Simulations of cancer cell transport require accurately modeling mm-scale and longer trajectories through a circulatory system containing trillions of deformable red blood cells whose intercellular interactions require submicron fidelity. Using a hybrid CPU-GPU approach we extend the advanced physics refinement (APR) method to couple a finely-resolved region of explicitly-modeled red blood cells to a coarsely-resolved bulk fluid domain. We further develop algorithms that: capture the dynamics at the interface of differing viscosities maintain hematocrit within the cell-filled volume and move the finely-resolved region and encapsulated cells while tracking an individual cancer cell. Comparison to a fully-resolved fluid-structure interaction model is presented for validation. Finally we use the advanced APR method to simulate cancer cell transport over a mm-scale distance while maintaining a local region of RBCs using a fraction of the computational power required to run a fully-resolved model.
