Validated Guidelines for Simulating Centrifugal Blood Pumps.

Area of Science:

• Biomedical Engineering
• Computational Science

Background:

• Rotary blood pumps (RBPs) are crucial ventricular assist devices for heart failure patients.
• Computational Fluid Dynamics (CFD) is used for RBP development, but simulation inconsistencies hinder accurate performance prediction.
• Lack of standardized validation makes it difficult to assess CFD simulation accuracy for RBPs.

Purpose of the Study:

• To determine optimal CFD simulation settings for accurate rotary blood pump (RBP) performance prediction.
• To validate simulation techniques against the US Food and Drug Administration (FDA) benchmark model for centrifugal RBPs.
• To address inconsistencies in CFD predictions for RBP development.

Main Methods:

• Investigated the impact of mesh density, interface position, time step size, and various turbulence models (k-ε realizable, k-ω SST, RSM, SAS, SBES) on CFD predictions.
• Employed steady and transient simulations with a sliding mesh approach.
• Validated simulation results against published FDA benchmark data for a centrifugal RBP.

Main Results:

• Steady simulations with the k-ω turbulence model achieved 5% pressure prediction accuracy but showed unphysical velocity fields.
• Transient simulations using the Stress-Blended Eddy Simulation (SBES) turbulence model accurately predicted velocity fields and pressure rise within experimental variation.
• SBES simulations proved more robust in capturing complex flow dynamics compared to steady-state approaches.

Conclusions:

• The Stress-Blended Eddy Simulation (SBES) turbulence model is recommended for accurate rotary blood pump (RBP) performance prediction in early development stages.
• Accurate CFD simulations are vital for reliable RBP design and to minimize inconsistencies in ventricular assist device development.
• Validated simulation settings, like SBES, can improve the predictability and reliability of CFD in medical device engineering.