Computational flow dynamics of complex fluids

In this work several multiphase flow problems with complex boundaries are numerically analyzed: The long-time diffusion coefficient and flow transition in the shear flow of inelastic, rough, hard granular spheres is analyzed by molecular dynamics simulations. Two-phase lattice-Boltzmann method is verified for modelling of the capillary rise Phenomenon and analyzed for related parameters such as dynamic contact angle and the capillary number. The lattice-Boltzmann code is also used to analyze the rheology of liquid-particle suspensions; the dependence of the viscosity of the suspension on the concentration of particles and shear rate in a Couette flow geometry. Finally the low Reynolds number channel flow of liquid-particle suspensions is studied, in which suspended particles that can attach on channel walls or detached. Phase transitions are observed such as first order like transition to a meandering phase. The meandering phase is followed by a necking phase and finally a transition to a fully blocked flow channel takes place. A well known phenomenon is the formation of blood cholesterol clogs in heart coronary arteries that can lead to heart attack (myocardial infarction).

Autorentext

PhD (Applied Physics, 2003), MSc (Energy Conversion), BSc (Mechanical Engineering). R&D Manager at Karibu Engineering Ltd., since 2004, Jyväskylä, Finland.