Menu

Discussion Forum

New Discussion
Filtrer

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.

Rising bubble problem

Posted 22 janv. 2021, 10:54 UTC−5 Fluid & Heat, Computational Fluid Dynamics (CFD) 5 Replies

Niraj Sonule
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

I am trying to simulate bubble rise problem. I want to find its center of mass and rising velocity at different time step. Please help me with this. It will be very greatfull.

Thank you.

5 Replies Last Post 25 janv. 2021, 08:58 UTC−5
Jeff Hiller COMSOL Employee

Please login with a confirmed email address before reporting spam

Posted: 4 years ago 22 janv. 2021, 11:29 UTC−5
Updated: 4 years ago 24 janv. 2021, 12:24 UTC−5

Hello Niraj,

This model shows how to model a rising bubble.

Best,

Jeff

-------------------
Jeff Hiller
Hello Niraj, [This model](https://www.comsol.com/model/rising-bubble-177) shows how to model a rising bubble. Best, Jeff
Niraj Sonule
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 4 years ago 24 janv. 2021, 09:02 UTC−5

Hello Mr. Jeff, Thank you for your reply but i couldn't find any model in your reply. I am a learner. Thanks for your support.

Hello Mr. Jeff, Thank you for your reply but i couldn't find any model in your reply. I am a learner. Thanks for your support.
Jeff Hiller COMSOL Employee

Please login with a confirmed email address before reporting spam

Posted: 4 years ago 24 janv. 2021, 12:24 UTC−5

I fixed the link.

Jeff

-------------------
Jeff Hiller
I fixed the link. Jeff
Niraj Sonule
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 4 years ago 24 janv. 2021, 22:53 UTC−5

I had read the procedure in that tutorial but there is no mention of determing the center of mass and rising velocity of bubble with respect to time, which are one of the major criterion for simulating this physics. It will be greatfull if you can tell me how to do this.

Thanking you.

Niraj

I had read the procedure in that tutorial but there is no mention of determing the center of mass and rising velocity of bubble with respect to time, which are one of the major criterion for simulating this physics. It will be greatfull if you can tell me how to do this. Thanking you. Niraj
Jeff Hiller COMSOL Employee

Please login with a confirmed email address before reporting spam

Posted: 4 years ago 25 janv. 2021, 08:58 UTC−5
Updated: 4 years ago 25 janv. 2021, 09:29 UTC−5

Hi Niraj,

Sorry. From your initial message I had not understood that you had the model done. With your model already in place, computing the location of the center of mass will, I expect, be a relatively simpler, postprocessing, task. If it was me, I would tackle it by using nonlocal couplings of the integration type to compute the average x- and the average y-coordinate in the bubble (I'd use a boolean expression based on the value of the level set function to detect whether a point lies inside or outside of the bubble). Once you have the coordinates of this center of mass of the bubble, you can get to its x- and y-velocities by differentiation w.r.t. time.

Best,

Jeff

-------------------
Jeff Hiller
Hi Niraj, Sorry. From your initial message I had not understood that you had the model done. With your model already in place, computing the location of the center of mass will, I expect, be a relatively simpler, postprocessing, task. If it was me, I would tackle it by using nonlocal couplings of the integration type to compute the average x- and the average y-coordinate in the bubble (I'd use a boolean expression based on the value of the level set function to detect whether a point lies inside or outside of the bubble). Once you have the coordinates of this center of mass of the bubble, you can get to its x- and y-velocities by differentiation w.r.t. time. Best, Jeff

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