Premium
Quantitative Visualization of Flow Through a Centrifugal Blood Pump: Effect of Washout Holes
Author(s) -
Nishida Masahiro,
Yamane Takashi,
Orita Toyoki,
Asztalos Balázs,
Clarke Helen
Publication year - 1997
Publication title -
artificial organs
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.684
H-Index - 76
eISSN - 1525-1594
pISSN - 0160-564X
DOI - 10.1111/j.1525-1594.1997.tb03730.x
Subject(s) - impeller , washout , flow visualization , mechanics , flow (mathematics) , vortex , centrifugal pump , particle image velocimetry , backflow , front (military) , materials science , physics , engineering , mechanical engineering , inlet , turbulence , meteorology
To clarify the effect of washout holes on the flow in a centrifugal blood pump to prevent blood stagnation, a quantitative flow visualization technique was applied to compare flows in models with and without washout holes. A scaled‐up model of a prototype pump and a high speed video camera were used for the flow visualization, and images were processed by particle tracking ve‐locimetry. Particular attention was paid to the flow through the gaps behind and in front of the impeller. The results showed that in the gap behind the impeller, washout holes caused not only an inward flow, but also an increase in the tangential velocities. In the gap in front of the impeller, washout holes caused an outward flow and a decrease in the tangential velocities. Head flow characteristics were little affected by the washout holes in this initial design for which the flow through the washout holes was set to be approximately 10% of the flow in the external circuit. These results suggest that the flow through washout holes is significant in the prevention of blood stagnation in 2 ways. First, the inward radial velocity behind the impeller and outward velocity in front of the impeller result in fluid exchange, and second, a tangential velocity increase reduces fluid stagnation behind the impeller.