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upper limit
Posted 07.01.2010, 11:25 GMT-5 3 Replies
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Hi everybody, i wuold be very pleased to know how i can assign an upper limit to the degrees of freedom.
Thanks in advance,
Luigi
Thanks in advance,
Luigi
3 Replies Last Post 21.02.2016, 07:55 GMT-5
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Posted:
1 decade ago
Hi
I'm not sure I understand you right, but for me the DoF's are the product of number of elements times number of dependent variables times the element order. As these are mostly constant once you have defined your model and finished your mesh I have some difficulties to follow what you want.
To define the number of mesh elements: it's playing with the mesh variables, and perhaps meshing by hand for a fine control of what happens. Before, you should defeature your CAD model to take away all small details requireing a lot of dense meshing, while not bringing in any relevant information for the analysis you want to do (I agree this means you must think over it and understand what is relevant, no simple automatic way around here).
If you use the adaptive meshing facility, you must play with the number of refinements and the way its done, this means further testing asthis is lso rather model dependent.
Once meshed you can find some information on the element volumes and element sizes through the "h" and "vol" variables (variable names to be completed with the application identification, see the doc).
Hope this helps
Good luck
Ivar
I'm not sure I understand you right, but for me the DoF's are the product of number of elements times number of dependent variables times the element order. As these are mostly constant once you have defined your model and finished your mesh I have some difficulties to follow what you want.
To define the number of mesh elements: it's playing with the mesh variables, and perhaps meshing by hand for a fine control of what happens. Before, you should defeature your CAD model to take away all small details requireing a lot of dense meshing, while not bringing in any relevant information for the analysis you want to do (I agree this means you must think over it and understand what is relevant, no simple automatic way around here).
If you use the adaptive meshing facility, you must play with the number of refinements and the way its done, this means further testing asthis is lso rather model dependent.
Once meshed you can find some information on the element volumes and element sizes through the "h" and "vol" variables (variable names to be completed with the application identification, see the doc).
Hope this helps
Good luck
Ivar
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Posted:
1 decade ago
Many thanks for your reply. I admit that my question was not "well posed".
I was refferring to the possibility of imposing an upper limit to the "dependent variables". In my case i have a temperature field in which some values go higher than the temperature assigned at the inflow, without any internal production or thermal flow from outside. You know it's not physical and i think it's due to numerical approximations. I have tried to do "finer" simulations but without any success. That's why...
Luigi
I was refferring to the possibility of imposing an upper limit to the "dependent variables". In my case i have a temperature field in which some values go higher than the temperature assigned at the inflow, without any internal production or thermal flow from outside. You know it's not physical and i think it's due to numerical approximations. I have tried to do "finer" simulations but without any success. That's why...
Luigi
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Posted:
9 years ago
Many thanks for your reply. I admit that my question was not "well posed".
I was refferring to the possibility of imposing an upper limit to the "dependent variables". In my case i have a temperature field in which some values go higher than the temperature assigned at the inflow, without any internal production or thermal flow from outside. You know it's not physical and i think it's due to numerical approximations. I have tried to do "finer" simulations but without any success. That's why...
Luigi
Hi Luigi,
I met the similar case to yours and need to set a limit for dependent variable. Could you please tell me how to do it? Thanks very much.
Yuhong