Main Article Content



Experimental investigation of the free turbulent swirl jet behind the axial fan, by use of the three-component laser Doppler anemometer (LDA) is presented in this paper. Axial fan generates Rankine swirl. Measurements have been performed in five vertical measuring sections downstream for one rotation number 1500 rpm. Time averaged velocity components and their profile transformation downstream were investigated. Statistical moments of the second, third and fourth order have been calculated and presented. The highest turbulence levels are reached in the central zone, more precisely shear layer zone and in the injection zone. Skewness and flatness factors differ from normal Gaussian distributions. Turbulence swirl flow anistropy is investigated by applying invariant maps. Most of the obtained results are positioned in the region of the three-component isotropic turbulence and axisymmetric expansion.

Article Details

How to Cite
JANKOVIĆ, Novica Z.. INVESTIGATION OF THE FREE TURBULENT SWIRL JET BEHIND THE AXIAL FAN. Thermal Science, [S.l.], mar. 2017. ISSN 2334-7163. Available at: <>. Date accessed: 24 feb. 2018. doi:
Received 2017-03-08
Accepted 2017-03-14
Published 2017-03-14


[1] Dey, International standard ISO 5801:2007: Industrial fans - Performance testing using standardized airways.
[2] Pratte, B.D., Keffer, J.F., The Swirling Turbulent Jet, J. of Basic Eng., 94 (4) (1972), pp. 739-747
[3] Čantrak Đ.S., et al. (2012): Turbulent Swirl Flow Characteristics and Vortex Core Dynamics behind Axial Fan in a Circular Pipe, Proceedings, Conference on Modelling Fluid Flow (CMFF’12), The 15th International Conference on Fluid Flow Technologies, Budapest, Hungary, September 4-7, Ed. J. Vad, Vol. II, pp. 749-756, ISBN 978-963-08-4587-8, CD-ROM ISBN 978-963-08-4588-5.
[4] Čantrak, Đ.S., Analysis of the vortex core and turbulence structure behind axial fans in a straight pipe using PIV, LDA and HWA methods, Ph.D. thesis, Univ. of Belgrade, Faculty of Mech. Eng., Belgrade, 2012.
[5] Čantrak, S.M., Experimental investigation of statistical properties of turbulent swirl flow in pipe and diffusers, Ph.D. thesis, Karlsruhe University (TH), Institute of Fluid Machinery, Karlsruhe, 1981
[6] Benišek, M.H. et al., Investigation of the Turbulent Swirl Flows in a Conical Diffuser, Thermal Science, Vol. 14 (2010), Supplement 1, pp. S141 - S154
[7] Čantrak Đ.S., et al., Investigation of the Turbulent Swirl Flow in Pipe Generated by Axial Fans using PIV and LDA Methods, Theoretical and Applied Mechanics, Vol. 42 (2015), Issue 3, pp. 211-222
[8] Čantrak, Đ. S., et al.,. Laser Insight into the Turbulent Swirl Flow behind the Axial Flow Fan, Proceedings, ASME Turbo Expo 2014: Turbine Technical Conference and Exposition, GT 2014, Tech- nical track: Fans and Blowers, ASME TURBO EXPO 2014, Düsseldorf, Germany, 2014, Paper No. GT2014-26563, pp. V01AT10A024, 10 pages
[9] Lumley, J.L. and Newman, G., 1977. "The return to isotropy of homogeneous turbulence", Journal of Fluid Mechanics., 82, pp. 161-168.
[10] Elsner J.W., Drobniak S., Turbulence Structure in Swirling Jets, in: Structure of Complex Turbulent Shear Flow, IUTAM Symposium, Springer, Marseille, 1982, pp. 219-228
[11] Ilić, D.B., Swirl Flow in Conical Diffusers, Ph.D. thesis, Univ. Belgrade, Faculty of Mech. Eng., Bel- grade, Serbia, 2013
[12] Sander, G. F.; Lilley, D. G. The Performance of an Annular Vane Swirler. AIM Paper No. 83-1326, Seattle , Washington, June 27-29, (1983).
[13] Javadi, A., Nilsson., H., LES and DES of strongly swirling turbulent flow through a suddenly expanding circular pipe, Computers & Fluids, Vol. 107 (2014), pp. 301-313Corke, T. C., et al., Single Dielectric Barrier Discharge Plasma Enhanced Aerodynamics, Experiments in Fluids, 46 (2009), 1, pp. 1-26
[14] Šekularac, M., Analysis of flow fields in complex ventilation systems of traffic tunnels. PhD thesis, Univ. of Montenegro, Faculty of Mech. Eng., Montenegro, 2015.
[15] Gilchrist R. T., Naughton J. W., Experimental Study of Incompressible Jets with Different Initial Swirl Distributions: Mean Results, AIAA journal, Vol. 43, No. 4, April 2005
[16] Mehta R. D., et al. Some effects of swirl on turbulent mixing layer development, Physics of Fluids, Vol.3, (1991), Issue 11, pp. 2716-2724
[17] Sislian J. P., Cusworth R. A., Measurements of Mean Velocity and Turbulent Intensities in a Free Iso- thermal Swirling Jet, AIAA Journal, Vol. 24 (1986), No.2, pp. 303-309.