Average rise velocity
 

Hi,

I am studying behavior of a large air bubble rising in water. How I can get rise velocity from Function Calculator?

I have two ideas:

1.- Create a isovolume at air volume fraction between 0 and 1, and use function VolumeAve with air velocity as variable.

2.- Create a isosurface at air volume fraction = 0.5, and use function AreaAve with air velocity as variable.

I get different results from two ways. What is the right option? Do you have some new idea?

Thanks in advance Miguel