BIO10: Comparison of Interlaboratory CFD Simulations of the FDA Benchmark Blood Pump Model

Purpose of Study: Computational fluid dynamics (CFD) is widely used in the design and assessment of medical devices. To be relied upon to inform regulatory decisions, however, CFD credibility must be established by performing verification and validation. Toward this end, FDA and academic collaborators established a benchmark centrifugal blood pump model for CFD validation. An open interlaboratory study was initiated in which participants from around the world submitted 24 CFD simulations of the pump. Here, we report the complete results of the interlaboratory study including comparisons of the CFD predictions with experimental measurements. Methods Used: Participants simulated 6 pump conditions with flow rates ranging from 2.5–7.0 L/min and rotational speeds of 2500–3500 rpm. We performed detailed analyses of the anonymized results at three test conditions: (1) 2.5 L/min at 3500 rpm, (2) 6.0 L/min at 2500 rpm, and (3) 6.0 L/min at 3500 rpm. We specifically analyzed predictions of the pump pressure head, velocity distributions throughout the pump, and hemolysis. Summary of Results: Participants submitted results from 14 steady-state and 10 transient simulations using a wide range of CFD solvers, mesh resolutions, and turbulence models. In general, there was not a strong correlation between mesh resolution or turbulence model with CFD accuracy. Most CFD predictions of the pump pressure head were within two standard deviations of the mean experimental data, except at the 6.0 L/min, 2500 rpm condition for which only 16 of 23 submissions were within this range. Unsteady simulations of the velocity field generally agreed better with the experiments within the rotor region, but showed little advantage over steady simulations in the outlet diffuser. Hemolysis predictions varied widely for the 8 participants who submitted results. This study provides insight into the accuracy of CFD simulations of mechanical circulatory support devices from a wide range of users in the medical device community.