A bidirectional coupling procedure applied to multiscale respiratory modeling

A.P. Kuprat, S. Kabilan, J.P. Carson, R.A. Corley, D.R. Einstein
2013 Journal of Computational Physics  
In this study, we present a novel multiscale computational framework for efficiently linking multiple lower-dimensional models describing the distal lung mechanics to imaging-based 3D computational fluid dynamics (CFD) models of the upper pulmonary airways in order to incorporate physiologically appropriate outlet boundary conditions. The framework is an extension of the Modified Newton's Method with nonlinear Krylov accelerator developed by Carlson and Miller [1, 2, 3] . Our extensions include
more » ... the retention of subspace information over multiple timesteps, and a special correction at the end of a timestep that allows for corrections to be accepted with verified low residual with as little as a single residual evaluation per timestep on average. In the case of a single residual evaluation per timestep, the method has zero additional computational cost compared to uncoupled or unidirectionally coupled simulations. We expect these enhancements to be generally applicable to other multiscale coupling applications where timestepping occurs. In addition we have developed a "pressure-drop" residual which allows for stable coupling of flows between a 3D incompressible CFD application and another (lowerdimensional) fluid system. We expect this residual to also be useful for coupling non-respiratory incompressible fluid applications, such as multiscale simulations involving blood flow. ☆ This document is a collaborative effort.
doi:10.1016/j.jcp.2012.10.021 pmid:24347680 pmcid:PMC3856712 fatcat:j77ijbn5andirdegsztb6rops4