A centrifugal blood pump, also known as a Left Ventricular Assist Device (LVAD), is a life-saving medical device for people with weak hearts. Unlike a real heart that squeezes, this pump uses a spinning part, called an impeller, to move blood. Designing these pumps is very hard because blood can be damaged easily. Engineers use Computational Fluid Dynamics (CFD) to test their designs on a computer. A Centrifugal Blood Pump CFD simulation lets us see exactly how blood flows inside the pump. This helps us find areas where blood cells might break (hemolysis) or where dangerous clots might form (thrombosis). This study of a Centrifugal Pump using Fluent applies a special Rotating Machinery CFD technique to understand the pump’s performance and safety. Our work is guided by the methods in the research paper, “On the Optimization of a Centrifugal Maglev Blood Pump Through Design Variations” [1]

Figure 1: Schematic of the maglev blood pump model used in this Cardiovascular Device Simulation [1].

Simulation Process: Fluent Setup, Applying the MRF Method for Pump Rotation

For this Blood Pump CFD simulation, we started with a detailed 3D model of the maglev pump. To capture all the details of the flow, we created a very fine mesh using 9,495,864 tetrahedral cells. The most important part of this simulation was making the impeller spin correctly. In ANSYS Fluent, we used the Multiple Reference Frame (MRF) method. This powerful technique creates a spinning zone for the impeller and a still zone for the pump casing, allowing us to accurately simulate the pump’s rotation at 3500 rpm.

Figure 2: A section view of the computational mesh used for the Centrifugal Pump Fluent analysis.

Post-processing: CFD Analysis, Visualizing Pump Performance and Blood Safety

The velocity and pressure contours give us a clear, professional visual of the pump’s power. As the impeller spins, it creates spiral pathways that push the blood from the center inlet to the outside outlet. The velocity contour shows that the blood reaches a top speed of 9.6 m/s near the tips of the impeller blades. The pressure contour shows how this speed creates a powerful pumping action. There is very low pressure at the pump’s center (as low as -66,252 Pascals), which sucks blood into the device. The pressure then increases by over 71,000 Pascals by the time the blood reaches the outlet. This large pressure difference is what allows the pump to successfully push blood through the patient’s body.

Figure 3: Velocity and pressure contours from the Centrifugal Blood Pump CFD analysis, showing the flow path and pressure increase.

The wall shear stress (WSS) contour tells us about the safety of the blood flow. This professional visual shows how much the moving blood rubs against the pump’s walls. The highest rubbing forces, up to 489.8 Pascals, happen on the leading edges of the impeller blades where the blood is pushed the hardest. This information is critical for engineers. If the WSS is too high, it can damage blood cells, causing hemolysis. If the flow is too slow in other areas, it can lead to dangerous blood clots. The most important achievement of this simulation is the ability to see the exact relationship between high pumping power and the stress put on the blood, giving engineers the data needed to design a pump that is both strong enough to support a patient and gentle enough to keep their blood safe.

Figure 4: Wall Shear Stress (WSS) contour from the Hemolysis Prediction CFD study, highlighting high-stress areas on the impeller.