ABSTRACT
An improved finite difference method with a compact correction term is proposed to solve the Poisson’s equations. The compact correction term is developed by coupled high-order compact and low-order classical finite difference formulations. The numerical solutions obtained by the classical finite difference method are considered as fundamental solutions with lower accuracy, whereas a compact correction term is added into the source term of classical discrete formulation to improve the accuracy of numerical solutions. The proposed method can be extended from two-dimensional to multidimensional cases straightforwardly. Numerical experiments are carried out to verify the accuracy and efficiency of this method.
Nomenclature
ae | = | coefficients of discretized Poisson’s equation |
ai | = | coefficients of discretized equation for second derivative |
an | = | coefficients of discretized Poisson’s equation |
ap | = | coefficients of discretized Poisson’s equation |
as | = | coefficients of discretized Poisson’s equation |
bi | = | coefficients of discretized equation for second derivative |
= | compact correction term | |
ci | = | coefficients of discretized equation for second derivative |
f | = | forcing function |
H | = | numerical method with higher-order accuracy |
L | = | numerical method with lower-order accuracy |
Lx | = | horizontal length of computational domain |
Ly | = | vertical length of computational domain |
M | = | number of grid points in x-direction |
N | = | number of grid points in y-direction |
x | = | horizontal coordinate |
xi | = | grid point in x-direction |
y | = | vertical coordinate |
yi | = | grid point in y-direction |
αi | = | coefficient of discretized equations for second derivative |
βi | = | coefficient of discretized equations for second derivative |
γ | = | stretch ratio of neighbor grid |
ξ | = | fundamental grid points with uniform intervals in the domain [−1, 1] |
Δxi | = | grid spacing in x-direction |
Δyi | = | grid spacing in y-direction |
φ | = | variable value |
φi,j | = | numerical solution |
= | numerical solution with lower accuracy | |
Ω | = | computational domain |
Nomenclature
ae | = | coefficients of discretized Poisson’s equation |
ai | = | coefficients of discretized equation for second derivative |
an | = | coefficients of discretized Poisson’s equation |
ap | = | coefficients of discretized Poisson’s equation |
as | = | coefficients of discretized Poisson’s equation |
bi | = | coefficients of discretized equation for second derivative |
= | compact correction term | |
ci | = | coefficients of discretized equation for second derivative |
f | = | forcing function |
H | = | numerical method with higher-order accuracy |
L | = | numerical method with lower-order accuracy |
Lx | = | horizontal length of computational domain |
Ly | = | vertical length of computational domain |
M | = | number of grid points in x-direction |
N | = | number of grid points in y-direction |
x | = | horizontal coordinate |
xi | = | grid point in x-direction |
y | = | vertical coordinate |
yi | = | grid point in y-direction |
αi | = | coefficient of discretized equations for second derivative |
βi | = | coefficient of discretized equations for second derivative |
γ | = | stretch ratio of neighbor grid |
ξ | = | fundamental grid points with uniform intervals in the domain [−1, 1] |
Δxi | = | grid spacing in x-direction |
Δyi | = | grid spacing in y-direction |
φ | = | variable value |
φi,j | = | numerical solution |
= | numerical solution with lower accuracy | |
Ω | = | computational domain |