Summary
Single-point hot-wire measurements have been made in the developing regions of a plane and an unstably curved single-stream mixing layer. In each case the high-velocity potential flow was constrained by a solid surface to form a thick wall jet. The mean flow in the plane layer had reached approximate self-similarity before the turbulent region reached the surface at a point corresponding to the maximum length Reynolds number of 106 but turbulence quantities, particularly the individual normal stresses, were still changing appreciably with downstream distance. The curved mixing layer created by a convex surface had a spreading rate 9% greater than that of the plane flow with increases of 14% in the maximum level of shear stress.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
Abbreviations
- n :
-
distance measured from and normal to the curved layer centreline
- P :
-
total pressure
- Pa :
-
atmospheric pressure
- \(\overline {q^2 } \) :
-
\(\overline {u^2 } + \overline {v^2 } + \overline {w^2 } \)
- R :
-
radius of curved layer centreline
- r :
-
local radius of curvature ≌ R + n
- Re x :
-
length Reynolds number U 0 x/v
- R f :
-
curvature Richardson number defined by Eq. 1
- S :
-
rate of strain ratio defined by Eq. 2
- s :
-
distance measured from the slot along the curved layer centreline
- U0 :
-
mean velocity in the plane of the slot
- u, v, w :
-
fluctuating velocity components in the s, n and z directions
- u′:
-
r.m.s. turbulence intensity
- V :
-
mean velocity in y direction
- x, y :
-
Cartesian co-ordinates, origin at the slot lip
- z :
-
co-ordinate normal to the s-n, x -y, planes
- σ:
-
shear layer thickness defined in text
- σ′:
-
alternative shear layer thickness defined in text
- 0:
-
angle subtended at the centre of curvature of the plane wall
- v :
-
kinematic viscosity
References
Birch, S. F. 1980: Planar mixing layer data evaluation for AFSOR-HTTM-Stanford Conference on Complex Turbulent Flows
Bradshaw, P. 1966: The effect of initial conditions on the development of a free shear layer. J. Fluid Mech. 26, 225–236
Bradshaw, P. 1973: Effect of streamwise curvature on turbulent flows. AGARDograph 169
Bradshaw, P.; Ferris, D. H.; Johnson, R. F. 1964: Turbulence in the noise producing region of a circular jet. J. Fluid Mech. 19, 591–624
Castro, I. P. 1973: A highly distorted turbulent free shear layer. London: Ph.D. thesis, Imperial College
Castro, I. P.; Bradshaw, P. 1976: The turbulence structure of a highly curved mixing layer. J. Fluid Mech. 73, 265–304
Gibson, M. M.; Rodi, W. 1981: A Reynolds-stress closure model of turbulence applied to the calculation of a highly curved mixing layer. J. Fluid Mech. 103, 161–182
Gibson, M. M.; Younis, B. A. 1981: Calculation of a turbulent wall jet on a curved wall with a Reynolds stress model of turbulence. Proc. 3rd Turbulent Shear Flows Symposium 4, 1–6
Gibson, M. M.; Jones, W. P.; Younis, B. A. 1981: Calculation of turbulent boundary layers on curved surfaces. Phys. Fluids 24, 386–395
Gillis, J. C.; Johnston, J. P. 1980: Experiments on the turbulent boundary layer over convex walls and its recovery to flat-wall conditions. Turbulent Shear Flows 2, 116–128, Berlin, Heidelberg, New York: Springer
Goldschmidt, V. W.; Bradshaw, P. 1973: Flapping of a plane jet. Phys. Fluids 16, 354–355
Laker, J. R.; Verriopoulos, C. A.; Vlachos, N. S. 1981: A microprocessor controlled signal acquisition and processing system for hot-wire anemometry. Proc. 7th Biennial Symposium on Turbulence, Rolla-Missouri
Margolis, D. P.; Lumley, J. L. 1965: Curved mixing layer. Phys. Fluids 8, 1775–1784
Meroney, R. N.; Bradshaw, P. 1975: Turbulent boundary layer growth over a longitudinally curved surface. AIAA J. 13, 1448–1453
Rodi, W. 1975: A review of experimental data of uniform density free turbulent boundary layers. In: studies in convection (ed. Launder, B. E.). Vol. 1, pp. 79–166, London: Academic Press
Smits, A. J.; Young, S. T. B.; Bradshaw, P. 1979: The effect of short regions of high surface curvature on turbulent boundary layers. J. Fluid Mech. 94, 209–242
So, R. M. C.; Mellor, G. L. 1973: Experiment on convex curvature effects in turbulent boundary layers. J. Fluid Mech. 60, 43–62
So, R. M. C.; Mellor, G. L. 1975: Experiment on turbulent boundary layers on a curved wall. Aero. Quart. 26, 25–40
Weir, A. D.; Bradshaw, P. 1974: Apparatus and programs for digital analysis of fluctuating quantities in turbulent flow. Imperial College Aero. Rept. 74-09
Wood, D. H.; Bradshaw, P. 1982: A turbulent mixing layer constrained by a solid surface Part l. Measurements before reaching the surface. J. Fluid Mech. 122, 57–89
Wyngaard, J. C.; Tennekes, H.; Lumley, J. L.; Margolis, D. P. 1968: Structure of turbulence in a curved mixing layer. Phys. Fluids 11, 1251–1253
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Gibson, M.M., Younis, B.A. Turbulence measurements in a developing mixing layer with mild destabilising curvature. Experiments in Fluids 1, 23–30 (1983). https://doi.org/10.1007/BF00282263
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00282263