Neumann Boundary Conditions in Coupled 3D-0D Biofluid Networks

The coupling of reduced-dimensional to three-dimensional (3D) models has been addressed in various studies of biomechanical (hemodynamic and pulmonary) flow problems. However, instabilities associated with flow reversal, that is, when outflow boundaries turn into inflow boundaries are still an open problem. Such reversed flow is especially crucial in resporatory flow problems, where static pressure is lower than dynamic pressure. In this work, the comprehensive treatment of biofluid networks via Neumann boundary-condition formulations as proposed in [ V. Gravemeier, A. Comerford, L. Yoshihara, M. Ismail, W.A. Wall, A novel formulation for Neumann inflow boundary conditions in biomechanics. Int. J. Numer. Meth. Biomed. Engng., 2011, in press.] will be introduced. In particular, the extension to coupled 3D-0D problems will be emphasized. This novel approach was successfully tested on a numerical example of a coupled 3D-0D full lung model during spontaneous breathing, and thus showed the power of our approach.     «

The coupling of reduced-dimensional to three-dimensional (3D) models has been addressed in various studies of biomechanical (hemodynamic and pulmonary) flow problems. However, instabilities associated with flow reversal, that is, when outflow boundaries turn into inflow boundaries are still an open problem. Such reversed flow is especially crucial in resporatory flow problems, where static pressure is lower than dynamic pressure. In this work, the comprehensive treatment of biofluid networks...     »