When rewriting the equation into a unitless equation, I also scale the area size onto a square defined by p1_u and p2_u. That means that I have to rescale it back to the original size when doing a gradient calculation, when doing a calculation for a function depending on the position, and when printing it (same as for all variables). I can do the first and the second part, but not the third part (rescaling before printing), after my triangulation is defined on the unitless square from (0, 0) to (1, 1), instead on the rectangle from (x0, y0) to (x1, y1).
Am Dienstag, 1. Mai 2018 22:33:19 UTC+2 schrieb Daniel Arndt: > > Maxi, > > Am Dienstag, 1. Mai 2018 13:39:58 UTC+2 schrieb Maxi Miller: >> >> I tried to make my equation unitless, in order to make calculations >> easier. For that I also had to rescale the boundaries, defined by p1 = >> Point<dim>(x0, y0) and p2 = Point<dim>(x1, y1) to p1_u = Point<dim>(0, 0) >> and p2_u = Point<dim>(1, 1). Now, when printing the results, I would like >> to scale the results back into the original size (so that my results are >> defined by p1 and p2, and not by p1_u and p2_u). How can I do that? I >> assume I have to modify the used dof_handler, but until now I have no idea >> about a possible solution. >> Thanks! >> > When you make your equations unitless, you define characteristic values > for the quantities you are considering and express the actually values as > multiples of these. This process typically results in some dimensionless > numbers that are characteristic for the problem you are solving. If you > want to get back to the "real" problem you just have to reverse this > process, i.e. multiply the unitless values by the characteristic values. > This approach to make sense normally requires something like > geometric-similarity between the problem you are considering originally and > the one you are solving on. > Can you specify what your problems are in this last step? Do you know what > you want to do conceptionally ? > > Best, > Daniel > -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
