I understand what you mean about it being simpler, but I tend not to work in 1D, because it can be misleading. You've got combinations of even-order and odd-order terms that don't make much sense to me if you think about them in higher dimensions. Using \nabla instead of (\partial / \partial x) makes it a bit clearer whether you're working with vectors or scalars.
If u and w are scalars, then (\partial u/partial x) is a vector and it doesn't make any sense to add (\partial^4 w\partial x^4), a scalar, to (\partial u/\partial x)(\partial^2 w / \partial x^2), a vector. On Feb 10, 2015, at 12:20 AM, Kyle Briton Lawlor <klawlor...@gmail.com> wrote: > Hello, FiPy. > > I am presently working with a set of coupled 1D pde’s. > Images with the equations are attached at the bottom of the email. > The first image shows the equations. > The second image shows the equations with a “sketch” of how I might write the > terms in FiPy and some questions I have. > > Roughly, the equations are solving for displacements of a line subject to > compressive stress. > Eventually I would like to model the two-dimensional problem. > However, I figure 1D is a good starting point as the 1D eq’s are quite > complicated themselves. > Hopefully it is feasible to solve the 1D problem in FiPy. > In the paper I’m referencing for these evolution equations, they solve using > a finite difference method. > > The two main variables in the problem as you can see in the pde’s are w and u. > w is the lateral displacement and u is the on-axis displacement. > As you can see in the equations, there are quite complicated coefficients on > a few of the terms. > Also there are two terms in particular that I am not sure how to write. (See > the second image; Term 1 and Term 2). > > I have not started coding up this problem, but I think some preliminary > guidance could be useful. > This is a broad question but is solving these equations with FiPy feasible? > > Look forward to hearing responses. > > Thanks, > Kyle > <Screen Shot 2015-02-09 at 11.59.39 PM.png> > <Screen Shot 2015-02-09 at 11.59.58 PM.png> > _______________________________________________ > fipy mailing list > fipy@nist.gov > http://www.ctcms.nist.gov/fipy > [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ] _______________________________________________ fipy mailing list fipy@nist.gov http://www.ctcms.nist.gov/fipy [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ]
