Turbulent mixing in a coflowing liquid jet

Mixing in an axisymmetric concentrated KCl solution jet emerging in a less salty coflowing water has been experimentally investigated. This has been a chieved by coupling laser Doppler velocimetry to a microconductimetry techn ique in view of measuring the turbulent fluxes (cu) over bar and (cv) over bar and deducing the turbulent diffusivity. The cross-correlation coefficie nt between radial velocity and concentration R-cv reaches a maximum value o f 0.77 when the one relative to axial velocity R-cu gets smaller and does n ot exceed 0.37 under the same conditions. The total turbulence intensity, g lobal microscale, kinetic energy dissipation rate, and turbulent diffusion coefficient in the radial direction have also been determined. In a jet sec tion, the turbulent diffusion coefficient was found to vary from 180 to 200 0 times the KCl molecular diffusivity D-m.