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How to connect in Heat transfer?

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Hello
I am working currently with “Comsol 3.5 a” and I try a heat process with the modules heat transfer to simulate. My process consists of 3 phases and each phase has different boundary conditions and hence different model. The main body is the same but the boundary conditions change every 7 seconds. I can only simulate separately each phase and would like to leave all phases converge, so the conditions at the end of the first phase as the initial conditions of the second phase and at the end of the second phase as the initial conditions of the third phase, and again from the beginning. In short, a cycle runs in 21 seconds and consists of three phases. Injection (7s) - Cooling (7s) - cast (7s).
My question is how I can connect the three phases. I would like to let the whole then run in several cycles. Thank you for any words of advice
Hervé

3 Replies Last Post Jan 6, 2010, 2:03 PM EST

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Posted: 10 years ago Nov 18, 2009, 4:10 PM EST
Hi

One way to change variables values liked to boundary conditions is to use bolean equations with the time variable "t", for example iof te tempeature of a surface is defined as T1+T2*(t>7)-T3*(t>14) you have the 3 values T1 from 0 to 7 seconds, T1+T2 from 7 to 14 and T1+T2-T3 thereafter.

Other changes such as going from fixed temperature to iolation requires further trick, and you must edit the "equations" but this discouples the GUI otrol of these variables andyouget a "lock" appearing, this is a waning ind is fully OK so long you understand what you are doing

Hope this helps
Good luck
Ivar
Hi One way to change variables values liked to boundary conditions is to use bolean equations with the time variable "t", for example iof te tempeature of a surface is defined as T1+T2*(t>7)-T3*(t>14) you have the 3 values T1 from 0 to 7 seconds, T1+T2 from 7 to 14 and T1+T2-T3 thereafter. Other changes such as going from fixed temperature to iolation requires further trick, and you must edit the "equations" but this discouples the GUI otrol of these variables andyouget a "lock" appearing, this is a waning ind is fully OK so long you understand what you are doing Hope this helps Good luck Ivar

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Posted: 9 years ago Nov 30, 2009, 11:07 AM EST
Great advice guys. Thanks for the help!
Great advice guys. Thanks for the help!

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Posted: 9 years ago Jan 6, 2010, 2:03 PM EST
Hello

I have a reaction diffusion problem with w as a variable, in which w_0 is given. I need the program to restart solving the problem every 30s, with the initial condition .5 w(30).
You can imagine the problem as solving for 90 days, but at day 30 you kill half of the solution and continue, then you do the same at day 60.
thank you for helping
Hello I have a reaction diffusion problem with w as a variable, in which w_0 is given. I need the program to restart solving the problem every 30s, with the initial condition .5 w(30). You can imagine the problem as solving for 90 days, but at day 30 you kill half of the solution and continue, then you do the same at day 60. thank you for helping

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