Assoc. Prof. Lisa Prahl Wittberg - Department of Mechanics - KTH

Title: Blood flow – critical fluid mechanics (Strömningsmekanik – på blodigt allvar)

Abstract:Fluid mechanics, and especially multi-phase flows, are found in several vital processes. Inhalation of particles or aerosols as well as how these particles deposit in our airways can be just as healthful (pharmaceutical) as harmful (air pollution).  Blood flow, which this presentation will focus on, is another example of fluid mechanics found in our body.

Blood is a complex fluid that consists of red and white blood cells, platelets and plasma, an aquatic solution that contain salts and molecules of different chemical character and sizes.  Fluids such as blood may have a viscosity, as well as density, that vary both in time and space. A feature differing blood from a fluid such as water is that the viscosity of water at a given temperature and pressure is constant. Regions with high particle concentrations will commonly be characterized by high viscosity whereas low particle concentrations will have low viscosities.  Therefore it is important to study how the different cells move within the flow field as it is directly coupled to the blood rheology. Moreover, this affects how the blood flows in our vessels, which in turn govern the shear stresses that the vessels walls will be subjected to. One of the reasons for the interest in wall shear stresses is that it is widely recognized that the forming of atherosclerosis has a fluid mechanical component.

In this presentation I will give an overview of the research regarding blood flow and talk about a few medical and engineering applications where it is important that we understand the cause and effect of blood flow.