as a function of alloy compositions forGa_xIn_(1-x)As_(1-y)Sb_y quaternary alloys: moreover, the temperature effect was lead into the formulas. Com-paring the calculated values with the measured ones, we found that the calculated method is in good agree-ment with the experimental data for Ga_xIn_(1-x)As_(1-y_Sb_y quaternary alloys.
文摘In first paper of articles, the physical and calculating schemes of the water-bearing numerical model are described. The model is developed by bearing all species of hydrometeors in a conventional numerical model in which the dynamic framework of hydrostatic equilibrium is taken. The main contributions are: the mixing ratios of all species of hydrometeors are added as the prognostic variables of model, the prognostic equations of these hydrometeors are introduced, the cloud physical framework is specially designed, some technical measures are used to resolve a series of physical, mathematical and computational problems arising from water-bearing; and so on. The various problems (in such aspects as the designs of physical and calculating schemes and the composition of computational programme) which are exposed in feasibility test, in sensibility test, and especially in operational forecasting experiments are successfully resolved using a lot of technical measures having been developed from researches and tests. Finally, the operational forecasting running of the water-bearing numerical model and its forecasting system is realized stably and reliably, and the fine forecasts are obtained. All of these mentioned above will be described in second paper.
