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Dear ivar, heat transfer and volume fraction coupling.

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Dear ivar, i am a comsol 4.0 user

and i want to couple the transient heat transfer and volume fraction below



Transient 1-D heat transfer : rho*cp*(dT/dt)=d/dx(k*(dT/dx))+Source term-rho*latentheat*(df/dt)

f : liquid fraction from PDE module

PDE : df/dt=f*gamma(T)



I took the source term value in Transient 1-D heat transfer "-rho*latentheat*(df/dt)" as

-rho*latentheat*ft

and In PDE module I took all zeroes in the spatial derivatives.

but it was not the data I expected.(especially, there was no difference between only Heattransfer and Heat transfer and PDE coupling)

please help..

any comment will be very appreciated . Thank you!

1 Reply Last Post Apr 18, 2011, 7:38 a.m. EDT
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago Apr 18, 2011, 7:38 a.m. EDT
Hi

I'm not sure I'm catching everything, and you are in a physics mode I not that familiar with.

What I can say though is that if "f" is defined as a "dependent variable" for a particular "physics", and you are solving in transient mode (hence including "t") then "ft" = df/dt is indeed the time derivative of f, just like "fx,fy,fz" are the components of the spatial derrivatives of "f" (in 3D as all might not apply for your case)

--
Good luck
Ivar
Hi I'm not sure I'm catching everything, and you are in a physics mode I not that familiar with. What I can say though is that if "f" is defined as a "dependent variable" for a particular "physics", and you are solving in transient mode (hence including "t") then "ft" = df/dt is indeed the time derivative of f, just like "fx,fy,fz" are the components of the spatial derrivatives of "f" (in 3D as all might not apply for your case) -- Good luck Ivar

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