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arXiv 2109.02792math.NAcs.NA
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反应扩散方程能量变分方程组的二阶精度算子分裂格式

A second-order accurate, operator splitting scheme for reaction-diffusion systems in an energetic variational formulation

Chun Liu, Cheng Wang, Yiwei Wang

摘要:

针对具有详细平衡项的反应扩散方程组,提出了一种时间上二阶精度、保正性和无条件能量稳定的算子分裂数值格式,并分析了该格式的收敛性.该方案是基于能量变分公式设计的,其中反应部分根据反应轨迹重新制定,反应和扩散部分耗散相同的自由能。在反应阶段,反应轨迹方程由二阶Crank-Nicolson型方法近似。唯一的可解性,保正性和能量稳定性的基础上建立的凸性分析。在扩散阶段,如果扩散系数是常数,则应用精确积分器,如果扩散过程变为非线性,则应用Crank-Nicolson型方案。在任何一种情况下,保正性和能量稳定性都可以在理论上成立。此外,在这两个阶段的数值算法相结合的斯特朗分裂方法导致二阶精度,结构保持原反应扩散系统的计划。数值实验表明,所提出的方案的准确性。

英文摘要:

A second-order accurate in time, positivity-preserving, and unconditionally energy stable operator splitting numerical scheme is proposed and analyzed for the system of reaction-diffusion equations with detailed balance. The scheme is designed based on an energetic variational formulation, in which the reaction part is reformulated in terms of the reaction trajectory, and both the reaction and diffusion parts dissipate the same free energy. At the reaction stage, the reaction trajectory equation is approximated by a second-order Crank-Nicolson type method. The unique solvability, positivity-preserving, and energy-stability are established based on a convexity analysis. In the diffusion stage, an exact integrator is applied if the diffusion coefficients are constant, and a Crank-Nicolson type scheme is applied if the diffusion process becomes nonlinear. In either case, both the positivity-preserving property and energy stability could be theoretically established. Moreover, a combination of the numerical algorithms at both stages by the Strang splitting approach leads to a second-order accurate, structure-preserving scheme for the original reaction-diffusion system. Numerical experiments are presented, which demonstrate the accuracy of the proposed scheme.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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