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Conjugate heat transfer
Posted 14 ago 2017, 14:06 GMT-4 Heat Transfer & Phase Change Version 5.3 3 Replies
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I'm trying to model oil quenching. I have built a steel sphere which is at temperature 850°C to be quenched in a cylindrical oil bath maintained at 215°C. I assign material to the oil bath and the steel sphere, by separately selecting the two domains. But the problem occurs when I assign 'Steel' to the sphere. In the material properties window, 'dynamic viscosity' or sometimes 'Ratio of specific heats' pops up, which do not have any values for a solid material. Unless I specify these values, the material assignment is incomplete and I can't proceed further.
Please shed some light on how to correctly assign material for a steel sphere immeresed completely in an oil bath.
Regards,
Avinash
Please shed some light on how to correctly assign material for a steel sphere immeresed completely in an oil bath.
Regards,
Avinash
3 Replies Last Post 15 ago 2017, 08:27 GMT-4
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Posted:
7 years ago
Hi
probably you are not distinguishing correctly in your domains between HT solid domains and HT Fluid domains. By default COMSOL proposes either a Solid domain node or only a Fluid Domain node (depending if you have chosen HT in solid or HT in Fluids as starting point.
You must add a new Domain node with either Fluid or Solid such that you have one of both, and then select the respective domains for Solid and Fluids (all this in ONE same HT physics section.
This would arrange your material properties accordingly to their state solid or fluid.
The type of error you mention comes from a mix of solid material assigned to fluid domains and/or the contrary
--
Good luck
Ivar
probably you are not distinguishing correctly in your domains between HT solid domains and HT Fluid domains. By default COMSOL proposes either a Solid domain node or only a Fluid Domain node (depending if you have chosen HT in solid or HT in Fluids as starting point.
You must add a new Domain node with either Fluid or Solid such that you have one of both, and then select the respective domains for Solid and Fluids (all this in ONE same HT physics section.
This would arrange your material properties accordingly to their state solid or fluid.
The type of error you mention comes from a mix of solid material assigned to fluid domains and/or the contrary
--
Good luck
Ivar
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Posted:
7 years ago
Hello!
Thank you for your reply!
I wanted to point out that I had taken 'Conjugate heat transfer' in the 'Heat transfer' physics tree, I.e., Heat transfer>conjugate heat transfer>turbulent flow>turbulent flow, k-£ (read epsilon).
And I have used time dependent study. And still the problem prevails.
Regards,
Avinash
Thank you for your reply!
I wanted to point out that I had taken 'Conjugate heat transfer' in the 'Heat transfer' physics tree, I.e., Heat transfer>conjugate heat transfer>turbulent flow>turbulent flow, k-£ (read epsilon).
And I have used time dependent study. And still the problem prevails.
Regards,
Avinash
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Posted:
7 years ago
Updated:
7 years ago
Hello Avinash,
When the software is complaining that you did not provide a dynamic viscosity for a solid, that means that you have not deselected the part of the geometry occupied by the solid in the Turbulent Flow, k-
node, i.e. you are telling the software that you want the fluid flow equation solved in that part of the geometry - and that requires among other things a dynamic viscosity. Since that's not what you intended to tell the software, deselect the part of the geometry occupied by the solid from the Turbulent Flow, k- node and you'll be all set.
When the software is complaining that you did not provide a ratio of specific heats for a solid, that means that you have selected the part of the geometry occupied by the solid in the Heat Transfer > Fluid node, i.e. you are telling the software that you want that part of the geometry handled as a fluid for the purpose of heat transfer - and that requires among other things a ratio of specific heats. Make sure that in the Heat Transfer > Fluid node you select only the part of the geometry occupied by the fluid and you'll be all set.
Best,
Jeff
When the software is complaining that you did not provide a dynamic viscosity for a solid, that means that you have not deselected the part of the geometry occupied by the solid in the Turbulent Flow, k-
node, i.e. you are telling the software that you want the fluid flow equation solved in that part of the geometry - and that requires among other things a dynamic viscosity. Since that's not what you intended to tell the software, deselect the part of the geometry occupied by the solid from the Turbulent Flow, k- node and you'll be all set.When the software is complaining that you did not provide a ratio of specific heats for a solid, that means that you have selected the part of the geometry occupied by the solid in the Heat Transfer > Fluid node, i.e. you are telling the software that you want that part of the geometry handled as a fluid for the purpose of heat transfer - and that requires among other things a ratio of specific heats. Make sure that in the Heat Transfer > Fluid node you select only the part of the geometry occupied by the fluid and you'll be all set.
Best,
Jeff