Design and Particle Image Velocimetry Investigation of a Turbulent Mini-Jet Hemolysis Testing Apparatus

Hemolysis is the break up of red blood cells, and is a condition that is of concern during the design process of blood contacting prostheses. In turbulent flows, hemolysis has been most often correlated to Reynolds shear stress. Mini-scale turbulent jets have been used for hemolysis experiments because they allow for explicit control of shear. Quantitative predictions of hemolysis from shear stress are unreliable, with experimentally determined threshold Reynolds stresses for turbulent shear flow range from 400Pa to 5000Pa, with recent experiments at 800Pa. Reynolds stresses are a statistic of large scale turbulence, and act at spatial scales much larger than that of a red blood cell. It has been suggested in literature that hemolysis may be related to stresses induced by turbulent energy dissipation, which acts as a spatial scale closer to that of a red blood cell. The dissipation of turbulence kinetic energy occurs at the Kolmogorov scales, which is generally similar in scale to that of a red blood cell.