Evaluation of energy dissipation rate as a predictor of mechanical blood damage.

A long-standing goal in the field of biofluid mechanics has been to reliably predict hemolysis across the wide range of flows that can occur in prosthetic cardiovascular devices. A scalar representation of the complex three-dimensional fluid stresses that are exerted on cells is an attractive alternative for the simplicity that it lends to the computations. The appropriateness of the commonly used von-Mises-like scalar stress as a universal hemolysis scaling parameter was previously evaluated, finding that erythrocyte membrane tensions calculated for laminar shear and extensional flows and for three cases of turbulent flow were widely divergent for the same value of scalar stress. The same techniques are applied in this study to laminar and turbulent flows that each have the same energy dissipation rate. Results showed that agreement of membrane tension between laminar shear and turbulent shear inside an eddy was improved relative to the common scalar stress cases, but disagreement between laminar shear and laminar extension remained the same and disagreement between laminar shear and other turbulent flows increased. It is therefore concluded that energy dissipation rate alone is also likely not sufficient to universally scale blood damage across the range of different flows that can be encountered clinically.