Hostname: page-component-5c6d5d7d68-ckgrl Total loading time: 0 Render date: 2024-08-16T05:04:28.541Z Has data issue: false hasContentIssue false
  • English
  • Français

Experiments on a round turbulent buoyant plume

Published online by Cambridge University Press:  26 April 2006

Aamir Shabbir  and
William K. George
Aamir Shabbir
Affiliation:
Department of Mechanical and Aerospace Engineering, State University of New York at Buffalo, Buffalo, NY 14260, USA Present address: Center for Modeling of Turbulence and Transition, Institute for Computational Mechanics in Propulsion, NASA Lewis Research Center, Cleveland, OH 44135, USA.
William K. George
Affiliation:
Department of Mechanical and Aerospace Engineering, State University of New York at Buffalo, Buffalo, NY 14260, USA
Get access Rights & Permissions [Opens in a new window]

Abstract

This paper reports a comprehensive set of hot-wire measurements of a round buoyant plume which was generated by forcing a jet of hot air vertically up into a quiescent environment. The boundary conditions of the experiment were measured, and are documented in the present paper in an attempt to sort out the contradictory mean flow results from the earlier studies. The ambient temperature was monitored to ensure that the facility was not stratified and that the experiment was conducted in a neutral environment. The axisymmetry of the flow was checked by using a planar array of sixteen thermocouples and the mean temperature measurements from these are used to supplement the hot-wire measurements. The source flow conditions were measured to ascertain the rate at which the buoyancy was added to the flow. The measurements conserve buoyancy within 10%. The results are used to determine balances of the mean energy and momentum differential equations. In the mean energy equation it is found that the vertical advection of energy is primarily balanced by the radial turbulent transport. In the mean momentum equation the vertical advection of momentum and the buoyancy force balance the radial turbulent transport. The buoyancy force is the second largest term in this balance and is responsible for the wider (and higher) velocity profiles in plumes as compared to jets. Budgets of the temperature variance and turbulent kinetic energy are also determined in which thermal and mechanical dissipation rates are obtained as the closing terms. Similarities and differences between the two balances are discussed. It is found that even though the direct effect of buoyancy in turbulence, as evidenced by the buoyancy production term, is substantial, most of the turbulence is produced by shear. This is in contrast to the mean velocity field where the effect of the buoyancy force is quite strong. Therefore, it is concluded that in a buoyant plume the primary effect of buoyancy on turbulence is indirect, and enters through the mean velocity field (giving larger shear production).

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 275 , 25 September 1994 , pp. 1 - 32
Copyright
© 1994 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

