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Posted:
1 decade ago
2011/07/22 8:36 GMT-4
What you have to do is integrate a boolean expression such as T>50[degC] (which is 1 if true and 0 otherwise) over the domain of interest (that "surface" you speak of).
There are two ways to achieve this. Either you simply integrate the expression in post-processing (Results -> Derived Values). Or, slightly more complicated but offering more flexibility, you first define an integration operator for the domain (under the Model -> Defintions node) and then evaluate that operator using a Global Expression in post-processing.
What you have to do is integrate a boolean expression such as T>50[degC] (which is 1 if true and 0 otherwise) over the domain of interest (that "surface" you speak of).
There are two ways to achieve this. Either you simply integrate the expression in post-processing (Results -> Derived Values). Or, slightly more complicated but offering more flexibility, you first define an integration operator for the domain (under the Model -> Defintions node) and then evaluate that operator using a Global Expression in post-processing.
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Posted:
1 decade ago
2011/07/25 4:25 GMT-4
Thanks John, you've helped me a lot :)
Thanks John, you've helped me a lot :)
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Posted:
7 years ago
2017/06/02 5:19 GMT-4
Updated:
7 years ago
2017/06/02 5:34 GMT-4
What you have to do is integrate a boolean expression such as T>50[degC] (which is 1 if true and 0 otherwise) over the domain of interest (that "surface" you speak of).
There are two ways to achieve this. Either you simply integrate the expression in post-processing (Results -> Derived Values). Or, slightly more complicated but offering more flexibility, you first define an integration operator for the domain (under the Model -> Defintions node) and then evaluate that operator using a Global Expression in post-processing.
Hi,
Do you know by any change what will be the parameter to calculate this area? In my case I used:
if(T>Tvap, 2*dom,0) under the surface integral but the resulted area isn't what I would expected. Instead of dom what other variable is used for surface area calculation in Comsol 5.2a?
Thank you.
Edit:
I figured it out and it seems that the formula I used is right but please feel free to make any comments.
[QUOTE]
What you have to do is integrate a boolean expression such as T>50[degC] (which is 1 if true and 0 otherwise) over the domain of interest (that "surface" you speak of).
There are two ways to achieve this. Either you simply integrate the expression in post-processing (Results -> Derived Values). Or, slightly more complicated but offering more flexibility, you first define an integration operator for the domain (under the Model -> Defintions node) and then evaluate that operator using a Global Expression in post-processing.
[/QUOTE]
Hi,
Do you know by any change what will be the parameter to calculate this area? In my case I used:
if(T>Tvap, 2*dom,0) under the surface integral but the resulted area isn't what I would expected. Instead of dom what other variable is used for surface area calculation in Comsol 5.2a?
Thank you.
Edit:
I figured it out and it seems that the formula I used is right but please feel free to make any comments.
Walter Frei
COMSOL Employee
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Posted:
7 years ago
2017/06/02 10:26 GMT-4
Hello,
You may also be interested in the timeint and timemax operators ( see section on Operators, Functions, and Constants in the COMSOL Multiphysics Reference Manual)
For example, you could plot:
timemax(0,30[s],T) which will show the maximum temperature that is achieved over the first 30 seconds.
or:
timeint(0,30[s],(T>400[K])) will compute and plot how long a particular region is held above 400K in the first 30 seconds.
Hello,
You may also be interested in the timeint and timemax operators ( see section on Operators, Functions, and Constants in the COMSOL Multiphysics Reference Manual)
For example, you could plot:
timemax(0,30[s],T) which will show the maximum temperature that is achieved over the first 30 seconds.
or:
timeint(0,30[s],(T>400[K])) will compute and plot how long a particular region is held above 400K in the first 30 seconds.