提出了数值求解一维非定常对流扩散方程的一种两层四阶紧致隐式差分格式,其截断误差为O(τ^2+h^4).采用von Neumann方法证明了格式是无条件稳定的,并且由于每一时间层上只用到了3个网格点,所以可直接采用追赶法求解差分方程.数值实验结果验证了该方法的精确性和可靠性.
A high-order two-level compact implicit difference scheme is proposed to solve the onedimensional(1D) unsteady convection-diffusion equation. The truncation of the scheme is O(x^2 +h^4). It is proved to be unconditionally stable by von Neumann method. Because only three points are used at each time level, the difference equation can be solved by the method of forward elimination and backward substitution. Numerical results validate the efficiency and dependability.