论文标题
通过使用指数近似空间提高五阶WENO方案的准确性
Improving accuracy of the fifth-order WENO scheme by using the exponential approximation space
论文作者
论文摘要
这项研究的目的是开发一种新型的WENO方案,以改善众所周知的五阶Weno方法的性能。近似空间由指数多项式组成,其张力参数可以优化以符合数据的特定特征,与多项式近似空间相比,结果更好。但是,找到最佳的张力参数是一个非常重要且困难的问题,确实是一个积极研究的话题。在这方面,这项研究引入了一种实用方法来确定最佳张力参数,并考虑到第五阶WENO方案的设置下的张力参数与指数多项式插值的准确性之间的关系。结果,提出的WENO方案比其他五阶Weno方法更好地提高了准确性(即六阶),而不会在临界点上丧失准确性。提供详细的分析以验证提高的收敛速率。此外,我们提出了基于$ l^1 $ norm方法的改进的非线性权重,以及新的全球平滑度指标。提出的非线性权重大大减少了数值耗散,同时在平滑区域获得更好的分辨率。提出了各种基准测试问题的一些实验结果,以证明新方案的能力。
The aim of this study is to develop a novel WENO scheme that improves the performance of the well-known fifth-order WENO methods. The approximation space consists of exponential polynomials with a tension parameter that may be optimized to fit the the specific feature of the data, yielding better results compared to the polynomial approximation space. However, finding an optimal tension parameter is a very important and difficult problem, indeed a topic of active research. In this regard, this study introduces a practical approach to determine an optimal tension parameter by taking into account the relationship between the tension parameter and the accuracy of the exponential polynomial interpolation under the setting of the fifth-order WENO scheme. As a result, the proposed WENO scheme attains an improved order of accuracy (that is, sixth-order) better than other fifth-order WENO methods without loss of accuracy at critical points. A detailed analysis is provided to verify the improved convergence rate. Further, we present modified nonlinear weights based on $L^1$-norm approach along with a new global smoothness indicator. The proposed nonlinear weights reduce numerical dissipation significantly, while attaining better resolution in smooth regions. Some experimental results for various benchmark test problems are presented to demonstrate the ability of the new scheme.