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Rectangle function
Posted 02.04.2012, 22:04 GMT-4 Heat Transfer & Phase Change 1 Reply
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Good afternoon.
I am making a model using heat transfer in solids module, where I have a bar divided with some finite elements.
The model is 2D, and over from one element, I have heat flux, and on the next six elements,
I have no convective cooling. The other elements have convective cooling.
The problem is, when the heat flux element get a temperature of 350 K, I need to change the heat flux
to the next element, besides change elements without convective cooling too (the same configuration at the
begining of simulation).
One way that I found how to do this is by using rectangular functions, where in a determined time, I change the elements. But the result with this metodology is very weak, because the temperature never stops with 350 K.
So, the question is: can I work with rectangular function using temperature, instead of time?
I tried to use analytics functions, but I cant know how is the temperature profile with the time.
There is another way to do this?
Best regards
Gabriel Tortola Flores Vieira
Ps: sorry about my english. I am from Brazil, and I am not a fluent speaker.
I am making a model using heat transfer in solids module, where I have a bar divided with some finite elements.
The model is 2D, and over from one element, I have heat flux, and on the next six elements,
I have no convective cooling. The other elements have convective cooling.
The problem is, when the heat flux element get a temperature of 350 K, I need to change the heat flux
to the next element, besides change elements without convective cooling too (the same configuration at the
begining of simulation).
One way that I found how to do this is by using rectangular functions, where in a determined time, I change the elements. But the result with this metodology is very weak, because the temperature never stops with 350 K.
So, the question is: can I work with rectangular function using temperature, instead of time?
I tried to use analytics functions, but I cant know how is the temperature profile with the time.
There is another way to do this?
Best regards
Gabriel Tortola Flores Vieira
Ps: sorry about my english. I am from Brazil, and I am not a fluent speaker.
1 Reply Last Post 03.04.2012, 03:10 GMT-4
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Posted:
1 decade ago
Gabriel,
maybe you could use boolean expressions in your heat flux definition. One example:
the expression Q1 + Q2*(T>350) gives a heat flux Q1 for temperature up to 350 deg and Q1+Q2 above 350 deg. Of course you can form more complex expressions. You can apply expressions like that to boundaries and domains.
Cheers
Edgar
maybe you could use boolean expressions in your heat flux definition. One example:
the expression Q1 + Q2*(T>350) gives a heat flux Q1 for temperature up to 350 deg and Q1+Q2 above 350 deg. Of course you can form more complex expressions. You can apply expressions like that to boundaries and domains.
Cheers
Edgar