Hostname: page-component-77c89778f8-n9wrp Total loading time: 0 Render date: 2024-07-23T01:59:42.160Z Has data issue: false hasContentIssue false

Scaling and instability of a junction vortex

Published online by Cambridge University Press:  15 February 2007

J. J. ALLEN
Affiliation:
Department of Mechanical Engineering, New Mexico State University, Las Cruces, NM 88003, USA
T. NAITOH
Affiliation:
Department of Systems Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 446, Japan

Abstract

This paper details experiments in the region where an impulsively started moving wall slides under a stationary wall. The experiments were conducted over a Reynolds number range of ReΓ=5×102–5×105. The length scale for the Reynolds number is defined as the distance the wall has moved from rest and increases during an experiment. Experiments show that for ReΓ>103 a vortex forms close to the junction where the moving wall meets the stationary one. The data shows that while the vortical structure is small, in relation to the fixed-apparatus length scale, the size of the vortex normalized with respect to the wall speed and viscosity scales in a universal fashion with respect to ReΓ. The scaling rate is proportional to t5/6 when the Reynolds number is large. The kinematic behaviour of the vortex is related to the impulse that the moving wall applies to the fluid and results in a prediction that the transient structure should grow as t5/6 and the velocity field should scale as t−1/6. The spatial-growth prediction is in good agreement with the experimental results and the velocity scaling is moderately successful in collapsing the experimental data.

For ReΓ>2×104 three-dimensional instabilities appear on the perimeter of the vortical structure and the flow transitions from an unsteady two-dimensional flow to a strongly three-dimensional vortical structure at ReΓ≃ 4 × 104. The instability mechanism is centrifugal. The formation and growth of these instability structures and their ingestion into the primary vortex core causes the three-dimensional breakdown of the primary vortex. Two movies are available with the online version of the paper.

Type
Papers
Copyright
Copyright © Cambridge University Press 2007

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Aidun, C. K., Triantafillopoulos, N. G. & Benson, J. D. 1991 Global stability of a lid driven cavity with throughflow:Flow visualization studies. Phys. Fluids 3, 2018.CrossRefGoogle Scholar
Albensoeder, S., Kuhlmann, H. C. & Rath, H. J. 2001 Three-dimensional centrifugal-flow instabilities in the lid-driven-cavity problem. Phys. Fluids 13, 121135.CrossRefGoogle Scholar
Albensoeder, S. & Kuhlmann, H. C. 2002 Linear stability of rectangular cavity flows driven by anti-parallel motion of two facing walls. J. Fluid Mech. 458, 153180.CrossRefGoogle Scholar
Allen, J. J. & Auvity, B. 2002 Interaction of a vortex ring with a piston vortex. J. Fluid Mech. 465, 453–378.CrossRefGoogle Scholar
Allen, J. J. & Chong, M. S. 2000 Vortex formation in front of a piston moving through a cylinder. J. Fluid Mech. 416, 128.CrossRefGoogle Scholar
Allen, J. J. & Smits, A. J. 2001 Energy harvesting eel. J. Fluids Struct. 15, 629640.CrossRefGoogle Scholar
Bajura, R. A. & Catalano, M. R. 1975 Transition in a two-dimensional plane wall jet. J. Fluid Mech. 70, 773799.CrossRefGoogle Scholar
Bippes, H. 1978 Experimental study of the Laminar-Turbulent transition on a concave wall in a parallel flow. Tech. Rep. NASA TM 75243.Google Scholar
Blackburn, H. M. & Lopez, J. M. 2003 The onset of three-dimensional standing and modulated travelling waves in a periodically driven cavity flow. J. Fluid Mech. 497, 289317.CrossRefGoogle Scholar
Cantwell, B. J. 1986 Viscous starting jets J. Fluid Mech. 173, 159189.CrossRefGoogle Scholar
Cantwell, B., Coles, D. & Dimotakis, P. 1978 Structure and entrainment in the plane of symmetry of a turbulent spot. J. Fluid Mech. 87, 641672.CrossRefGoogle Scholar
Conlon, B. P. & Lichter, S. 1995 Dipole formation in the transient planar wall jet. Phys. Fluids 7, 9991014.CrossRefGoogle Scholar
Floryan, J. M. 1986 Görtler Instability of boundary layers over concave and convex walls. Phys. Fluids 29, 23802387.CrossRefGoogle Scholar
Floryan, J. M. & Saric, W. S. 1984 Wavelength selection of Görtler vortices. AIAA J. 22, 11, 15291538.CrossRefGoogle Scholar
Glauert, M. B. 1956 The wall jet. J. Fluid Mech. 1, 625643.CrossRefGoogle Scholar
Glezer, A. & Coles, D. 1990 An experimental strudy of a turbulent vortex ring. J. Fluid Mech. 211, 243283.CrossRefGoogle Scholar
Guezet, J. & Kageyama, T. 1997 Aerodynamic study in a rapid compression machine. Revue Generale de Thermique 36 (1), 1725. Elsevier.CrossRefGoogle Scholar
Hancock, C., Lewis, E. & Moffatt, H. K. 1981 Effects of inertia in forved corner flows. J. Fluid Mech. 112, 315327.CrossRefGoogle Scholar
Hughes, M. D. & Gerrard, J. H. 1971 The stability of unsteady axisymetric incompressible pipe flow close to a pison. Part 2. Experimental investigation and comparison with computation. J. Fluid Mech. 50, 645655.CrossRefGoogle Scholar
Koseff, J. R. & Street, R. L. 1984 a Visualization studies of a shear driven three-dimensional recirculating flow. Trans. ASME: J. Fluids Engng 106, 21.Google Scholar
Koseff, J. R. & Street, R. L. 1984 b The lid-driven cavity flow: A synthesis of qualitative and quantitative observations. Trans. ASME: J. Fluids Engng 106, 391.Google Scholar
Obokata, T. & Okajima, A. 1992 Roll-up vortex on the reciprocating piston in a cylinder. Sixth Intl Symp. On flow Visualization (ed. Tanida, Y. & Miyashiro, H.), pp. 594598. Springer.CrossRefGoogle Scholar
Pan, F. & Acrivos, A. 1967 Steady flow in rectangular cavities. J. Fluid Mech. 28, 643655.CrossRefGoogle Scholar
Stern, M. E. & Pratt, L. J. 1985 Dynamics of vorticity fronts. J. Fluid Mech. 161, 513532.CrossRefGoogle Scholar
Tabaczynski, R. J., Hoult, D. P. & Keck, J. C. 1970 High Reynolds number flow in a moving corner. J. Fluid Mech. 42, 249255.CrossRefGoogle Scholar
Taylor, G. I. 1960 Aeronautics and Aeromechanics. Pergamon.Google Scholar
Vogel, M. J., Hirsa, A. H & Lopez, J. M. 2003 Spatio-temporal dynamics of a periodically driven cavity flow. J. Fluid Mech. 478, 197226.CrossRefGoogle Scholar