Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Cross Section Plot parameters

Please login with a confirmed email address before reporting spam

Hi,
How do I get something like "Cross Section Plot parameters¨ in Comsol v4?. I'm just moving from V3.5 (where that menu appears in a explicit form) to 4 (where I can't find something like that).
The problem in which I'm working, is a fluid (engine oil) between parallels plates, so I need to evaluate the velocity profile along the duct.
Thanks for your help!


4 Replies Last Post Jun 16, 2010, 1:45 a.m. EDT
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Jun 15, 2010, 1:46 a.m. EDT
Hi

there are a lot of extra plot options in V4, right clikck on the Results, and then on the 1/2/3D Plot Group and add them in

Good luck
Ivar
Hi there are a lot of extra plot options in V4, right clikck on the Results, and then on the 1/2/3D Plot Group and add them in Good luck Ivar

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Jun 15, 2010, 4:02 p.m. EDT
There is a section in the 4.0 manual called "1D, 2D, and 3D Cross-Section Point Plots". I tried this for a 1D plot, however, after specifying a range for my x values in the "Cut Point 1D" Settings, in the "Point Data" entry field, I get a COMSOL Error when attempting to plot a Point Graph of:

"Failed to evaluate expression. - Function: range -Property value: point

The range syntax is correct yet shows up in red. I suspect this is a bug, but if you can get it to work, let us know!

I am on a Mac Pro running Snow Leopard.

A work around is to define a "Cut Point 1D" data set (or your appropriate dimension) for each point, then a separate Point Plot for each Data set. Tedious, but did get the plot I wanted.

~jim~
There is a section in the 4.0 manual called "1D, 2D, and 3D Cross-Section Point Plots". I tried this for a 1D plot, however, after specifying a range for my x values in the "Cut Point 1D" Settings, in the "Point Data" entry field, I get a COMSOL Error when attempting to plot a Point Graph of: "Failed to evaluate expression. - Function: range -Property value: point The range syntax is correct yet shows up in red. I suspect this is a bug, but if you can get it to work, let us know! I am on a Mac Pro running Snow Leopard. A work around is to define a "Cut Point 1D" data set (or your appropriate dimension) for each point, then a separate Point Plot for each Data set. Tedious, but did get the plot I wanted. ~jim~

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Jun 15, 2010, 4:33 p.m. EDT
Hi,
I've finally solved my problem (I don't know if it's the best way to do it):
1) I defined a "Cut Line 2D" in Data sets. In "Line Data", I used the "Two points" method, and I put a vertical line near the entrance and others downstream. (I defined 9 cut lines)
2)Then, I defined this "Line Graph" (9 in this case), and I selected, in "Data Set", a line defined previously.

I did the same in V3.5, but automatically.
Hi, I've finally solved my problem (I don't know if it's the best way to do it): 1) I defined a "Cut Line 2D" in Data sets. In "Line Data", I used the "Two points" method, and I put a vertical line near the entrance and others downstream. (I defined 9 cut lines) 2)Then, I defined this "Line Graph" (9 in this case), and I selected, in "Data Set", a line defined previously. I did the same in V3.5, but automatically.

Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Jun 16, 2010, 1:45 a.m. EDT
Hi

I believe so to, but there is a principle one needs to learn, have not seen it documented as such:
in V4 everything you define high up in the model tree (close to the top title) is filled in more or less automatically for you furthe down in the branches.

This means that if you define a "Probe" in the Model Definitions, it would automatiacally generate your plots when you solve (this is more or less through, COMSOl must understand what to do w.r.t. the variables you define.

This applies rather systematically through the model tree for other items too, i.e. selection lists, solver sequences ...

If you define your extra plot solely in the "Results" section they get easily erased if you delete the solution they are lined to.

This is based on the logic (I interprete) as that the model tree is to be read top down, even if, when you define it and set up your model you jump up and down sometimes

Have fun Comsoling
Ivar
Hi I believe so to, but there is a principle one needs to learn, have not seen it documented as such: in V4 everything you define high up in the model tree (close to the top title) is filled in more or less automatically for you furthe down in the branches. This means that if you define a "Probe" in the Model Definitions, it would automatiacally generate your plots when you solve (this is more or less through, COMSOl must understand what to do w.r.t. the variables you define. This applies rather systematically through the model tree for other items too, i.e. selection lists, solver sequences ... If you define your extra plot solely in the "Results" section they get easily erased if you delete the solution they are lined to. This is based on the logic (I interprete) as that the model tree is to be read top down, even if, when you define it and set up your model you jump up and down sometimes Have fun Comsoling Ivar

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.