Multiscale coupling algorithms using parareal style structures

Multiscale coupling algorithms using parareal style structures

We are developing a data-driven parallel-in-time iterative method to solve the homogeneous second-order wave equation. The new method involves a coarse-scale propagator and a fine-scale propagator which fully resolves the medium using finer spatial grid and shorter time steps. The fine-scale propagator is run in parallel for short time subintervals. The two propagators are coupled in an iterative way similar to the standard parareal method. We train a Neural Network, which structure mimics the physics of wave propagation, to enhance the accuracy of the coarse-scale propagator such that the parareal iteration stabilizes and hence converges.

Simulation

Wave propagating through Marmousi velocity profile.

Publications

  • H. Nguyen, and R. Tsai. "A stable parareal-like method for the second order wave equation." Journal of Computational Physics (2020). Accepted.
  • G. Ariel, H. Nguyen, and R. Tsai. "\theta-parareal schemes." arXiv preprint arXiv:1704.06882 (2017).