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how to couple ODE functions with temperature
Posted 5 déc. 2016, 04:16 UTC−5 Heat Transfer & Phase Change Version 5.2a 2 Replies
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Hi
Heat Transfer in Solids module and domain ODE module are used in my simulation. In Heat Transfer in Solids module, temperature is already defined. In domain ODE module, dp/dt=f(p, T), in which p is porosity and T is the average temperature of the domain.
However, if I define 2 variables p and T in ODE module, it shows 'the variable names must be unique'. I think I have seen a solution before, in which someone use 2 Studies to couple ODE with temperature. www.comsol.com/community/forums/general/thread/40597/
So can I use this method or is there any other solution? Thanks for helping!
Heat Transfer in Solids module and domain ODE module are used in my simulation. In Heat Transfer in Solids module, temperature is already defined. In domain ODE module, dp/dt=f(p, T), in which p is porosity and T is the average temperature of the domain.
However, if I define 2 variables p and T in ODE module, it shows 'the variable names must be unique'. I think I have seen a solution before, in which someone use 2 Studies to couple ODE with temperature. www.comsol.com/community/forums/general/thread/40597/
So can I use this method or is there any other solution? Thanks for helping!
2 Replies Last Post 7 déc. 2016, 08:38 UTC−5
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Posted:
8 years ago
Hi,
I think that only p should be a dependent variable in the ODE, and that, as you mention, the temperature there is an average temperature called T_avg, for example, and defined using an Average coupling operator that averages the temperature field from the Heat Transfer in Solids interface.
Best regards,
Magnus Ringh, COMSOL
I think that only p should be a dependent variable in the ODE, and that, as you mention, the temperature there is an average temperature called T_avg, for example, and defined using an Average coupling operator that averages the temperature field from the Heat Transfer in Solids interface.
Best regards,
Magnus Ringh, COMSOL
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Posted:
8 years ago
Hi Magnus,
I've built this model, and porosity decreases with time. Now the problem is that when porosity decreases from 30% to 2%, almost at the end of densification, it starts to vibrate higher and lower. But the reality is that the porosity would keep almost constant at the end.
So how can I avoid the problem in COMSOL?
I've built this model, and porosity decreases with time. Now the problem is that when porosity decreases from 30% to 2%, almost at the end of densification, it starts to vibrate higher and lower. But the reality is that the porosity would keep almost constant at the end.
So how can I avoid the problem in COMSOL?