How to enable drift velocity correction in eulerian multiphase model in FLUENT-6.1?
There is no information available in USER's GUIDE on how to enable the drift velocity correction in the problem set up while dealing with an Eulerian Multiphase simulation. The User's Guide Section:- 22.4.8 "Turbulence Models". says:
"The drift velocity results from turbulent fluctuations in the volume fraction. When multiplied by the exchange coefficient , it serves as a correction to the momentum exchange term for turbulent flows. This correction is not included, by default, but you can enable it during the problem setup".
How can one enable the correction?
One can enable the effect of drift velocity through the following TUI commands.
k-epsilon multiphase model: 
The above TUI command (where option 1 is selected for k-epsilon multiphase model), selects the turbulence model as "dispersed". This can also be done through GUI panel as well.
In the similar way:- 0 means Mixture
2 means per phase
Enable interphase momentum source? [no]
Enable interphase k-epsilon source? [yes]
The second option in the above menu, enables the effect of drift velocity, when one answers yes to the second question.