Multiscale Modeling of Blood Flow and Soft Matter

This work presents multiscale modeling of blood °ow and polymer suspensions which re-quires the use of heterogeneous modeling approaches. A hybrid method based on coupling the Molecular Dynamics (MD) method, the Dissipative Particle Dynamics (DPD) method, and the incompressible Navier-Stokes (NS) equations is developed and is called the Triple-Decker algorithm. MD, DPD, and NS are formulated in separate subdomains and are coupled via an overlapping region by communicating state information at the subdomain boundaries. The triple-decker algorithm is veri¯ed for several prototype °ows such as Cou-ette, Poiseuille, and lid-driven cavity °ow. A three-dimensional multiscale red blood cell (RBC) model is developed and is able to predict RBC mechanics, rheology, and dynamics in agreement with experiments. Based on an analytic theory, the modeled membrane properties can be uniquely related to the exper-imentally established RBC macroscopic properties without any adjustment of parameters. The developed model is applied to modeling infected RBCs in malaria where RBC mem-brane properties can dramatically change. Blood °ow is simulated in microtubes for di®erent diameters and hematocrit values. The blood °ow model captures the well-known Fahraeus