Experimental and computational studies of turbulent mass transfer in a mixing channel

Experiments are carried out for passive mixing in order to obtain local mean and turbulent velocities and concentrations. The mixing takes place in a square channel with two inlets separated by a block. A combined PIV/PLIF technique is used to obtain instantaneous velocity and concentration fields. Three different flow cases are studied. The 2D numerical predictions of the mixing channel show that none of the k - ε turbulence models tested is suitable for the flow cases studied here. The turbulent Schmidt number is reduced to obtain a better agreement between the measured and predicted mean and fluctuating concentrations. The multi-peak presumed PDF mixing model is tested and comparisons with experiments are encouraging