Human red blood cell hemolysis in a turbulent shear flow: contribution of Reynolds shear stresses.

Various previous models used in studying red blood cell (RBC) hemolysis in turbulent shear flows are reviewed from a fluid dynamic point of view. The effect of turbulent shear stress (Reynolds shear stress, tau R) on RBC hemolysis is investigated utilizing a submerged axisymmetric jet flow field. A detailed survey of the flow field is made with a laser Doppler anemometer system to obtain contour maps of the mean velocity distributions, relative turbulence intensities, and tau R distributions in the field prior to conducting the experiment of sampling and analyzing the cells free-hemoglobin in the field. A new two-point sampling technique, developed in this laboratory, allows collections of RBC samples from selected locations in the flow field so that a relationship between the local shear stress level and the cell damage may be established. The threshold level of tau R responsible for incipient hemolysis is found to be approximately 400 Newtons per square meter (N/m2), below which a sublethal region of zero hemolysis is observed.