New question #107819 on DOLFIN: https://answers.launchpad.net/dolfin/+question/107819
To solve nonlinear PDE du/dt+3*lmbda*u^2*du/dx*(sina-cosa*du/dx)-lmbda*u^3*cosa*d2u/dx2=0 is the following weak form right? L = v*u*dx-v*u0*dx+dt*lmbda*v*3*u*u*u.dx(0)*(sin(alpha)-cos(alpha)*u.dx(0))*dx+dt*lmbda*u*u*u*cos(alpha)*u.dx(0)*v.dx(0)*dx a = derivative(L, u, du) I am sure the rest code for newton's method and time steps should be right. But I got the wrong result. I notice that there is a (du/dx)^2 in the 2nd term. I guess it may cause some problems. Because if I get rid of the (du/dx)^2, the result is exactly same with my finite difference code (which should be right), If I keep it there, it's different. Anyone know why? Thank you. -- You received this question notification because you are a member of DOLFIN Team, which is an answer contact for DOLFIN. _______________________________________________ Mailing list: https://launchpad.net/~dolfin Post to : [email protected] Unsubscribe : https://launchpad.net/~dolfin More help : https://help.launchpad.net/ListHelp
