LARGE-DEFORMATION OF RED-BLOOD-CELL GHOSTS IN A SIMPLE SHEAR-FLOW

Red blood cells are known to change shape in response to local flow co nditions. Deformability affects red blood cell physiological function and the hydrodynamic properties of blood. The immersed boundary method is used to simulate three-dimensional membrane-fluid how interactions for cells with the same internal and external fluid viscosities. The method has been validated for small deformations of an initially spher ical capsule in simple shear flow for both neo-Hookean and the Evans-S kalak membrane models. Initially oblate spheroidal capsules are simula ted and it is shown that the red blood cell membrane exhibits asymptot ic behavior as the ratio of the dilation modulus to the extensional mo dulus is increased and a good approximation of local area conservation is obtained. Tank treading behavior is observed and its period calcul ated. (C) 1998 American Institute of Physics.