Menu

Discussion Forum

New Discussion
Filtern

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Finding volume of bubbles

Posted 31.07.2021, 00:06 GMT-4 Computational Fluid Dynamics (CFD), Heat Transfer, Microfluidics 1 Reply

Niraj Sonule
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Hello everyone, I am simulating a problem which has two bubbles aligned vertically seperated by some distance. They both rise vertically up due to buoyancy. The domain is axi-symmetric and level-set method is used for solving the two-phase problem.

I want to calculate volume of the two bubbles (per radian) seperately.

Please help me doing so. Thank you in advance.

Niraj

1 Reply Last Post 01.08.2021, 05:34 GMT-4
Alexis Prel
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 3 years ago 01.08.2021, 05:34 GMT-4
Updated: 3 years ago 01.08.2021, 12:18 GMT-4

Hello Niraj,

In the model builder, for each bubble :

  • define a named selection
  • define a domain integration operator and sets its domain of application to the named selection you just created. Default names will be intop1 and intop2 but you may change it to something more explicit
  • create a variable volume_1 = intop1(2*pi*r)

Hence, you are integrating the function 2*pi*r where r denotes the radial coordinate of your axi-symmetric problem. Without the axial symmetry, you should integrate the constant function 1 instead. I would not be surprised to learn that COMSOL already takes care of the 2*pi*r factor for you, so you should check with a simple geometry (such as a cylinder) which of these two integrands gives the correct result.

Hello Niraj, In the model builder, for each bubble : * define a named selection * define a domain integration operator and sets its domain of application to the named selection you just created. Default names will be `intop1` and `intop2` but you may change it to something more explicit * create a variable `volume_1 = intop1(2*pi*r)` Hence, you are integrating the function `2*pi*r` where `r` denotes the radial coordinate of your axi-symmetric problem. Without the axial symmetry, you should integrate the constant function `1` instead. I would not be surprised to learn that COMSOL already takes care of the `2*pi*r` factor for you, so you should check with a simple geometry (such as a cylinder) which of these two integrands gives the correct result.

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.

Suggested Content