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Equation Modeling Problem - div(u)^2

Posted Sep 22, 2015, 4:41 p.m. EDT Version 4.3 0 Replies

Diego Lopes
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Hi everyone! I need to insert a weak form over a domain in my model, the variational form is:

F(u) = 0.5*integral-over-omega((a+i*b)*(div(u)^2)domega)

I'm using the cylindrical coordinate system so my weak form is:

weak = (2*pi*r)(0.5)*(a+i*b)*((-ur*test(ur)-uz*test(uz)-u/r))^2

But unfortunately I got the message error:

"Test functions cannot be evaluated; only Jacobian is well defined."

I don't know to much about weak forms, but i think that the problem is the two exponent over a test function. How can I do div(u)^2 using the weak syntax?

I will be grateful if someone can send me this information.

Diego Soares Lopes.
0 Replies Last Post Sep 22, 2015, 4:41 p.m. EDT
COMSOL Moderator

Hello Diego Lopes

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