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Weak form with two dependent variables
Posted 4 mar 2024, 09:48 GMT-5 Equation-Based Modeling Version 6.0 0 Replies
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Hallo, I am trying to solve a Cahn-Hilliard-equation as a weak form. I am having trouble understanding how to implement the test functions. In my case the dependet variables are c and mu. Some terms are dependent on both variables. How do I implment this in the Comsol weak form PDE? The equations are:
I) dc/dt = d/dx (Dc(1-c) dmu/dx) + a*sqrt(c(1-c))*sinh(b* mu)
II) mu = ln(c/(1-c))+ d*(1-2c)-2*k*dc^2/d^2x
with the boundary condition cx = mux = 0.
The weak form should be something like with test = test function
I) int( test* dc/dt - d test/dx*Dc(1-c) d mu/dx + test* a* sqrt(c(1-c))*sinh(b*mu))dx
II) int( test* mu - test*ln(c/(1-c)-d* (1-2c))+2 k*cx *d test/dx)dx
Thank you so much for your input!
Hello Paula Lorson
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