Abstract
The separation of a flow through a tube having a local annular constriction was studied experimentally. Empirical expressions for the Reynolds number at which separation occurs and for the length of the separation zone were determined in terms of the flow and of the constriction characteristics. The implications of this phenomenon are discussed in relation to an occlusive vascular stenosis.
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Abbreviations
- L :
-
separation length
- L i :
-
separation length visualized by downstream injection
- L s :
-
separation length visualized by upstream injection
- \(\bar L\) :
-
separation parameter, defined by eq (3)
- R :
-
radius of the tube
- Re :
-
Reynolds number
- Re * :
-
critical Reynolds number for the onset of separation
- V m :
-
mean velocity based on mass flow
- Z :
-
radius of curvature
- \(\bar Z\) :
-
mean radius of curvature defined by eq (5)
- r(x) :
-
section equation of the constriction
- x :
-
axial coordinate
- x i :
-
initial coordinate of the constriction
- x f :
-
final coordinate of the constriction
- α:
-
frequency parameter
- δ:
-
height of the protuberance
- ν:
-
kinematic viscosity
- ω:
-
frequency of the pulsatile flow
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Golia, C., Evans, N.A. Flow separation through annular constrictions in tubes. Experimental Mechanics 13, 157–162 (1973). https://doi.org/10.1007/BF02322669
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DOI: https://doi.org/10.1007/BF02322669