Experimental analysis of the turbulent field of a coaxial jet configuration

The mean axial velocity field and the moments of the axial and radial fluctuations of a coaxial jet configuration are described by means of LDA and hot-wire measurements. The data may be useful both for a characterization of the mixing process between two jets, and as reference for the validation of CFD codes, and in particular of their turbulence models. The spectral analyses of both velocity components allows the presence of alternate vortex shedding from the wake of the inner duct wall to be recognized and characterized. The existence of dominating frequencies in the coherent vortical structures at the end of the potential cores is also singled out from both the spectra and conditioned averages of the velocity fluctuations.