Hostname: page-component-7c8c6479df-xxrs7 Total loading time: 0 Render date: 2024-03-29T09:26:02.715Z Has data issue: false hasContentIssue false

Global density effects on the self-preservation behaviour of turbulent free jets

Published online by Cambridge University Press:  26 April 2006

C. D. Richards
Affiliation:
National Institute of Standards and Technology, Building and Fire Research Laboratory, Gaithersburg, MD 20899, USA Current address: Department of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164-2920, USA.

Abstract

An experimental investigation was designed to test the hypothesis that all axisymmetric turbulent free jets become asymptotically independent of the source conditions and may be described by classical similarity analysis. Effects of initial conditions were studied by varying jet exit boundary conditions and the global density ratio. The exit velocity profile and turbulence level was changed by using both pipe and nozzle flow hardware. Initial density differences were imposed by using three gases: helium, methane, and propane. The scalar field (concentration) in the momentum-dominated regime of the far field (10 to 60 jet exit diameters downstream) of turbulent free jets was characterized using Rayleigh light scattering as the diagnostic. The results show that regardless of the initial conditions axisymmetric turbulent free jets decay at the same rate, spread at the same angle, and both the mean and r.m.s. values collapse in a form consistent with full self-preservation. The means and fluctuations follow a law of full self-preservation in which two virtual origins must be specified. The two displacements are required to account for the effects of a finite source of momentum and different development of the velocity and mass distributions in the near fields of the jets. The memory of the jet is embodied in these two virtual origins.

Type
Research Article
Copyright
© 1993 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

