Journal of Fluid Mechanics

Organized structures in a turbulent plane jet: topology and contribution to momentum and heat transport

R. A.  Antonia a1, A. J.  Chambers a1, D.  Britz a1 and L. W. B.  Browne a1
a1 Department of Mechanical Engineering, University of Newcastle, N.S.W., 2308, Australia

Article author query
antonia ra   [Google Scholar] 
chambers aj   [Google Scholar] 
britz d   [Google Scholar] 
browne lw   [Google Scholar] 


In the self-preserving region of a slightly heated turbulent plane jet, conventional isocorrelation contours of velocity and temperature fluctuations support the existence of organized large-scale structures. Temperature fronts associated with these structures were visually detected using a spanwise rake of cold wires. This method of detection was then used to condition velocity and temperature fluctuations and products of these fluctuations. Ensemble-averaged velocity vectors, constructed in the plane of main shear, suggest a topology for the organized motion in which the temperature front is identified with the diverging separatrix connecting adjacent structures on the same side of the centreline. Coherent stresses and heat fluxes are particularly significant near the diverging separatrix. Contributions by the coherent and random motions to the averaged momentum and heat transports are generally of the same order of magnitude.

(Published Online April 21 2006)
(Received September 27 1984)
(Revised April 2 1986)