Mixing in a fluid jet agitated tank: Geometric effects

Experimental and numerical investigations of mixing in fluid jet agitated tanks were carried out. Experiments were performed in a 23 litre tank. Numerical models to describe mixing in such a tank were developed using computational fluid dynamics (CFD), and the results validated against experimental data. The effects of alternative shapes of the tank bottom were investigated. An improvement in mixing time was observed when a hemispherical base was used instead of a flat base. The mixing time reduced by about 25% for a jet Reynolds number of 9000, and by about 15% for a jet Reynolds number of 40,000. Further reduction in mixing time was also observed when a conical base was used instead of a flat base. The 99% mixing time (t₉₉) was also calculated and compared with the predicted 95% mixing time (t₉₅), and with other predictions using published correlations.