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weak form of transient heat conduction in solids

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Hello all,

I'm trying to come up with a transient weak formulation of heat conduction through solids. The equation of interest is:

rho.C.dT/dt + del(q)=Q

I have already successfully implemented the steady state part (subdomain) of the heat equation in Comsol's Physics Interface Builder as k.del(T).test(del(T)) which was verified by Comsol's "ht"-module. However, I have trouble in defining the weak equation for the transient part (rho.C.dT/dt).

rho.C.Tt gives me an error, saying Failed to evaluate variable Jacobian. - Variable: Tt
rho.C.d(T,t) does not give me any comparable solution to Comsol's "ht"-module

Does anyone know what the weak form of the above equation is?

Many thanks in advance


1 Reply Last Post 11.02.2013, 13:09 GMT-5

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Posted: 1 decade ago 11.02.2013, 13:09 GMT-5
Hi,,
I think it is just T.test times the term you mention. Time is specially dealth with in comsol weak form.
Otherwise you can formulate a model in general pde form (math) and display it in weak form later.

Best regards,
Per
Hi,, I think it is just T.test times the term you mention. Time is specially dealth with in comsol weak form. Otherwise you can formulate a model in general pde form (math) and display it in weak form later. Best regards, Per

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