Hostname: page-component-7479d7b7d-m9pkr Total loading time: 0 Render date: 2024-07-13T10:00:15.853Z Has data issue: false hasContentIssue false

Measurements in a self-preserving plane wall jet in a positive pressure gradient

Published online by Cambridge University Press:  29 March 2006

H. P. A. H. Irwin
Affiliation:
Department of Mechanical Engineering, McGill University, Montreal, Canada

Abstract

Measurements of a wall jet in a self-preserving pressure gradient are described. The quantities measured with a linearized hot-wire anemometer were the mean velocity, the turbulence stresses, triple and quadruple velocity correlations, intermittency and spectra of the longitudinal turbulence intensity. The turbulence, as well as the mean flow, reached a self-preserving state in which the ratio of the maximum velocity to the free-stream velocity was 2·65. Skin friction was also measured using the razor-blade technique in the viscous sublayer and buffer region. The values of the constants in the logarithmic law of the wall are found to be similar to those in boundary-layer and pipe flows. The skin-friction coefficient is slightly lower than that found for the wall jet in still air (Guitton 1970), but close to the formula of Bradshaw & Gee (1962) for the wall jet in an external stream with zero pressure gradient.

A balance of the terms in the turbulence energy equation is presented and discussed. The shearing stress is not zero at the point of maximum velocity but is of opposite sign to that at the wall and hence the contribution of this stress to turbulence production is negative in the outer part of the boundary-layer region. However, the total turbulence production remains positive because the contribution of the normal stresses is positive and slightly larger. The pressure—velocity gradient correlations are evaluated by difference from the Reynolds stress equations and are compared with the theoretical model of Hanjalić & Launder (1972b). Agreement is quite good in the outer region of the wall jet. The above model is also compared with the triple velocity correlations and again found to be in fair agreement.

