The first is that there is an error in the program itself. The expression of v_m is incorrect. V0_m is density multiplied by volume, and bv is volume fraction multiplied by volume.

In ID /*42*/, V is undefined!

Then one, my last suggestion you didn't understand. According to the present statement, it should be a mixture of bubble movement and movement!

My last suggestion is to track the interface changes and the deformation or movement of bubbles during the movement.

You can add me QQ specifically. Since I have never done this work before, I want to expand my application skills and exchange opinions.1