Journal of Fluid Mechanics

On turbulence and noise of an axisymmetric shear flow

A.  Michalke a1 and H. V.  Fuchs a2
a1 Institut für Thermo- und Fluiddynamik, Technische Universität, Berlin
a2 DFVLR-Institut für Turbulenzforschung, Berlin

Article author query
michalke a   [Google Scholar] 
fuchs hv   [Google Scholar] 


The noise produced by mean flow-turbulence interaction of a circular subsonic jet is investigated theoretically, and expanded in azimuthal constituents of the turbulent pressure fluctuations. It is found that the low-order azimuthal constituents are the most efficient sound sources. On the basis of pressure correlation measurements, the azimuthal constituents are determined in a low Mach number jet. It is found that, in a range of Strouhal numbers between 0·2 and 1, the first three to four azimuthal constituents clearly dominate over the rest of the turbulent source quantity. A strictly axisymmetric ring vortex model for the coherent structure of the turbulence is, however, shown to be inappropriate.

(Published Online March 29 2006)
(Received July 15 1974)
(Revised November 18 1974)