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abdoganawa March 17, 2013 11:35

problem in slug flow simulation
Hello all,
Actually Iam facing a problem in a simulation of slug flow, I used VOF model for straight pipe with one inlet, initial volume fraction distribution was defined that the half of the pipe occupied with water and the other half with air, my problem is the pipe inlet became fully occupied with water only after several time steps.... I suspected that due to improper defining for the velocity at the inlet previously I used this field function
[($$Position[1] < 0),0,0? 2: 1.2] which it supposed to express velocity in i direction is 2 if y<0 (this represent water phase) else the velocity is 1.2
then I change this function to
[($$Position[1] < 0),0,0? $Velocity_water_inlet : $Velocity_air_inlet]
$Velocity_water_inlet =2
but still the result is same no difference from the previous trial.
is the both of those field function didn't define the velocity inlet for air phase, so the pipe became fully of water only?

any suggestion.....
to make the picture clear I used this for initial water volume fraction distribution ($$Position[1] < 0)? 1:0 and the initial vf was well initiated


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