Peng, Gaozhu. Multiphysics computations on celluar interaction in complex geometries and vortex-accelerated vorticity deposition in Richtmyer-Meshkov instability. Retrieved from https://doi.org/doi:10.7282/T3513ZJW
DescriptionThe cellular interactions during leukocyte margination and adhesion cascade in
cardiovascular microcirculations are multi-scale and multiphysics phenomena, involving fluid flow, cell mechanics, chemical reaction kinetics and transport, fluid structure interaction. The vascular network in vivo has rather complicated topology unlike straight and flat channels and pipes where most biological experiments in vitro and numerical simulations are carried. A computational framework is formulated towards a goal of building a virtual blood vessel system to simulate the hydrodynamic and kinetic interactions of blood cells in complex vascular geometries, including vascular network bifurcations and irregular shapes of the endothelial monolayer lining the blood vessel lumen in vivo. Mixed front tracking, immersed boundary and ghost cell methods are
applied. The codes are benchmarked and validated with five selected problems. We find that the erythrocyte-leukocyte interaction, leukocyte-leukocyte interaction, and vascular geometries play important roles in leukocyte margination, initial tethering and adhesion to the vascular endothelium.
In part II of the dissertation, we studied the two-dimensional microscale Richtmyer-Meshkov interfaces and discovered the self-driven vortex-accelerated vorticity deposition (VAVD) process. Opposite-signed secondary vorticity deposited by the VAVD is rolled into vortex double layers which are extremely unstable and lead to enhanced fluid mixing. The VAVD process examined and the new quantification procedure, the circulation rate of change, comprise a new vortex paradigm for examining the effect of specific initial conditions on the evolution of Richtmyer-Meshkov and Rayleigh-Taylor interfaces through intermediate times.