Abramovich, G. N. 1963 The Theory of Turbulent Jets. MIT Press.
Avery, J. F. & Faeth, G. M. 1975 Combustion of a submerged gaseous oxidizer jet in a liquid metal. Fifteenth (Intl) Symp. Combust., pp. 501512. The Combustion Institute.
Becker, H. A., Hottel, H. C. & Williams, G. C. 1967 The nozzle-fluid concentration field of the round, turbulent, free jet. J. Fluid Mech. 30, 285303.Google Scholar
Birch, A. D., Brown, D. R., Dodson, M. G. & Thomas, J. R. 1978 The turbulent concentration field of a methane jet. J. Fluid Mech. 88, 431449.Google Scholar
Browne, L. W. B., Antonia, R. A. & Chambers, A. J. 1984 The interaction region of a turbulent plane jet. J. Fluid Mech. 149, 355373.Google Scholar
Browne, L. W. B., Antonia, R. A., Rajagopanan, S. & Chambers, A. J. 1983 Interaction region of a two-dimensional turbulent plane jet in still air. In Structure of Complex Turbulent Shear Flow (ed. R. Dumas & L. Fulachier), pp. 411419. Springer.
Bryner, N., Richards, C. D. & Pitts, W. M. 1992 A Rayleigh light scattering facility for the investigation of free jets and plumes. Rev. Sci. Instrum. 63, 36293635.Google Scholar
Chambers, F. W. & Goldschmidt, V. W. 1982 Acoustic interaction with a turbulent plane jet: effects on mean flow. AIAA J. 20, 797804.Google Scholar
Chen, C. J. & Rodi, W. 1980 Vertical Turbulent Buoyant Jets – A Review of Experimental Data. Pergamon.
Dahm, W. J. A. & Dibble, R. W. 1988 Coflowing turbulent jet diffusion flame blowout. Twenty-Second (Intl) Symp. Combust., pp. 801808. The Combustion Institute.
Dahm, W. A. & Dimotakis, P. E. 1987 Measurements of entrainment and mixing in turbulent jets. AIAA J. 25, 12161223.Google Scholar
Dowling, D. R. 1991 The estimated scalar dissipation rate in gas-phase turbulent jets. Phys. Fluids A 3, 22292246.Google Scholar
Dowling, D. R. & Dimotakis, P. E. 1988 On mixing and structure of the concentration field of turbulent jets. In Proc. First National Congress on Fluid Dynamics, 25–28 July 1988 Cincinnati, Ohio. Part 2, pp. 982988. New York: AIAA.
Dowling, D. R. & Dimotakis, P. E. 1990 Similarity of the concentration field of gas-phase turbulent jets. J. Fluid Mech. 218, 109141.Google Scholar
Fischer, H. B., List, E. J., Koh, R. C. Y., Imberger, J. & Brooks, N. H. 1979 Mixing in Inland and Coastal Waters. Academic.
Flora, J. J. & Goldschmidt, V. W. 1969 Virtual origins of a free plane turbulent jet. AIAA J. 7, 23442346.Google Scholar
Gouldin, F. C., Schefer, R. W., Johnson, S. C. & Kollmann, W. 1986 Nonreacting turbulent mixing flows. Prog. Energy Combust. Sci. 12, 257303.Google Scholar
Grandmaison, E. W., Rathgeber, D. E. & Becker, H. A. 1982 Some characteristics of concentration fluctuations in free turbulent jets. Can. J. Chem. Engng 60, 212219.Google Scholar
Harsha, P. T. 1971 Free turbulent mixing: a critical evaluation of theory and experiment. Arnold Engineering Development Center Rep. AEDC-TR-71-36.
Hawthorne, W. R., Weddell, D. S. & Hottel, H. C. 1949 Mixing and combustion in turbulent gas jets. Third (Intl) Symp. Combust., pp. 266288. The Combustion Institute.
Hinze, J. O. 1975 Turbulence, 2nd Edn. McGraw-Hill.
Hinze, J. O. & Hegge Zijnen, B. G. van der 1947 Transfer of heat and matter in the turbulent mixing zone of an axially symmetrical jet. Appl. Sci. Res. A 1, 435461.Google Scholar
Hussain, A. K. M. F. & Clark, A. R. 1977 Upstream influence on the near field of a plane turbulent jet. Phys. Fluids 20, 14161426.Google Scholar
LaRue, J. C., Libby, P. A. & Seshadri, V. R. 1981 Further results on the thermal mixing layer downstream of a turbulence grid. Phys. Fluids 24, 19271933.Google Scholar
Morton, B. R., Taylor, G. I. & Turner, J. S. 1956 Turbulent gravitational convection from maintained and instantaneous sources. Proc. R. Soc. Lond. 234, 123.Google Scholar
Namazian, M., Schefer, R. W. & Kelly, J. 1988 Scalar dissipation measurements in the developing region of a jet. Combust. Flame 74, 147160.Google Scholar
Niwa, C., Ichizawa, J., Yoshikawa, N. & Ohtake, K. 1984 Time-resolved concentration measurements of jets by laser Rayleigh method-comparison of He, CO2, and CCl2F2 jets. Proc. Fourteenth Intl Symp. Space Tech. and Science, Tokyo, pp. 469476.
Papanicolaou, P. N. & List, E. J. 1988 Investigations of round vertical turbulent buoyant jets. J. Fluid Mech. 195, 341391.Google Scholar
Pitts, W. M. 1991a Effects of global density ratio on the centerline mixing behavior of axisymmetric turbulent jets. Expts Fluids 11, 125134.Google Scholar
Pitts, W. M. 1991b Reynolds number effects on the centerline mixing behavior of axisymmetric turbulent jets. Expts Fluids 11, 135144.Google Scholar
Pitts, W. M. & Kashiwagi, T. 1984 The application of laser-induced Rayleigh light scattering to the study of turbulent mixing. J. Fluid Mech. 141, 391429.Google Scholar
Schefer, R. W. & Dibble, R. W. 1986 Mixture fraction measurements in a turbulent nonreacting propane jet. AIAA Paper 86-0278.
Schlichting, H. 1979 Boundary Layer Theory, 7th edn. McGraw-Hill.
Sforza, P. M. & Mons, R. F. 1978 Mass, momentum, and energy transport in turbulent free jets. Intl J. Heat Mass Transfer 21, 371384.Google Scholar
So, R. M. C. & Lui, T. M. 1986 On self-preserving, variable-density, turbulent free jets. Z. Angew. Math. Phys. 37, 538558.Google Scholar
So, R. M. C., Zhu, J. Y. Z., Otugen, M. V. & Huang, B. C. 1990 Some measurements in a binary gas jet. Expts Fluids 9, 273284.Google Scholar
Sunavala, P. D., Hulse, C. & Thring, M. W. 1957 Mixing and combustion in free and enclosed turbulent jet diffusion flames. Combust. Flame 1, 179193.Google Scholar
Thring, M. W. & Newby, M. P. 1953 Combustion length of enclosed turbulent jet flames. Fourth (Intl) Symp. Combust., pp. 789796. The Williams & Wilkins Co.
Townsend, A. A. 1976 The Structure of Turbulent Shear Flow, 2nd edn. Cambridge University Press.
White, F. M. 1974 Viscous Fluid Flow. McGraw-Hill.
Wilson, R. A. M. & Danckwerts, P. V. 1964 Studies in turbulent mixing – II a hot jet. Chem. Engng Sci. 19, 885895.Google Scholar