An adaptive dynamically low-dimensional approximation method for multiscale stochastic diffusion equations
This work addresses the computational cost of solving time-dependent multiscale stochastic PDEs, which is important for uncertainty quantification in engineering and science.
The paper proposes an adaptive dynamically low-dimensional approximation method for multiscale stochastic diffusion equations, combining multiscale basis functions and online adaptive basis functions to improve efficiency and accuracy. Numerical results demonstrate the method's effectiveness.
In this paper, we propose a dynamically low-dimensional approximation method to solve a class of time-dependent multiscale stochastic diffusion equations. A dynamically bi-orthogonal (DyBO) method was developed to explore low-dimensional structures of stochastic partial differential equations (SPDEs) and solve them efficiently. However, when the SPDEs have multiscale features in physical space, the original DyBO method becomes expensive. To address this issue, we construct multiscale basis functions within each coarse grid block for dimension reduction in the physical space. To further improve the accuracy, we also perform online procedure to construct online adaptive basis functions. In the stochastic space, we use the generalized polynomial chaos (gPC) basis functions to represent the stochastic part of the solutions. Numerical results are presented to demonstrate the efficiency of the proposed method in solving time-dependent PDEs with multiscale and random features.