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How to find gradient in COMSOL 4.1
Posted 9 janv. 2011, 14:29 UTC−5 Version 4.1 1 Reply
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I want to write my own equation in "derived value" expression field. What function should I use to find 'Grad' of a function.
1 Reply Last Post 10 janv. 2011, 03:48 UTC−5
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Posted:
1 decade ago
Hi
it depends on which variable, COMSOL has many internal derivatives defind (note the varible notation if u,v,w are dependent variables ux is du/dx, ut = du/dt, utt=d^2u/dt^2 etc. There is no GRAD operator, but you can wrie it out fully with the (ux,uy,uz)
Check the doc, perhaps the 3.5a doc is still more complete on this, or take some of the books , the one of Zimmermann is my preferred for learning how to do math/equation writin with COSMOL
At least read the 4.1 doc aoround p 100 of the user manual on the variables
--
Good luck
Ivar
it depends on which variable, COMSOL has many internal derivatives defind (note the varible notation if u,v,w are dependent variables ux is du/dx, ut = du/dt, utt=d^2u/dt^2 etc. There is no GRAD operator, but you can wrie it out fully with the (ux,uy,uz)
Check the doc, perhaps the 3.5a doc is still more complete on this, or take some of the books , the one of Zimmermann is my preferred for learning how to do math/equation writin with COSMOL
At least read the 4.1 doc aoround p 100 of the user manual on the variables
--
Good luck
Ivar