Discussion Forum

Hi there, have you tried this? .... (see picture)

I did and that's when I see what is attached to this message. This is not the same as what is shown in the manuals.

Sirisha

Hi

that is because we are talking about two different "equation" sets
i) the underlying equations used by COMSOL (options preferences equations or triangle in window + show equations) and
ii) the main physics equations that have appeared in the v4.1 (for almost all cases) that are in the main view (physics subnode) first entry, but usually closed so you need to "open" these section of the physics subnode view

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Good luck
Ivar

Thanks Ivar! But I don't see the option that you are talking about (options->preferences->equations).

I am attaching an image file of the options I have.

I already selected the "show equation view" and I still don't see the equations as shown in page 344/345 (image attached to one of the earlier discussions in this thread) of the user's guide. This particular page talks about equation form and I don't see what I need to do to activate this equation form.

I am wondering if this is something that is supposed to be a part of a future version and it accidentally made its way into the version 4.1 manual or is there something wrong with my installation?

Thanks for the help.

Sirisha

Hi

yes you have th equation "view" on and you get the new sub-node "equations" from what I see.

But from the firstdoc images you are in the physics node (one level higher in the model tree) and there in the first tab/line you have the physics global equation (in v4.1 and for most physics)

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Good luck
Ivar

Ivar,

I am sorry about the confusion but what I want to see is .........

The manual shows a 'del' operator on page 344 and 345 and the equations shown are similar to what is shown in textbooks. What I see on my computer are just variables and weak expressions and even these have to be re-written on a piece of paper for me to understand what exactly they are.

Also, even though I am using the same physics as shown in the manual, I don't see the del operator and I also don't see the global equation.

Please upload a picture of how you are seeing the global equation.

Thanks,
Sirisha

PS: The manual also talks about an option called "show equation assuming". I cannot locate this option in version 4.1. Do I need to install the update to get all these options?

Hi

I beleive I understand what you are looking for, and what I'm saying is that you are not looking at the right place:
the "equation view" are the underlayig COMSOL variables, weak expressions etc, that are often handy to look at, but you are looking for the physics equations that are in the phyiscs node and NOT the underlaying and lowest sub-node "equation view node". These physics equations appeared (again) in V4.1 for most physics.

If you select the fig 8.1 p344 User manual v4.1:
Model 1 - Heat tranfer in solids
and you "open" the "Equation" tab (not sub-node) in the settings window you will see the equations

If you have several solvers then COMSOL does not know which equatios to show, as these changes depending on the solver you are using so you must first select then the solver you are referring to, then you will get th view up.

The confusion in fig8.2 probably comes from the fact that the "settings" views with the equations are those of the Heat Transfer node but related to the Study 1 solver settings and anre not down in the different "Solver" nodes

is it clearer ;) ?


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Good luck
Ivar

:D Thank you Ivar! That helps. Somehow I missed the equations tab in the physics node.

Sirisha