Baker, C. B., Taulbee, D. B. & George, W. K. 1980 An analysis of buoyant jet heat transfer. Proc. 7th Heat Transfer Conf., Munich.
Batchelor, G. K. 1954 Heat convection and buoyancy effects on fluids. Q. J. R. Met. Soc. 80, 339–358.Google Scholar
Beuther, P. D. 1980 An experimental investigation of the turbulent buoyant plume. PhD Dissertation, SUNY at Buffalo, Buffalo, NY.
Beuther, P. D. & George, W. K. 1982 The turbulent buoyant plume in a stratified environment. Proc. Natl Congr. Theor. and Appl. Mech., Cornell University, Ithaca, NY.
Chen, C. J. & Rodi, W. 1980 Vertical Turbulent Buoyant Jets. Pergamon.
George, W. K. 1990 Governing equations, experiments, and the experimentalist. Exp. Thermal Fluid Sci. 3, 557–566.Google Scholar
George, W. K. Jr., Alpert, R. L. & Tamanini, F. 1977 Turbulence measurements in an axisymmetric buoyant plume. Intl J. Heat Mass Transfer 20, 1145–1154.Google Scholar
George, W. K., Beuther, P. D. & Shabbir, A. 1989 Polynomial calibrations for hot wires in thermally-varying flows. Exp. Thermal Fluid Sci. 2, 230–235.Google Scholar
Hussein, H. J., Capp, S. P. & George, W. K. 1994 Velocity measurements in a high Reynolds number momentum-conserving axisymmetric turbulent jet. J. Fluid Mech. 258, 31–75.Google Scholar
Kotsovinos, N. E. 1985 Temperature measurements in a turbulent round plume. Intl J. Heat Mass Transfer 28, 771–777.Google Scholar
Kotsovinos, N. E. & List, E. J. 1977 Turbulent buoyant jets. Part 1. Integral properties. J. Fluid Mech. 81, 25–44.Google Scholar
List, E. J. 1982 Turbulent jets and plumes. Ann. Rev. Fluid Mech. 114, 189–212.Google Scholar
List, E. J. & Imberger, J. 1973 Turbulent entrainment in buoyant jets and plumes. Proc. ASCE, J. Hydraul. Div. 99, 1416–1474.Google Scholar
Lumley, J. L. 1971 Explanation of thermal plume growth rates. Phys. Fluids 14, 2537–2538.Google Scholar
Lumley, J. L. 1978 Computational modeling of turbulent flows. Adv. Appl. Mech. 18, 123–176.Google Scholar
Morton, B. R. 1959 Forced plumes. J. Fluid Mech. 2, 151–163.Google Scholar
Morton, B. R., Taylor, G. I. & Turner, J. S. 1956 Turbulent gravitational correction from maintained and instantaneous sources. Proc. R. Soc. Lond. A 234, 1–23.Google Scholar
Nakagome, H. & Hirata, M. 1977 The structure of turbulent diffusion in an axisymmetrical thermal plume. In Proc. 1976 ICHMT Seminar on Turbulent Buoyant Convection, pp. 361–372. Hemisphere.
Ogino, F., Takeuchi, H., Kudo, I. & Mizushina, T. 1980 Heated jets discharged vertically into ambients of uniform and linear temperatures profiles. Intl J. Heat Mass Transfer 23, 1581–1588.Google Scholar
Papanicolaou, P. N. & List, E. J. 1987 Statistical and spectral properties of tracer concentration in round buoyant jets. Intl J. Heat Mass Transfer 30, 2059–2071.Google Scholar
Papanicolaou, P. N. & List, E. J. 1988 Investigations of round vertical turbulent buoyant jets. J. Fluid Mech. 195, 341–391.Google Scholar
Papantoniou, D. & List, E. J. 1989 Large scale structure in the far field buoyant jets. J. Fluid Mech. 209, 151–190.Google Scholar
Rodi, W. 1986 Vertical turbulent buoyant jets: experimental findings and prediction methods. Proc. Intl Symp. on Buoyant Flows, Athens, Greece, Sept. 1–5.
Rouse, J., Yih, C. S. & Humphrey, H. W. 1952 Gravitational convection from a boundary source. Tellus 4, 201.Google Scholar
Schmidt, W. 1941 Turbulent propagation of a stream of air. Z. Angew. Math. Mech. 21, 265–278.Google Scholar
Shabbir, A. 1987 An experimental study of axisymmetric turbulent buoyant plume and investigation of closure hypotheses. PhD dissertation, SUNY at Buffalo, Buffalo, NY.
Shabbir, A. Beuther, P. B. & George, W. K. 1994 X-wire response in turbulent flows of high intensity turbulence and low mean velocities. Exp. Thermal Fluid Sci. (submitted).Google Scholar
Shabbir, A. & George, W. K. 1985 Measurements of temperature and velocity in an axisymmetric turbulent buoyant plume. Bull. Am. Phys. Soc. 30, 10, Abstract DD6.Google Scholar
Shabbir, A. & George, W. K. 1987 An experimental study of an axisymmetric turbulent buoyant plume in a neutral environment. Proc. 6th Turbulent Shear Flow Conf., Toulouse, pp. 9-3-1–9-3-6.
Shabbir, A. & George, W. K. 1992 Experiments on a round turbulent buoyant plume. NASA TM 105955.
Tennekes, H. & Lumley, J. L. 1972 A First Course in Turbulence. MIT Press.
Townsend, A. A. 1956 Structure of Turbulent Shear Flows. Cambridge University Press.
Tutu, N. K. & Chevray, R. 1975 Cross-wire anemometry in high intensity turbulence. J. Fluid Mech. 71, 785–800.Google Scholar
Zel'dovich, Ya, B. 1937 Limiting laws for turbulent flows in free convection. Zh. Eksp. Theoret. Fiz 7, 1463.Google Scholar
Supplementary material: PDF

Shabbir and George supplementary material

Table 4-8

Download Shabbir and George supplementary material(PDF)
PDF 821.3 KB