Numerical simulation of unsteady blood flows in Bi-ventricular Assist Device
Yuan Jianping1, Sun Wenting1, Wang Longyan2, Fu Yanxia1, Hong Feng1, Zhou Banglun1
1.National Research Center of Pumps, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 2.Science and Engineering Faculty, Queensland University of Technology, Brisbane 4000, Australia
Abstract:The unsteady blood flow field in a new type of ventricular assist device, namely the Bi-ventricular Assist Device(BVAD)under the design condition is calculated based on a CFD method. The blood velocity, turbulent kinetic energy and shear stress, mass flow rate in the pump inlets, axial and radial thrusts acted on the different components are obtained; moreover the static pressure fluctua-tion in the volutes is also analyzed. The results show that there are no notable stagnant regions for thrombus formation in the device. The pressure and shear stress are distributed similarly and uniformly in the device, showing an excellent anti-hemolysis performance. Because of the symmetrical structure of the BVAD, the axial force has been basically balanced by itself. The radial force and torque on the impellers are relatively low, showing the device can endure a transient radial load well. The pressure fluctua-tions in the volutes vary periodically, exhibiting six peaks and six valleys in time domain. The dominated frequency at every monitoring point is the blade passing frequency of the device due to the rotor-stator interaction.
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