Taylor bubble Shape in Vertical tube
 

Dear all, I am totally new and I want to simulate the Taylor Bubble rising in vertical tube using VOF method. When I set up the initial condition, I will use field function and bubble length is 90mm and bubble radius is 12mm and I just wanna know if the field function for bubble is right or not. If I was wrong, Let me know what is wrong. Thanks


What I set up is ($$position[0]>=0&&$$position[0]<=0.012&&$$position[1]>=0.078&&$$position[1]<=0.09&&sqrt(pow($$position[0],2)+pow($$position[1],2))<=0.012)?1:
(($$position[0]>=0&&$$position[0]<=0.012&&$$position[1]>=0&&$$position[1]<0.078))?1:0