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non-isothermal flow issue
Posted Jun 1, 2011, 12:46 a.m. EDT Fluid & Heat Version 4.1 1 Reply
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Hi,
I am trying to model a convection cell.
As I attached, you could see my implementation. Ra = 1e5 which creates a moderate convection cell.
I tried to run many times but, I can not make a convection cell. It just shows some strange temperature distribution.
Please help me if you have any idea to deal with this issue.
Thank you.
I am trying to model a convection cell.
As I attached, you could see my implementation. Ra = 1e5 which creates a moderate convection cell.
I tried to run many times but, I can not make a convection cell. It just shows some strange temperature distribution.
Please help me if you have any idea to deal with this issue.
Thank you.
Attachments:
1 Reply Last Post Jun 1, 2011, 2:13 a.m. EDT
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Posted:
1 decade ago
Hi
A few comments:
1) you should patch your version to latest update (or better get hands on 4.2, ask your rep) as these physics have been drastically improved in stability
2) to remember less physical constants, COMSOL has many now "built in" their names ends with "_const", such as g_const = 9.81...[m/s^2] etc
3) have you checked our initial conditions, I believe you have an issue with your pressure, and perhaps a conflict between the pressure fixing point and the initial value. But that might not be all, or I might have misunderstood your model
To quickly test out the initial conditions: right click the solver "Dependent variables #" node and right-click Compute to selected, then check your graphs
--
Good luck
Ivar
A few comments:
1) you should patch your version to latest update (or better get hands on 4.2, ask your rep) as these physics have been drastically improved in stability
2) to remember less physical constants, COMSOL has many now "built in" their names ends with "_const", such as g_const = 9.81...[m/s^2] etc
3) have you checked our initial conditions, I believe you have an issue with your pressure, and perhaps a conflict between the pressure fixing point and the initial value. But that might not be all, or I might have misunderstood your model
To quickly test out the initial conditions: right click the solver "Dependent variables #" node and right-click Compute to selected, then check your graphs
--
Good luck
Ivar