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WANG SHUAI, TAN JIANPING, YU ZHEQIN. COMPARISON AND EXPERIMENTAL VALIDATION OF TURBULENCE MODELS FOR AN AXIAL FLOW BLOOD PUMP. J MECH MED BIOL 2019. [DOI: 10.1142/s0219519419400633] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Computational fluid dynamics (CFD) has become an essential tool for designing and optimizing the structure of blood pumps. However, it is still questionable which turbulence model can better obtain the flow information for axial flow blood pump. In this study, the axial flow blood pump was used as the object, and the influence of the common turbulence models on simulation was compared. Six turbulence models (standard [Formula: see text]–[Formula: see text] model, RNG [Formula: see text]–[Formula: see text] model, standard [Formula: see text]–[Formula: see text] model, SST [Formula: see text]–[Formula: see text] model, Spalart–Allmaras model, SSG Reynolds stress model) were used to simulate the pressure difference and velocity field of the pump. In parallel, we designed a novel drive system of the axial flow blood pump, which allowed the camera to capture the internal flow field. Then we measured the flow field in the impeller region based on particle image velocimetry (PIV). Through the comparison of experiments and simulation results, the average errors of velocity field obtained by the above models are 30.97%, 19.40%, 24.25%, 15.28%, 28.51%, 23.00%, respectively. Since the SST [Formula: see text]–[Formula: see text] model has the smallest error, and the streamline is consistent with the experimental results, it is recommended to use SST [Formula: see text]–[Formula: see text] model for numerical analysis of the axial flow blood pump.
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Affiliation(s)
- SHUAI WANG
- College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, P. R. China
| | - JIANPING TAN
- College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, P. R. China
| | - ZHEQIN YU
- College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, P. R. China
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Hijikata W, Maruyama T, Suzumori Y, Shinshi T. Measuring real-time blood viscosity with a ventricular assist device. Proc Inst Mech Eng H 2019; 233:562-569. [DOI: 10.1177/0954411919838738] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Ventricular assist devices assist in blood circulation and form a crucial component of artificial hearts. While it is important to measure parameters such as the flow rate, pressure head and viscosity of the blood, implanting additional devices to do such measurements is inadvisable. To this end, we demonstrate the adaptation of a ventricular assist device for the purpose of measuring blood viscosity. Such an approach eliminates the need for additional dedicated viscometers in artificial hearts. In the proposed method, the blood viscosity is measured by applying radial vibrational excitation to the impeller in a ventricular assist device using its magnetic levitation system. During the measurement, blood is exposed to a combination of a low shear rate (≈100/s) generated by the radial vibration of the impeller and a high shear rate (>10,000/s) generated by the impeller’s rotation. The apparent viscosity of blood depends on the shear rate, so we determined which shear rate was the dominant one in the proposed method. The measurement results showed that the viscosity measured by the proposed method was in good agreement with the reference viscosity measured with a high shear rate. The mean absolute deviation in the measurements using the proposed method and those obtained using a concentric cylindrical viscometer at a high shear rate was 0.12 mPa s for four samples of porcine blood, with viscosities ranging from 2.32 to 2.75 mPa s.
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Affiliation(s)
- Wataru Hijikata
- School of Engineering, Tokyo Institute of Technology, Tokyo, Japan
| | - Takuro Maruyama
- School of Engineering, Tokyo Institute of Technology, Tokyo, Japan
| | - Yuki Suzumori
- Laboratory for Future Interdisciplinary Research of Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Tadahiko Shinshi
- Laboratory for Future Interdisciplinary Research of Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
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