Numerical Study of the Scaling Rules for Riser with Consideration of Cluster Effect.

The validation of scaling rules with the consideration of cluster effect is investigated by two-fluid models. Glicksman's full and simplified scaling rules are used to build two 1:3 scaled-up risers. The cluster features within different particle classes or operation conditions are approached with the energy minimization multiscale drag model. The comparison of axial and radial solids concentration between three cases indicates that the simplified set scaled riser produces a poor fit throughout the length of the riser and that the full set scaled riser produces a good similarity only toward the top half of the riser. The analysis of cluster characteristics of three cases illustrates that the accurate repetition of the clusters is essential for the hydrodynamic similarity. The simplified set scaled riser presents lower cluster characteristic values along the riser, and the full set presents poor similarity of cluster characteristics in the riser's bottom region. [ABSTRACT FROM AUTHOR]