Diana Broboana

Modeling the Vortical Structures in Hemodynamics of Small Vessels and Capillaries

The paper is dedicated to the flow modeling in micro‐bifurcations, with application in hemodynamics of vessels and capillaries located in the endothelial wall. In particular, the present study is focused to the experimental and numerical simulations of the vortical patterns in micro‐junctions for Newtonian and Carreau—Yasuda models at Re≪1.

Free surface flow over the broad — Crested weir

The free surface flow around immersed bodies is a current CFD problem in applied fluid mechanics. The aim of this paper is to present a comparative study between experiments and numerical simulations of the flow around immersed bodies in vicinity of the free surface. The free surface flows in a planar channel were experimentally investigated in subcritical regim at Reynolds number Re = 3500, respectively Froude number Fr = 0.06. Numerical simulations are performed with the FLUENT code, RNG k-ε turbulent model and the volume of fluid (VOF) model for calculating the free surface geometry being used. The computational results showed a close agreement with experimental data obtained in the laboratory for the flow over the broad - crested weir with smooth and patterned surfaces.

Numerical modelling of the shear banding flow in the proximity of micro-structures

The paper is concerned with the numerical modelling of the viscous steady flows in the vicinity of 3D micro-structures. The solutions are obtained for the Carreau generalized Newtonian model with negative flow index n. The main goal of the study is to investigate the shear banding formation between two rotating plates, in the presence of micro-pillars and micro-channels. The phenomenon is generated by the material instability of non-homogeneous complex fluids subjected to different shear rates under a constant shear stress. Simulations are performed in 3D configurations with the Ansys Fluent code.

Jetting flow and diffusion process in the vicinity of convex surfaces

The paper is concerned with the experimental and numerical investigations of a laminar jetting flow impacting immersed convex bodies, the so called Coanda effect. Numerical solutions of the coupled Navier-Stokes and diffusion equations are obtained for Hele-Shaw flow configurations, particularly designed to analyze the studied phenomenon, related to the spreading of a solute by an immersed water jet in a flow domain filled with convex/cylindrical bodies. The computed 2D flow patterns (qualitatively confirmed by experiments) and stresses distributions on the convex wall are directly linked with the spreading of solute on the convex surfaces, phenomenon which triggers and controls the diffusion process.

Investigation of Vortical Structures in Bifurcations

The paper presents experimental visualizations and numerical simulations of vortical structures in a 3D bifurcation at Re = 150. The studies are focused to the biofluid applications, in relation to the influences induced on the flow structure within the vessels by the presence of stent. The results evidenced the changes of normal Newtonain flow patter due to stent local geometry and also the influence induced by the shear thinning of Carreau model.