  We numerically investigate margination of white blood cells and demonstrate
the dependency on a number of conditions including hematocrit, the
deformability of the cells and the Reynolds number. A detailed mesoscopic
hydrodynamic Helfrich-type model is derived, validated and used for the
simulations to provides a quantitative description of the margination of white
blood cells. Previous simulation results, obtained with less detailed models,
could be confirmed, e.g. the largest probability of margination of white blood
cells at an intermediate range of hematocrit values and a decreasing tendency
with increasing deformability. The consideration of inertia effects, which
become of relevance in small vessels, also shows a dependency and leads to less
pronounced margination of white blood cells with increasing Reynolds number.
