MODIFICATION OF THE SPALART–ALLMARAS MODEL FOR HEMOLYTIC SHEAR FLOW SIMULATION WITH PIV EXPERIMENT

Abstract

Hemolysis in blood-contacting devices severely affects the health of users, and computation fluid dynamics (CFD) simulation is a crucial method for hemolysis analysis. Medical equipment has high requirements for simulation accuracy. Modification of the turbulence model is one of the most effective ways to improve efficiency. In this study, we designed nozzle models to simulate hemolytic shear flow, varying the degree of shear flow through different nozzle orifice sizes. The study acquires microscopic flow results through Particle Image Velocimetry (PIV) experiments, and the Sparlart–Allmaras (S–A) model was modified based on the experimental results. In the study, we obtained the influence characteristics of the model coefficients on the simulation results and completed the accuracy correction. The results showed that the model coefficient [Formula: see text] has the most significant effect on the simulation results. Correcting [Formula: see text] to about 200% of the standard value can significantly improve the simulation accuracy, and the high shear flow intensity corresponds to a slightly lower correction value. The model modification eliminates the simulation error in the high-speed area, and the comparison results show that it is superior to the standard turbulence model.