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how could i difine domain

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halo all

i want to define Viscosity in one of my domains, the equation is :V=vo+250000xv0(z-z0)^2. and if i am using 2 phaes field one is for air and the second for water should i add new mode or i can difne it in sam phase field ?


thanks alot

4 Replies Last Post 02.07.2010, 18:22 GMT-4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 30.06.2010, 15:52 GMT-4
Hi

Ifit's in 3.5 (as I havent checked yet in V4) and you write correctly in COMSOL language with * it shoudl work to replace the viscuasity constant by your formula. If you also use a 2 pase field that is defined by some spatial coorinates you must multiply by some bolean equations()or perhaps the if works too) to tell where to switch from one to the other, no ?

Have fun Comsoling
Ivar
Hi Ifit's in 3.5 (as I havent checked yet in V4) and you write correctly in COMSOL language with * it shoudl work to replace the viscuasity constant by your formula. If you also use a 2 pase field that is defined by some spatial coorinates you must multiply by some bolean equations()or perhaps the if works too) to tell where to switch from one to the other, no ? Have fun Comsoling Ivar

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Posted: 1 decade ago 30.06.2010, 18:36 GMT-4
thanks Ivar , is there any documnts about how to use 'if' in comsol i am useing 3.5a


thanks again
thanks Ivar , is there any documnts about how to use 'if' in comsol i am useing 3.5a thanks again

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

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Posted: 1 decade ago 02.07.2010, 02:51 GMT-4
Hello

I beleive it's in the command.pdf, but its just the syntax, else use the boleans i.e. *(x<0) which is =0 false and 1 true (I believe)

Good luck
Ivar
Hello I beleive it's in the command.pdf, but its just the syntax, else use the boleans i.e. *(x

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Posted: 1 decade ago 02.07.2010, 18:22 GMT-4
thanks alot ...i will try it
thanks alot ...i will try it

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