UFD problem in DPM.
 

hi,all

my model is to calculate a gas-liquid flow in a water tank, different forces should be imposed on the bubbles, when the bubbles were under a horizontal wall, press and buoyant force are to be added; and if not, only buoyant force are to be added.

would you please tell me how to use UDF to add different forces on the same bubble at different section of the water system in a model(i.e. the forces on bubbles are different when they changes the positions) ?

thanks!