On Fri, May 3, 2013 at 3:08 PM, Edwin Sze Lun Khoo <[email protected]> wrote:
> Hello Jonathan and Daniel, > > Thanks for the useful suggestions. What do you mean by using Newton steps > and correction variables? > I'm referring to the method used for the outer iterations (sweeps, or non-linear iterations) as opposed to the method used to the inner linear iterations, which the linear solver takes care of. There are basically two methods that are generally used. The first and least complicated to implement is Picard sweeps (also known as method of successive substitutions or fixed point iteration). This is just when the previous solution is used as the initial guess and the equations are used directly to solve for the new variable. The second method is Newton sweeps, which requires substituting the variable + correction and then solving for the first order expansion with the zero order expansion as the residual using the previous solution to calculate the residual. Maybe try searching for Newton versus Picard to get a better explanation. I thought it might be worth trying Newton for this problem because it seems like a more natural linearization of the convection term. I hope the above helps some. Cheers. -- Daniel Wheeler
_______________________________________________ fipy mailing list [email protected] http://www.ctcms.nist.gov/fipy [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ]
