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Updated: Apr 16, 2026
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Modeling and Experimental Analysis of the Single-Shaft Coaxial Motor-Pump Assembly in Electrohydrostatic Actuators
Published on: June 13, 2022
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Hydrodynamic characteristics of the helical flow pump
Kohei Ishii1, Kyohei Hosoda, Masahiro Nishida
1Department of Biomedical Engineering, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan, ishii@bme.gr.jp.
Summary
The helical flow pump (HFP) has unique hydrodynamic characteristics, including vortexes and shunt flow, crucial for its function in total artificial hearts (TAH). Further design improvements can optimize performance and reduce negative pressure.
Area of Science:
- Biomedical Engineering
- Fluid Dynamics
- Medical Devices
Background:
- The helical flow pump (HFP) is a novel technology for total artificial hearts (TAH).
- Hydrodynamic characteristics of the HFP are not fully understood.
- The helical flow total artificial heart (HFTAH) utilizes two HFPs.
Purpose of the Study:
- To analyze the hydrodynamic characteristics of the helical flow pump (HFP).
- To investigate flow velocity, shear stress, and pressure distributions within the HFP.
- To understand the working principle of the HFP for potential improvements.
Main Methods:
- Flow visualization using particle image velocimetry (PIV).
- Computational fluid dynamics (CFD) analysis.
- Development of experimental and computational models simulating the HFP.
Main Results:
- Observed vortexes in the vane, indicating a unique working principle involving centrifugal force and helical fluid transfer.
- Identified high shear stress near the inlet helical volute due to shunt flow, but below levels causing hemolysis.
- Detected negative pressure near the inlet helical volute, deemed not critically high.
Conclusions:
- The HFP operates via a unique principle of centrifugal force rotating fluid within helical volutes.
- Shunt flow and negative pressure present opportunities for design optimization of the HFP.
- Redesigning inlet/outlet volutes and impeller/vane shape can enhance HFP performance and safety.
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