Session MC - Micro-Fluid Dynamics IX.
MIXED session, Tuesday afternoon, November 23
Grand III, Westin Seattle
A dynamically stabilized microcarrier is a rigid spherical particle with an eccentric but axisymmetric mass distribution. These microcarriers are used for control studies in culturing biological cells employing NASA designed rotating wall vessel bioreactors. Due to the eccentric mass distribution, the rotation of the particle about its own axis is prevented and hence these spheres always remain upright during motion in the bioreactor while experiencing shear. We have developed an Arbitrary Lagrangian Eulerian scheme for rotating flows to capture the dynamics of such microcarriers. Euler equations describing the rotational motion are solved in a body-fixed frame while the translational equations are described in a frame rotating with the bioreactor (fluid-filled cylinder). Motion of a single lighter-than-fluid microcarrier is presented and the trajectory of the particle is compared qualitatively with experiments conducted with such microcarriers in rotating flows. Hydrodynamic forces and flow structure around the dynamically stabilized particle are also compared with a uniform density spherical particle having the same radius and mass as the dynamically stabilized microcarrier.