Type
Research Article
Copyright
© 1973 Cambridge University Press

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

Batchelor, G. K. 1953 The Theory of Homogeneous Turbulence. Cambridge University Press.
Bradbury, L. J. S. 1965 The structure of a self-preserving plane jet. J. Fluid Mech. 23, 31.Google Scholar
Bradshaw, P. 1963 The effect of wind tunnel screens on ‘two-dimensional’ boundary layers. Nat. Phys. Lab. Aero. Rep. no. 1085.Google Scholar
Bradshaw, P. 1967 Conditions for the existence of an inertial subrange in turbulent flow. Nat. Phys. Lab. Aero. Rep. no. 1220.Google Scholar
Bradshaw, P. & Ferriss, D. H. 1965 The spectral energy balance in a turbulence mixing layer. Aero. Res. Counc. Current Paper, no. 899.Google Scholar
Bradshaw, P. & Gee, M. T. 1962 Turbulent wall jets with and without an external stream. Aero. Res. Counc. R. & M. no. 3252.Google Scholar
Champagne, F. H., Harris, V. G. & Corrsin, S. 1970 Experiments in nearly homogeneous turbulent shear flow. J. Fluid Mech. 41, 81.Google Scholar
Champagne, F. H., Sleicher, C. A. & Wehrmann, O. H. 1967 Turbulence measurements with inclined hot wires. Part 1. J. Fluid Mech. 28, 153.Google Scholar
Chou, P. Y. 1945 On velocity correlations and the solutions of the equations of turbulent fluctuation. Quart. Appl. Math. 3, 38.Google Scholar
East, L. F. 1967 Measurement of skin friction at low subsonic speeds by the razor-blade technique. Aero. Res. Counc. R. & M. no. 3525.Google Scholar
Erian, F. & Eskinazi, S. 1964 The wall-jet in a longitudinal pressure gradient. Syracuse University Res. Inst., Mech. & Aerospace Engng Dept. Rep. ME 937–6410F.Google Scholar
Fekete, G. I. 1970 Two-dimensional, self-preserving turbulent jets in streaming flow. Mech. Eng. Res. Lab., McGill University, Rep. no. 70–11.Google Scholar
Foster, D. N., Irwin, H. P. A. H. & Williams, B. R. 1971 The two-dimensional flow around a slotted flap. Aero. Res. Counc. R. & M. no. 3681.Google Scholar
Gartshore, I. S. 1965 The streamwise development of two-dimensional wall-jets and other two-dimensional turbulent shear flows. Ph.D. thesis, McGill University.
Gartshore, I. S. & Hawaleshka, O. 1964 The design of a two-dimensional blowing slot and its application to a turbulent wall jet in still air. Mech. Engng Res. Lab., McGill University, Tech. Note, no. 64–5.Google Scholar
Gartshore, I. S. & Newman, B. G. 1969 Small perturbation jets and wakes which are approximately self-preserving in a pressure gradient. C.A.S.I. Trans. 2, 101.Google Scholar
Grant, H. L., Stewart, R. W. & Moilliet, A. 1962 Turbulence spectra from a tidal channel. J. Fluid Mech. 12, 241.Google Scholar
Guitton, D. E. 1970 Some contributions to the study of equilibrium and non-equilibrium wall jets over curved surfaces. Ph.D. thesis, McGill University.
Hanjalić, K. & Launder, B. E. 1972a Fully developed asymmetric flow in a plane channel. J. Fluid Mech. 51, 301.Google Scholar
Hanjalić, K. & Launder, B. E. 1972b A Reynolds stress model of turbulence and its application to thin shear flows. J. Fluid Mech. 52, 609.Google Scholar
Irwin, H. P. A. H. 1972 The longitudinal cooling correction for wires inclined to the prongs and some turbulence measurements in fully developed pipe flow. Mech. Engng Res. Lab., McGill University, Tech. Note, no. 72–1.Google Scholar
Jerome, F. E., Guitton, D. E. & Patel, R. P. 1971 Experimental study of the thermal wake interference between closely spaced wires of a X-type hot wire. Aero. Quart. 22, 119.Google Scholar
Kacker, S. C. & Whitelaw, J. H. 1969 The turbulence characteristics of two-dimensional wall jet and wall wake flows. Dept. Mech. Engng, Imperial College, Rep. BL/TN/6.Google Scholar
Kruka, V. & Eskinazi, S. 1964 The wall jet in a moving stream. J. Fluid Mech. 20, 555.Google Scholar
MacMillan, F. A. 1956 Experiments on pitot-tubes in shear flow. Aero. Res. Counc. R. & M. no. 3028.Google Scholar
McGahan, W. A. 1965 The incompressible turbulent wall jet in an adverse pressure gradient. Gas Turbine Lab., M.I.T., Rep. no. 82.Google Scholar
Mellor, G. L. & Gibson, D. M. 1966 Equilibrium turbulent boundary layers. J. Fluid Mech. 24, 225.Google Scholar
Newman, B. G. 1967 Turbulent jets and wakes in a pressure gradient. Fluid Mech. Internal Flow, Gen. Motors Conf. Elsevier
Patel, R. P. 1962 Self-preserving, two dimensional turbulent jets and wall jets in a moving stream. M.Sc. thesis, McGill University.
Patel, R. P. 1964 The effects of wind tunnel screens and honeycombs on spanwise variation of skin friction in ‘two-dimensional’ turbulent boundary layers. Mech. Engng Res. Lab., McGill University, Tech. Note, no. 64–7.Google Scholar
Patel, R. P. & Newman, B. G. 1961 Self-preserving, two-dimensional turbulent jets and wall jets in a moving stream. Mech. Engng Res. Lab., McGill University, Rep. Ae 5.Google Scholar
Patel, V. C. 1965 Calibration of the Preston tube and limitations on its use in pressure gradients. J. Fluid Mech. 23, 185.Google Scholar
Pond, S., Stewart, R. W. & Burling, R. W. 1963 Turbulence spectra in the wind over waves. J. Atmos. Sci. 20, 319.Google Scholar
Rotta, J. C. 1951 Statistiche Theorie nichthomogener Turbulenz. Z. Phys. 129, 547.Google Scholar
Rotta, J. C. 1962 Universal aspects of the mechanism of turbulent boundary layer flow. Progr. Aero. Sci. 2, 22.Google Scholar
Tailland, A. & Mathieu, J. 1967 Jet pariétal. J. Mécanique, 6, 103.Google Scholar
Townsend, A. A. 1956a The properties of equilibrium boundary layers. J. Fluid Mech. 1, 561.Google Scholar
Townsend, A. A. 1956b The Structure of Turbulent Shear Flow. Cambridge University Press.
Townsend, A. A. 1961 Equilibrium layers and wall turbulence. J. Fluid Mech. 11, 97.Google Scholar
Vroomen, L. J. 1970 Data logger operating subsystem. Mech. Engng Res. Lab., McGill University, Memo. no. 70–1.Google Scholar
Wills, J. A. B. 1963 Note on a method of measuring skin friction. Nat. Phys. Lab. Aero. Note, no. 1011.Google Scholar
Wygnanski, I. & Fiedler, H. 1969 Some measurements in the self-preserving jet. J. Fluid Mech. 38, 577.Google Scholar
Wygnanski, I. & Gartshore, I. S. 1963 General description and calibration of the McGill 17 in. x 30 in. Blower Cascade Wind Tunnel. Mech. Engng Res. Lab., McGill University, Tech. Note, no. 63–7.Google Scholar
Wyngaard, J. C. 1969 Spatial resolution of the vorticity meter and other hot-wire arrays. J. Sci. Instrum. 2 (2), 983.Google Scholar