Existing mapped WENO schemes can hardly prevent spurious oscillations while preserving high resolutions at long output times. We reveal in this paper the essential reason for such phenomena. It is actually caused by that the mapping function in these schemes can not preserve the order of the nonlinear weights of the stencils. The nonlinear weights may be increased for non-smooth stencils and be decreased for smooth stencils. It is then indicated to require the set of mapping functions to be Order-Preserving in mapped WENO schemes. Therefore, we propose a new mapped WENO scheme with a set of mapping functions to be order-preserving which exhibits a remarkable advantage over the mapped WENO schemes in references. For long output time simulations, the new scheme has the capacity to attain high resolutions and avoid spurious oscillations near discontinuities meanwhile.
翻译:现有已绘制的WENO计划很难防止虚假的振动,同时在长时间输出时保留高分辨率。 我们在本文件中揭示出此类现象的基本原因。 事实上,这是因为这些计划中的绘图功能无法保持Stencils的非线性重量的顺序。 非线性重量对于非线性突变可能会增加,对于光滑的速变则会降低。 然后,我们表示,要求一组绘图功能必须是在已绘制的WENO计划中按顺序保存。 因此,我们提出一个新的已绘制的WENO计划,配有一套绘图功能,在参考中显示相对于已绘制的WENO计划的显著优势。 对于长期的输出时间模拟,新计划有能力达到高分辨率,避免同时发生接近不连续的虚假振动。