Vortex Identification Methodology for Feed Insertion Guidance in Fluid Mixing Processes

A vortex tracking methodology is developed to determine the precessional frequency and the characteristics of macroinstability (MI) vortices. The methodology is compared with other techniques, frequency analysis and correlation coeffcient, which are most commonly used to assess periodicities in a flow. Two sets of experiments were carried out, 2D PIV and two-point LDA, in two different scaled vessels of diameter 80 mm and 294 mm. The MI characteristics were studied for two different Re (i.e., 32 000 and 3200) by correlating the vortex intensity (vorticity and pressure suction) with its radius at different axial positions. This study provides relevant data for the optimisation of mixing time as it indicates ‘preferred’ positions, on the path of the MI vortex, where the insertion of a second phase should take place in order to fully exploit the suction potential of the MI vortex.