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How to add heat source as a time differential term
Posted Jun 20, 2018, 8:48 a.m. EDT Heat Transfer Version 5.3a 1 Reply
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Hi,
I am using phase change material in my heat transfer model. I treat the latent heat of the material as a heat source. The defination of the heat source is S=rhoH(latentheat)df/dt f is the liquid fraction, which is a fuction of time: f=0(T<Ts)+((T-Ts)/(Tl-Ts))(Ts<T<Tl)+1(T>Tl) where Ts is the freezing temperature and Tl is the melting temperature. f is difined as a varible f(T) firstly. In heat transfer physics, i add it as heat source: Q=rhoH*d(f(T),t) But it dosent work.
I dont know if it is because i defined the differential part wrong or the it is not possible to difine the heat source term like this?
Thank you so much!
Best regards,
Yue
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Hi,
Is your function f defined as an analytic function ? What do you mean by "it doesn't work" ? Plus you derivate it over time while there is no "t" inside of the equation, I know that the temperature T will change over time but Comsol doesn't have an analytic version of the Temperature solution (finite elements is numerical analysis) so I guess the problem is here.
Johan