International Scientific Journal


The aim of this study is to examine different blowing configurations of multiple swirling jets for use it in terminal units of ventilation applications. The influence of several parameters such as the inclined vanes of diffuser and the sense of rotation of the single or multiple swirling jets, their number and their arrangement on the flow resulting dynamically and thermally is experimentally investigated. Flow rate was adjusted at Reynolds numbers, Re0, ranging from 104 to 30.103. The current study is carried out under uniform heat flux condition for each diffuser at Reynolds number of 30.103, the air being the working fluid. Experiences concerning the fusion of several jets show that the resulting jet is clearly more homogenized under swirling influence. The findings of this study show that the gap between the jets and their sense of rotation relative to the central jet, affects the quality of the homogenization of ambiance. Among the studied different configuration, the one which consists of a swirling central jet controlling the behavior of six swirling jets in counter-rotation is shown to be the most effective in terms of thermal destratification.
PAPER REVISED: 2011-11-04
PAPER ACCEPTED: 2011-11-30
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THERMAL SCIENCE YEAR 2012, VOLUME 16, ISSUE Issue 1, PAGES [239 - 250]
  1. Lalot, S., Poitier, X., Loukarfi, L., Using swirling mixing jets for homogeneous blowing, Transactions of the Canadian Society for Mechanical Engineering, 25 (2001), 1, pp. 51-62
  2. Heitor, M.V., Moreira, A.L.N., On the analysis of turbulent transport processes in non reacting multijet burners flows, Experiments in Fluids, 13 (1992), pp. 179-189
  3. Isaac Manohar, C. H., Sundararajan, T., Ramjee, V., Sasi Kumar, S., A numerical and experimental investigation of the interactions between a non-uniform planar array of incompressible free jets, International Journal of Numerical Methods in Fluids, 44 (2004), 4, pp. 431-446
  4. Al-Shyyab, S., Tlilan, H., Ababneh, A., Enhancement of a cylindrical separator efficiency by using double vortex generators, Energy Conversion Management, 50 (2009), pp. 1625-1633
  5. Volchkov, E.P., An experimental study of the flow stabilization in a channel with a swirled periphery jet, Intentional Journal of Heat and Mass Transfer, 43 (2000), pp. 375-386
  6. Jebamani, D. R., Kumar, T. M. N., Studies on variable swirl intake system for di diesel engine using computational fluid dynamics, Thermal Science, 12 (2008), 1, pp. 25-32
  7. Huang, Y., Yang, V., Dynamics and stability of lean-premixed swirl-stabilized combustion, Progress in Energy and Combustion Science, 35 (2009), pp. 293-364
  8. Ahmadvand, M., Najafi, A. F., Shahidinejad, S., An experimental study and CFD analysis towards heat transfer and fluid flow characteristic of decaying swirl pipe flow generated by axial vanes, Meccanica, 45 (2010), pp. 111-129
  9. Benišek, M. H., Ilić, D. B., Čantrak, Đ. S., Božić, I. O., Investigation of the turbulent swirl flows in a conical diffuser, Thermal Science, 14 (2010), suppl., pp. 141-154
  10. Lee, S., Park, S. H., Yeo, M. S., Kim, K. W, An experimental study on airflow in the cavity of a ventilated roof, Building and Environment, 44 (2009), pp. 1431-1439
  11. Zhao-Qin, Y., Experimental study on the flow field characteristic in the mixing region of twin jets, Journal of Hydrodynamics, 19 (2007), 3, pp. 309-313
  12. Oyakawa, K., Hanashiro, K., Matsuda, S., Yaga, M., Hiwada, M., Study on Flow and Heat Transfer of Multiple Impingement Jets", Heat Transfer-Asian Research, 34 (2005), 6, pp. 419-431
  13. Lee, D. H, Won, S. Y., Kim, Y. T., Chung, Y. S., Turbulent heat transfer from a flat surface to a swirling round impinging jet, International Journal Heat and Mass Transfer, 45 (2002), 1, pp. 223-227
  14. Valentina, C., Easson, W. J., Optimisation of furnace design for in-furnace NOx reduction: the effect of pitch spacing on multiple burner jet interactions, Fuel, 82 (2003), pp. 2075-2085
  15. Yimer, I., Becker, H. A., Grandmaison, E. W., Development of flow from multiple-jet burners, The Canadian Journal of Chemical Engineering, 74 (1996), pp. 840-851
  16. Giorges Akililu, T. G., Forney, L. J., Xiaodong, W., Numerical study of multi-jet mixing: Fluid flow, Chemical Engineering Research & Design, 79 (2001), 5, pp. 515-522
  17. Nakod, P. M., Prabhu, S. V., Vedula, R. P., heat transfer augmentation between impinging circular air jet and flat plate using finned surfaces and vortex generators, Experimental Thermal and Fluid Science, 32 (2008), pp.1168-1187
  18. Felli, M., Falchi M., Pereira, F. G. A., Distance effect on the behaviour of an impinging swirling jet by PIV and flow visualizations, Experiments in Fluids, 48 (2010), pp. 197-209
  19. Protić, Z. D., Nedeljković, M. S., Čantrak D. S., Janković, N. Z., Novel methods for axial fan impeller geometry analysis and experimental investigations of the generated swirl turbulent flow, Thermal Science, 14 (2010), pp. 125-139
  20. Gupta, A.K., Lilley, D.G., Syred, N., Swirl flows, London: Abacus Press, 1984
  21. Huang, Y., Yang, V., Dynamics and stability of lean-premixed swirl-stabilized combustion, Progress in Energy and Combustion Science, 35 (2009), 4, pp. 293-364
  22. Sislian, J. P.,Cursworth, R.A., Measurements of mean velocity and turbulent intensities in a free isothermal swirling jet, AIAA Journal, 24 (1986), 2, pp. 303-309
  23. Volchkov, E. P., Matovich, M., Oka, S., Spotar, S. YU., Chokhar, I. A. Use of a laser Doppler anemometer to study turbulent swirled jets, Heat Transfer, Soviet Research, 23, (1991), 4, pp. 470-502
  24. Florent, P., Loukarfi, L., Using a mixture of helical jets for heating large buildings, French Congress of Thermal, French Society of Thermal (SFT), Valenciennes, France, (1996), pp. 13-15

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