Low Order Nonconforming Expanded Characteristic- Mixed Finite Element Method for the Convection- Diffusion Problem
نویسندگان
چکیده
A low order nonconforming finite element method is proposed for the convection-diffusion equations with the expanded characteristic-mixed finite element scheme. The method is a combination of characteristic approximation to handle the convection part in time and a expanded nonconforming mixed finite element spatial approximation to deal with the diffusion part. In the process, the interpolation operator is employed instead of the so-called elliptic projection which is an indispensable tool used for the convergence analysis in the previous literature. When the exact solutions belong to H2(Ω) instead of H3(Ω), the corresponding optimal order error estimates in L2-norm are obtained by use of some distinct properties of the nonconforming finite elements.
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