THERMAL SCIENCE

International Scientific Journal

Houda Mahmoud

,

Wassim Kriaa

,

Hatem Mhiri

,

Georges Le Palec

,

Philippe Bournot

STUDY OF THE PARABOLIC AND ELLIPTIC APPROACHES VALIDITIES FOR A TURBULENT CO-FLOWING JET

ABSTRACT
An axisymmetric turbulent jet discharged in a co-flowing stream was studied with the aid of parabolic and elliptic approaches. The simulations were performed with two in-house codes. Detailed comparisons of data show good agreement with the corresponding experiments; and different behaviors of jet dilution were found in initial region at different ranges of velocities ratios. It has been found that the two approaches give practically the same results for the velocities ratios Ru ≤ 1.5. Further from this value, the elliptic approach highlights the appearance of the fall velocity zone and that’s due to the presence of a trough low pressure. This fall velocity has not been detected by the parabolic approach and that’s due to the jet entrainment by the ambient flow. The intensity of this entrainment is directly related to the difference between the primary (jet) and the secondary flow (co-flow). In fact, by increasing the velocities ratios Ru, the sucked flux by the outer stream becomes more important; the fall velocity intensifies and changes into a recirculation zone for Ru ≥ 5.
KEYWORDS
axisymmetric jet, turbulence, co-flow, recirculation zone, parabolic approach, elliptic approach
PAPER SUBMITTED: 2010-11-04
PAPER REVISED: 2011-06-27
PAPER ACCEPTED: 2011-10-06
DOI REFERENCE: https://doi.org/10.2298/TSCI101104097M
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2012, VOLUME 16, ISSUE Issue 1, PAGES [223 - 238]
REFERENCES
  1. Benarous, A., Liazid, A., H2-O2 supercritical combustion modeling using a CFD code, Thermal Science, 13 (2009), 3, pp. 139-152.
  2. Antonia, R. A., Bilger, R. W., An experimental investigation of an axisymmetric jet in a coflowing air stream, Journal of fluid Mechanics, 61(1973), pp.805-822.
  3. Nickels, T. B., Perry, A. E., An experimental and Theoretical study of the turbulent coflowing jet, Journal Fluid Mechanics, 309(1995), pp. 157-182.
  4. Mesnier, B., Studies on the development of turbulent jets with variable density in axisymmetric and asymmetric geometries (In Frensh), Ph. D. Thesis, Orleans University, 2001.
  5. Antoine, Y., Fabrice, L., Michel, L., Turbulent transport of a passive scalar in a round jet discharging into a co-flowing stream, Journal Mechanics B. Fluids, 20(2001), pp. 275-301.
  6. Imine, B., et al., Study of non-reactive isothermal turbulent asymmetric jet with variable density, Comput. Mechanics, 38(2006), pp. 151-162.
  7. Habli, S., et al., Influence of a Coflowing Ambient Stream on a Turbulent Axisymmetric Buoyant Jet, Journal Heat Transfer, 130 (2008), 2, pp. 1-15.
  8. Wei-Biao, F., et al. The use of co-flowing jets with large velocity differences for the stabilization of low grade coal flames, Twenty first Symposium (International) on Combustion/the combustion Institute, 1986, pp. 567-574.
  9. Mahmoud, H., et al., A numerical study of a turbulent axisymmetric jet emerging in a co-flowing stream, Energy Conversion and Management, ELSEVIER, 51(2010), pp. 2117-2126.
  10. Martynenko, O. G., Korovkin, V. N., Flow and heat transfer in round vertical buoyant jets, International Journal Heat Mass Trans, 37(1994),1, pp.51-58.
  11. Hossain, M. S., Rodi, W., A turbulent model for boyant flows and its application to vertical boyant jets. Pergamon, New York, 1982, pp. 121-178.
  12. Habli, S., Mhiri, H., Golli, S., Etude numérique des conditions d'émission sur un écoulement de type jet axisymétrique turbulent, International Journal Thermal Science, 40(2001), pp. 497-511.
  13. Fluent Incorporated 6.2.16.
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Study of the parabolic and elliptic approaches validities for a turbulent co-flowing jet

© 2024 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence