Computational Fluid Dynamics Investigation of a Centrifugal Blood Pump *†Daniel Legendre, *Pedro Antunes, *‡Eduardo Bock, *§Aron Andrade, *José F. Biscegli, and †Jayme Pinto Ortiz *Institute Dante Pazzanese of Cardiology; †Department of Mechanical Engineering, Escola Politécnica, University of São Paulo; ‡University of Campinas; and §University Sao Judas Tadeu, São Paulo, SP, Brazil Abstract: In the development of a ventricular assist device, computational fluid dynamics (CFD) analysis is an efficient tool to obtain the best design before making the final prototype. In this study, different designs of a centrifugal blood pump were developed to investigate flow character- istics and performance. This study assumed the blood flow as being an incompressible homogeneous Newtonian fluid. A constant velocity was applied at the inlet; no slip bound- ary conditions were applied at device wall; and pressure boundary conditions were applied at the outlet. The CFD code used in this work was based on the finite volume method. In the future, the results of CFD analysis can be compared with flow visualization and hemolysis tests. Key Words: Centrifugal blood pump—Hemodynamic— Numerical simulation—Wall shear stress. The Department of Bioengineering of the Institute Dante Pazzanese of Cardiology is developing a new model of continuous flow centrifugal pump in order to address the need for circulatory support in patients with heart failure. In this work, a numerical simulation of a centrifugal blood pump is performed and the results will help our group to improve the design of this device before making a final prototype. The endurance test and hemolysis evaluation of this pro- totype will be carried out at Baylor College of Medi- cine laboratories.In vitro tests allow the verification of some variables without the device implantation (1). This device consists of a magnetically suspended rotor, which means contact-free magnetic support of the rotor that pumps blood. This type of pump does not contain valves and flexing parts that could degrade and/or fail. The main objective of computational fluid dynam- ics (CFD) analysis is to obtain relevant information about the device before making a final prototype. It can help to achieve an efficient hydrodynamic perfor- mance for this device by changing the geometry of the inlet diameter of this pump and performing the numerical simulation in order to choose the design that best fits. CFD evaluation is used not only to achieve the best hydrodynamic performance but also to predict some adverse factors, such as regions and situations of thrombus formation and blood damage (2,3). Those problems can be evaluated by CFD analysis in terms of exposure time of the blood cell, shear stress exerted on it, local acceleration, and region of blood recirculation. MATERIALS AND METHODS CFD analysis The three-dimensional (3-D) CFD geometry model was generated using a 3-D computer aided design software package (Autocad v2005, Autodesk, Inc., San Rafael, CA, USA) (Fig. 1). The computational domain comprises the inlet, the magnetically suspended rotor, gaps that separate the rotor from the stationary housing wall, and the outlet. An unstructured CFD mesh was generated in a grid doi:10.1111/j.1525-1594.2008.00552.x Received September 2007. Address correspondence and reprint requests to Dr. Daniel Leg- endre, Department of Mechanical Engeneering, Escola Politéc- nica, University of São Paulo.Av. Prof. Luciano Gualberto, 380, trav. 3, 05508-900, São Paulo, S.P., Brazil. E-mail: daniel.legendre@ poli.usp.br Presented in part at the 4th Latin American Congress for Arti- ficial Organs and Biomaterials held on August 8–11, 2006, in Caxambú, Brazil. Artificial Organs 32(4):342–348, Blackwell Publishing, Inc. © 2008, Copyright the Authors Journal compilation © 2008, International Center for Artificial Organs and Transplantation and Blackwell Publishing 342