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Post-processing Results
Posted 02.06.2011, 20:58 GMT-4 Modeling Tools & Definitions, Results & Visualization, Studies & Solvers Version 4.1 2 Replies
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I am very new to the COMSOL interface.. so I could really use some help.
I'm solving 16 PDE's (Coefficient form PDEs) with 16 dependent variables over a spacial 1D domain of 27 finite elements. The total number of degrees of freedom solved for is 3216 and the solution was completed in about 2 minutes. Now I have 2 issues I am unable to figure out .
1. When I view my results I can only see the plot for 1 of the dependent variables over the distance 'x'. Where can I pick the other variables that I want a plot of?
2 (And this is a little more complex). While solving the 16 PDE's, I gave the value of the source term for each of the 16 equations as zero. Now what I need to do is run an iterative loop that will make the source term for each of the equations equal to a weighted sum of the dependent variables [i.e, the sum of (a constant for each variable times the variable itself)] and solve the whole bunch of equations again. This process has to be repeated till the solutions to the variables converge ( just say for 100 iterations)
I am given to understand that both of these can be done by postprocessing on COMSOL.
Am i right? Does anyone know how to do the stuff I have just explained?
Also : I have tried to explain the problem in a way that is easiest to understand. Please reply back with any doubts you may have about my question.
Thanks.
-Nikhil Shankar
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1. When I view my results I can only see the plot for 1 of the dependent variables over the distance 'x'. Where can I pick the other variables that I want a plot of?
There should be an expression field of what to plot in your plot group. Check sub-nodes of your plot group.
2 (And this is a little more complex). While solving the 16 PDE's, I gave the value of the source term for each of the 16 equations as zero. Now what I need to do is run an iterative loop that will make the source term for each of the equations equal to a weighted sum of the dependent variables [i.e, the sum of (a constant for each variable times the variable itself)] and solve the whole bunch of equations again. This process has to be repeated till the solutions to the variables converge ( just say for 100 iterations)I personally would use LiveLink and Matlab to extract all the stuff and rerun. I haven't ever used batch processing. I'm not sure if you can get away using it.
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As for question 2, I'm not sure how to do the whole livelink with matlab process.
But before I even try that, I'd like to know - How do you define algebraic equations on COMSOL?
I need to input a simple algebraic constraint equation that should should logically solve all my problems.
Thank you.
-Nikhil