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The separating flow through a severely constricted symmetric tube

Published online by Cambridge University Press:  19 April 2006

F. T. Smith
Affiliation:
Department of Mathematics, Imperial College, London

Abstract

The axisymmetric flow of an incompressible fluid through a pipe (of radius a) suffering a severe constriction is studied for large Reynolds numbers R, the features of symmetric channel flows being virtually the same. Here ‘severe’ refers to a constriction whose typical dimensions are finite, and the oncoming velocity profile is taken to be of a realistic type, i.e. with no slip at the wall. The study adopts (Kirchhoff) free-streamline theory, which, for the mostly inviscid description, affords a rational basis consistent with viscous separation. The major (triple-deck) separation takes place on the constriction surface and is followed by a downstream eddy of length O(aR). Another, less familiar, separation is predicted to occur at a distance 0.087a In R + O(a) ahead of the finite obstacle. Free-streamline solutions are found in the two main extremes of moderately severe and very severe constriction. In both extremes, and in any slowly varying constriction, the major separation is sited near the maximum constriction point. The upstream separation point is also derived, to O(a) accuracy in each case. The upstream separation can be suppressed, however, if the constriction has no definite starting point and decaysslowly upstream, but then the upstream flow response extends over a much increased distance. Comparisons with Navier-Stokes solutions and with experiments tend to favour the predictions of the free-streamline theory.

