In this paper the authors study a non-linear elliptic-parabolic system, which is motivated by mathematical models for lithium-ion batteries. One state satisfies a parabolic reaction diffusion equation and the other one an elliptic equation. The goal is to determine several scalar parameters in the coupled model in an optimal manner by utilizing a reliable reduced-order approach based on the reduced basis (RB) method. However, the states are coupled through a strongly non-linear function, and this makes the evaluation of online-efficient error estimates difficult. First the well-posedness of the system is proved. Then a Galerkin finite element and RB discretization are described for the coupled system. To certify the RB scheme hierarchical a-posteriori error estimators are utilized in an adaptive trust-region optimization method. Numerical experiments illustrate good approximation properties and efficiencies by using only a relatively small number of reduced basis functions.
翻译:本文研究了一个由锂离子电池数学模型驱动的非线性椭圆-抛物耦合系统,其中一个状态变量满足抛物型反应扩散方程,另一个满足椭圆方程。研究目标是通过采用基于约化基(RB)方法的可靠降阶途径,以最优方式确定耦合模型中的若干标量参数。然而,状态变量通过强非线性函数耦合,这使得在线高效误差估计的评估变得困难。首先证明了该系统的适定性,随后描述了耦合系统的Galerkin有限元与RB离散化方案。为验证RB方案,在自适应信赖域优化方法中采用了分层后验误差估计器。数值实验表明,仅使用相对较少的约化基函数即可获得良好的逼近性质与计算效率。