Mixing (or blending) time is the time taken to homogenize the liquid contents of a tank after a step change in composition. The transport of a tracer helps to understand the degree of homogeneity in the agitated tank. Mixing time is historically difficult to predict accurately because of the wide range of variables involved. This makes scale-up and scale-down more complex. Using CFD eliminates the guesswork in tank configuration, scale, and fluid properties. CFD modeling lets you leverage the flexibility of changing tank scale, flow regimes/impeller location and number of impellers until the best configuration is obtained.

Concentration of the tracer can be monitored at a number of locations in the vessel and plotted as uniformity of concentration, U, as a function of time.