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Internal Hydraulic Loss in a Seal‐less Centrifugal Gyro Pump
Author(s) -
Makinouchi Kenzo,
Ohara Yasuhisa,
Sakuma Ichiro,
Damm George,
Mizuguchi Kazumi,
Jikuya Tomoaki,
Takatani Setsuo,
Noon George P.,
Nosé Yukihiko
Publication year - 1994
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.1525-1594.1994.tb03295.x
Subject(s) - mechanics , centrifugal pump , casing , control theory (sociology) , hydraulic pump , sensitivity (control systems) , friction loss , rotor (electric) , progressive cavity pump , rotodynamic pump , mathematics , flow (mathematics) , loop (graph theory) , physics , reciprocating pump , variable displacement pump , engineering , mechanical engineering , thermodynamics , computer science , control (management) , combinatorics , artificial intelligence , electronic engineering , impeller
A new index “loss factor Z” defined by Eq. 1 was introduced as the absolute expression of the mock loop resistance for testing a nonpulsatile pump. Z = 2 g /γΔ P / Q 2 (1) where γ is specific gravity of the fluid, g is the acceleration of gravity, Δ P is total pressure head, and Q is flow. Z is expected to be constant, regardless of the pumping parameters. Z values obtained in the same mock loop but with different rotary blood pumps were almost identical and were defined as Z 0 . New methods of analysis of the flow‐restrictive conditions of various rotary blood pumps are proposed in this paper: namely, differential loss factor Δ Z , and loss factor sensitivity ∂ Z /∂ A. The proposed Z‐Q curves demonstrated better performance mapping than the conventional Δ P‐Q curves. Δ Z is the difference between the Z‐Q curves of two different pumps. A is a design parameter of the pump; therefore ∂ Z /∂ A is a quantitative expression of the effect of the design change on the hydraulic performance. These various indices were used to analyze the internal hydraulic loss of a centrifugal pump (Gyro pump). The relationship between its gap size (rotor casing) and hydraulic performance was assessed quantitatively by these indices. In this paper, the derivation processes and above‐mentioned indices are described.