seperation of drag forces
 

hi,
i have run a multiphase VOF simulation of a body part submerged in water and part in air, is there a way in which i can seperate from the drag results how much is from air and how much is from water? I am currently using the density of the water as my reference value also,

thanks in advance

Separation
 

If you want to determine drag at a particular instant of time, then you can mark the cells with volume fraction of either liquid or gas and then use this register to separate the face into two; one will automatically be adjacent to liquid and the other to gas. Then you can report separate forces and coefficients. However, if this is to be done continuously in a transient case, then you cannot separate the face because the interface won't be fixed. The only way would be to use UDF then. Or you can use a custom field function to determine shear stress and pressure and then use those to calculate forces.