Hi.
I am also facing the same problem on Comsol 4.0.
I am trying to solve unsteady fluid flow in a pipe with heat transfer, with constant inlet velocity.
When I solve using laminar model or with steady model it works. If I am using turbulent model, Comsol gives error "Failed to find consistent initial values".
After going through forums here, I understood that I need to use step function. So I used inlet velocity condition as – ‘U_mean*step1(t)’ (Umean – mean velocity and step1() is a step function ).
This hasn’t worked yet.
Please let me know if there is a better option to define inlet condition for unsteady turbulent fluid flow problem.
Thanks,
Rohan
I am also facing the same problem on Comsol 4.0.
I am trying to solve unsteady fluid flow in a pipe with heat transfer, with constant inlet velocity.
When I solve using laminar model or with steady model it works. If I am using turbulent model, Comsol gives error "Failed to find consistent initial values".
After going through forums here, I understood that I need to use step function. So I used inlet velocity condition as – ‘U_mean*step1(t)’ (Umean – mean velocity and step1() is a step function ).
This hasn’t worked yet.
Please let me know if there is a better option to define inlet condition for unsteady turbulent fluid flow problem.
Thanks,
Rohan