central difference
1.using Yee’s central differencing in time and space, the Maxwell’s equation can be written central difference form, then polarization P, dielectric field E and magnetic field H can be calculated.
2.Sets up three-dimensional movement modal of towed-cable, the vector dynamic equilibrium equation is expanded under local coordinate, and numerically discreted by central difference on time and space through transforming Eular angle.
3.The in viscid flux is discretized by AUSM+ scheme. The viscid flux is discretized by second-order central difference scheme. Baldwin-Lomax turbulence model is implemented in Navier-Stokes flow solver.
4.Because it could not measure wave disturbance of real system, but we could easy get ship motion attitude and use the dependence of measuring state variable to estimate wave disturbance by means of three methods: central difference, Kalman filtering and extended Kalman filtering.
5.Based on central difference scheme, explicit upwind scheme, Samarskii scheme and modified Dennis scheme, some new alternating group explicit methods and alternating direction explicit methods are constructed for solving convection diffusion equation. Their experimental model and results of numerical comparison are given.
6.LU-SGS implicit iterative method and JST central difference scheme are used to solve the two-dimensional Navier-Stokes equations with dual time step . The results of the numerical simulation carried on the viscous lid-driven cavity flow show that the dual time method used here can be applied to solve unsteady flows.
7.Based on time-domain beam propagation methods (TD-BPM) with the slowly varying envelope approximation (SVEA), both schemes of generalized Douglas(GD)and conventional central-difference(CN)have been respectively used to disperse lightwave transmission equation, and have been compared each other. The results showed that the former is more accurate. The explicit and implicit expressions of absorbing and transparent boundary condition have been derived for the GD scheme in TD-BPM, respectively.
8.By the example, it was proved that diffusion of error from single point subdomain integration is more slow than central finit difference.
10.The third part relatively analyzed Central America two countries concerning the law-making which lines up dirty power to trade and practice condition, and their difference.
