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anonymousbach April 3, 2015 09:37

Boundary Conditions Question
 
I'm trying to solve an unsteady thermal diffusion problem, where a flat plate at 0 C has one end immersed in 25 C water. The boundary condition at the immersed end (x=0) is given by

-λ(∂T/∂x)=h(Tinf-T(0,t))


where h and λ are known (Presumably T(0,t=0) can be assumed to be 0 C)

Here is where I am lost, I am not sure how to implement this boundary condition in my TDMA matlab code. Would it be reasonable to make the assumption that the temperature at x=0 immediately goes to steady state? Or is there a way to solve the PDE directly?

Any help would be greatly appreciated

shahrooz.omd April 3, 2015 11:01

you don't need to specify the temperature at immersed end. you need to discretize your boundary equation using one-way differencing for (∂T/∂x) then you have aW, aP, aE, Sc, Sp. (either aW or aE will be zero depending on the boundary location)


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