I am modelling a laminar flow problem in a microchannel in a transient mode. My model works well but when I change the inlet boundary condition to velocity instead of pressure it does not converge. The outlet is pressure boundary condition.
I get the below message:
Nonlinear solver did not converge.
Maximum number of Newton iterations reached.
Time : 0
Last time step is not converged.
Also when I change the viscosity to non newtonian, my model only works with velocity
inlet boundary condition and not the pressure?
Hi there,
I would have to take a look at your script but in principle it should work. Sometimes COMSOL has a bug and redoing the model from scratch solves the problem.
Nevertheless, my suggestion would be for you to take a look at a model (attached) and just adapt it to your needs. It is a laminar flow in a a transient mode with inlet boundary condition to velocity.
Hope it helps.
Cheers,
http://www.comsol.com/model/flow-past-a-cylinder-97
Hi there,
I would have to take a look at your script but in principle it should work. Sometimes COMSOL has a bug and redoing the model from scratch solves the problem.
Nevertheless, my suggestion would be for you to take a look at a model (attached) and just adapt it to your needs. It is a laminar flow in a a transient mode with inlet boundary condition to velocity.
Hope it helps.
Cheers,
http://www.comsol.com/model/flow-past-a-cylinder-97
Thank you Joao, I learned great lessons from the tutorial, thank you again!
You are mostly welcome. Fell free to contact me if more help is required.
Cheers
Hi Joao
I am working on another model. estimating the lift, and drag car body
I looked at flow around cylinder but still I can zero drag and lift. have you had experience with this problem ? or do you have any other similar file ?
thank you
- Badges
- Science topic