Numerical analysis
The alignment of mixing of different type/scale of mixers was based on equivalent power input per unit volume (P/V ). This value were either predicted from CFD simulation or directly calculated from the impeller power number (Np ) provided by the vendor. The moment (M) of impeller surfaces (N m) obtained from the converged first-step model was used to calculate the simulatedP/V value by Eq. 1.
\(P/V=2\pi\bullet N\bullet M/V\) (1)
Where, N is the agitation rate (s-1); Vis the liquid volume (m3).
The Np derived P/V value was calculated by Eq. 2.
\(P/V=N_{P}\rho N^{3}D^{5}/V\) (2)
Where, D is the impeller diameter (m); and ρ is the liquid density (kg m-3).