MORE: talks by Helena Švihlová & Martin Lanzendörfer

The talk Modeling of flow in stenotic valves and arteries, by Helena Švihlová, will be held on Monday March 9, 2015 at 8:30 in room K4. After that, Martin Lanzendörfer will present the talk Numerical experiments for slider bearing problem.


Abstract (Helena Švihlová's talk)

A stenosis in the cardiovascular system is a reduction in cross-sectional area of a structure across which blood flows due to the plack or other incapabillities. Interventional and surgical treatments have provided improvements in survival, cardiac function, and functional capacity. Still, accurate and precise assessment of stenosis severity is required in order to appropriately decide whether and what type of treatment is warranted for a given lesion.

Current approaches to interpreting non-invasive data are still incapable of ascertaining hemodynamic stenosis severity. Various methods have been used to evaluate stenoses by either anatomic or physiologic criteria. In this work, we use full solution of the incompressible Navier-Stokes equation for determination of the blood energy dissipation and the pressure differences across cardiovascular stenoses, which can be applied to non-invasive diagnostic modalities.

We will start with the flow in different simplified geometries of the stenotic vessels to obtain the reference velocity field and pressure drop across the stenosis and compute correspond- ing dissipation. Finally, we discuss two approaches to obtain the pressure directly from a measured velocity field.

Abstract (Martin Lanzendörfer's talk)

The talk will concentrate on numerical experiments performed as a parametric study of a slider bearing flow problem. The slider bearing is one of the traditional simple settings studied in the theory of lubrication. While in the classical results the (newtonian) Stokes equations are reduced into the Reynolds approximation, or later the inertial or non-newtonian corrections are added to this approximation, nowadays a full-system (CFD) approach is available and the researchers are tempted to use that instead. We will follow this course with an incompressible pressure-thickening and shear-thinning lubricant, compare some of the results and comment on the advantages and on some issues (namely those on the artificial boundaries).