Type
Research Article
Copyright
© 1979 Cambridge University Press

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References

Batchelor, G. K. 1956 On steady laminar flow with closed streamlines at large Reynolds number. J. Fluid Mech. 1, 177.Google Scholar
Batchelor, G. K. 1967 An Introduction to Fluid Dynamics. Cambridge University Press.
Bates, S. 1978 Ph.D. thesis, University of London.
Brodetsky, S. 1923 Discontinuous fluid motion past circular and elliptic cylinders. Proc. Roy. Soc. A 102, 542.Google Scholar
Brown, S. N. & Stewartson, K. 1970 Trailing edge stall. J. Fluid Mech. 42, 561.Google Scholar
Burggraf, O. R. 1970 U.S. Air Force Aerospace Res. Lab. Rep. ARL 70-0275.
Burggraf, O. R. 1975 Asymptotic theory of separation and reattachment of a laminar boundary layer on a compression ramp. AGARD Paper no. 168.Google Scholar
Deshpande, M. D., Giddens, D. P. & Mabon, F. R. 1976 Steady laminar flow through modelled vascular stenoses. J. Biomech. 9, 165.Google Scholar
Föttinger, H. 1939 Mitt. Vereinigung Gross-Kesselbesitzer no. 73, p. 151.
Fraenkel, L. D. 1961 On corner eddies in plane inviscid shear flow. J. Fluid Mech. 11, 400.Google Scholar
Friedman, M. 1972 Laminar flow in a channel with a step. J. Engng Math. 6, 285.Google Scholar
Goldstein, S. 1948 On laminar boundary layer flow near a point of separation. Quart. J. Mech. Appl. Math. 1, 43.Google Scholar
Greenspan, D. 1969 Numerical studies of steady, viscous, incompressible flow in a channel with a step. J. Engng Math. 3, 21.Google Scholar
Grove, A. S., Shair, F. H., Petersen, E. E. & Acrivos, A. 1964 An experimental investigation of the steady separated flow past a circular cylinder. J. Fluid Mech. 19, 60.Google Scholar
Hall, P. & Parker, K. H. 1976 The stability of the decaying flow in a suddenly blocked channel. J. Fluid Mech. 75, 305.Google Scholar
Hung, T.-K. & Macagno, E. O. 1966 Laminar eddies in a two-dimensional conduit expansion. Houille Blanche 21, 391.Google Scholar
Jenson, R., Burggraf, O. R. & Rizzetta, D. P. 1974 Asymptotic solution for supersonic viscous flow past a compression corner. Proc. 4th Int. Conf. Num. Meth. Fluid Mech., p. 218. Springer.
Jones, C. W. & Watson, E. J. 1963 In Laminar Boundary Layers (ed. L. Rosenhead), chap. 5. Oxford University Press.
Kirchhoff, G. 1869 Zur Theorie freier Flussigkeitsstrahlen. J. reine angew. Math. 70, 289.Google Scholar
Lee, J.-S. & Fung, J. L. 1970 Flow in locally constricted tubes at low Reynolds numbers. J. Appl. Mech. 37, 9.Google Scholar
Lee, J.-S. & Fung, J. L. 1971 Flow in non-uniform small blood vessels. Microvasc. Res. 3, 272.Google Scholar
Lock, R. C. 1951 The velocity distribution in the laminar boundary layer between parallel streams. Quart. J. Mech. 4, 42.Google Scholar
Macagno, E. O. & Hung, T.-K. 1967 Computational and experimental study of a captive annular eddy. J. Fluid Mech. 28, 43.Google Scholar
Melnik, R. E. & Chow, R. 1975 Asymptotic theory of two-dimensional trailing edge flows. Grumman Res. Rep. RE-510J.Google Scholar
Messiter, A. F., Hough, G. R. & Feo, A. 1973 Base pressure in laminar supersonic flow. J. Fluid Mech. 60, 605.Google Scholar
Milne-thompson, L. M. 1968 Theoretical Hydrodynamics, 5th edn. Macmillan.
Roshko, A. 1967 A review of concepts in separated flow. Proc. Can. Congr. Appl. Mech., Quebec, vol. 3, p. 81.
Smith, F. T. 1976a Flow through constricted or dilated pipes and channels. Quart. J. Mech. Appl. Math. 29, 343.Google Scholar
Smith, F. T. 1976b Flow through constricted or dilated pipes and channels. Part 2. Quart. J. Mech. Appl. Math. 29, 365.Google Scholar
Smith, F. T. 1976c Pipeflows distorted by nonsymmetric indentation or branching. Mathe-matika 23, 62.Google Scholar
Smith, F. T. 1976d On entry-flow effects in bifurcating, blocked or constricted tubes. J. Fluid Mech. 78, 709.Google Scholar
Smith, F. T. 1977a Flow through symmetrically constricted tubes. J. Inst. Math. Appl. 21, 145.Google Scholar
Smith, F. T. 1977b The laminar separation of an incompressible fluid streaming past a smooth surface. Proc. Roy. Soc. A 356, 443.Google Scholar
Smith, F. T. 1977c Upstream interactions in channel flows. J. Fluid Mech. 79, 631.Google Scholar
Smith, F. T. & Duck, P. W. 1977 Separation of jets or thermal boundary layers from a wall. Quart. J. Mech. Appl. Math. 30, 143.Google Scholar
Sobey, I. J. 1976 Inviscid secondary motions in a tube of slowly varying ellipticity. J. Fluid Mech. 73, 621.Google Scholar
Stewartson, K. 1970a Is the singularity at separation removable? J. Fluid Mech. 44, 347.Google Scholar
Stewartson, K. 1970b On supersonic laminar boundary layers near convex corners. Proc. Roy. Soc. A 319, 289.Google Scholar
Stewartson, K. 1974 Multistructured boundary layers on flat plates and related bodies. Adv. Appl. Mech. 14, 145.Google Scholar
Stewartson, K. & Williams, P. G. 1973 Self-induced separation II. Mathematika 20, 98.Google Scholar
Sychev, V. Ya. 1972 Concerning laminar separation. Izv. Akad. Nauk SSSR, Mekh. Zh. Gaza 3, 47.Google Scholar
Tillett, J. P. K. 1968 On the laminar flow in a free jet of liquid at high Reynolds number. J. Fluid Mech. 32, 273.Google Scholar
Woods, L. C. 1955 Two-dimensional flow of a compressible fluid past given curved obstacles with infinite wakes. Proc. Roy. Soc. A 227, 367.Google Scholar
Yih, C.-S. 1959 Two solutions for inviscid rotational flow with corner eddies. J. Fluid Mech. 5, 36.Google Scholar
Yih, C.-S. 1960 Exact solutions for steady two-dimensional flow of a stratified fluid. J. Fluid Mech. 9, 161.Google Scholar
Young, D. F. & Tsai, F. Y. 1973 Flow characteristics in models of arterial stenoses I. Steady flow. J. Biomech. 6, 395.Google Scholar