Minimization of Hemolysis and Improvement of the Hydrodynamic Efficiency of a Circulatory Support Pump by Optimizing the Pump Flowpath

Abstract

The present study focuses on the development of methods for design calculation and optimization of the circulatory support pump flowpath. The object of this study is the flowpath of an axial flow pump consisting of a straightener, an impeller, and a diffuser. The working fluid has constant density and viscosity that are close to the physiological parameters of blood of a healthy human. The fluid is considered to be incompressible; the flow is considered steady. Red blood cells in the stream are simulated with non-interacting spherical particles whose trajectories are considered as the trajectories of movement of red blood cells. Equivalent shear stress is calculated at each point of the particle trajectory. The damage parameter is calculated based on the current level of the equivalent shear stress and the time of exposure to shear stress. The criteria of maximum efficiency and minimal hemolysis are used as the optimization criteria. The flowpath is optimized according to these two criteria and local optimum parameters for the suggested initial geometry are determined.