Large-eddy simulation of physiological pulsatile flow through a constricted channel

Abstract

In this thesis, large-eddy simulation (LES) is used to simulate both Newtonian and non-Newtonian physiological pulsatile flows in constricted channels to gain insights into the physical phenomenon of laminar-turbulent flow transition due to the presence of an artificial arterial stenosis. The advanced dynamic nonlinear subgrid-scale stress (SGS) model of Wang and Bergstrom (DNM) was utilized to conduct numerical simulations and its predictive performance was examined in comparison with that of the conventional dynamic model (DM) of Lilly.

An in-house LES code has been modified to conduct the unsteady numerical simulations, and the results obtained have been validated against available experimental and direct numerical simulation (DNS) results. The physical characteristics of the flow field have been thoroughly studied in terms of the resolved mean velocity, turbulence kinetic energy, viscous wall shear stress, and turbulence energy spectra along the central streamline of the domain.