Need help finding the right PDE coefficients of this equation

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Mohammad Monfared 2013-10-23

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关闭： MATLAB Answer Bot 2021-8-20

Hi everybody,

I can't figure out what are the coefficients of this equation in comparison with PDE toolbox parabolic equation format, any suggestion is really appreciated:

or its tensor equivalent:

Theta is a scalar and the domain is in x-z plane.

thanks,

Mohammad,

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Mohammad Monfared 2013-10-25

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Now I have better understanding of my equation. " div(-K)*del(z) " is a scalar itself so no problem with that anymore. Since K is a function of theta and d(K)/d(z) and hence, d(K)/d(theta) . d(theta)/d(z) is to be determined, there is a need to know theta at each node to complete the task, so it seems to me the right choice should be 'a' not 'f'.

a new question came to me: while assigning Neumann boundary conditions, the general form is:

n.(c*del(u)) + q*u = g

now what if 'c' in boundary condition differs from 'c' in the main PDE equation (which is my case)?

with appreciation,

Mohammad

Mohammad Monfared 2013-10-27