gas velocity specification
 

i am using cfx4.3.my query is regarding ref.example titled "bubbly flow in a draft tube"(CFX examples given alongwith the software).a sparger is provided in the example with a source TERM for velocity,pressure.is there a way for directly specifying inlet gas velocity,volume fraction for this problem? the next ref example is "MUSIG model in a pipe".here i would like to modify the problem by considering the case of a batch of liquid uniformly aerated by gas at the bottom.is there a way?