论文标题
用于多维有限元模拟的基于凸优化的结构传播过滤器
Convex Optimization-Based Structure-Preserving Filter For Multidimensional Finite Element Simulations
论文作者
论文摘要
在模拟科学中,希望尽可能准确地捕获现实世界中的问题特征。对于科学模拟(例如有限元方法(FEM)和有限体积方法(FVM))而流行的方法使用分段多项式来近似问题的各种特征,例如浓度曲线和整个域的温度分布。多项式容易在捕获复杂的轮廓时创建诸如吉布斯振荡之类的人工制品。必须采用有效而准确的方法来处理此类不一致之处,以获得准确的模拟。这通常需要处理化学物质浓度的负值,超过100的百分比值以及其他此类问题。我们认为在部分微分方程(PDE)的背景下考虑了这些不一致之处。我们提出了一个基于凸优化的创新过滤器,以处理基于多项式模拟中观察到的不一致之处。在两个或三个空间维度中,解决与结构保存相关的问题涉及其他复杂性。我们介绍了具有多维PDE的结构保存过滤器的构建和应用。使用的方法,例如在域中任意点的多项式评估和优化的根夹来识别关注点的方法,以提高滤波器效率,可用性和鲁棒性。最后,我们使用不连续的Galerkin公式在2D和3D中进行了数值实验,并证明了过滤器保留所需结构的功效。作为现实世界的应用,已经审查了涉及血小板聚集和血液凝结的数学生物学模型的实施,并通过应用建议的结构贴合过滤器来解决该模型的FEM实施的问题。
In simulation sciences, it is desirable to capture the real-world problem features as accurately as possible. Methods popular for scientific simulations such as the finite element method (FEM) and finite volume method (FVM) use piecewise polynomials to approximate various characteristics of a problem, such as the concentration profile and the temperature distribution across the domain. Polynomials are prone to creating artifacts such as Gibbs oscillations while capturing a complex profile. An efficient and accurate approach must be applied to deal with such inconsistencies in order to obtain accurate simulations. This often entails dealing with negative values for the concentration of chemicals, exceeding a percentage value over 100, and other such problems. We consider these inconsistencies in the context of partial differential equations (PDEs). We propose an innovative filter based on convex optimization to deal with the inconsistencies observed in polynomial-based simulations. In two or three spatial dimensions, additional complexities are involved in solving the problems related to structure preservation. We present the construction and application of a structure-preserving filter with a focus on multidimensional PDEs. Methods used such as the Barycentric interpolation for polynomial evaluation at arbitrary points in the domain and an optimized root-finder to identify points of interest improve the filter efficiency, usability, and robustness. Lastly, we present numerical experiments in 2D and 3D using discontinuous Galerkin formulation and demonstrate the filter's efficacy to preserve the desired structure. As a real-world application, implementation of the mathematical biology model involving platelet aggregation and blood coagulation has been reviewed and the issues around FEM implementation of the model are resolved by applying the proposed structure-preserving filter.