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How to Write 2D diffusive wave equation in PDE form

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Hi all,

I want to write equation that I attached here, and I wrote it inside the comsol but I am not sure if this is the correct form of writing.
Explanation about equation: d0= depth of flow h0=water surface elevation K0(x,y)= surface conductance in x and y direction.

In some way,
I tried to write 2D diffusive wave equation in PDE in comsol, but after running my program I confronted with this error:
Attempt to evaluate nonintegral power of negative number.
- Function: ^
Failed to evaluate variable.
- Variable: mod1.ksx
- Defined as: (mod1.d^0.66666666666666663)/((mod1.trueSlopex^0.5)*mod1.nx)
Failed to evaluate expression.
- Expression: d(d((-mod1.ut*test(mod1.u)-mod1.d*mod1.ksx*mod1.ux*test(mod1.ux)-mod1.d*mod1.ksy*mod1.uy*test(mod1.uy))*(dvol),{test@4}),mod1.ux)


Does anybody know how is it possible to fix this problem,please?

Hope to hear from you.
Sepideh




0 Replies Last Post Sep 1, 2015, 11:41 a.m. EDT
COMSOL Moderator

Hello Sepideh Ramezani

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