Hello Wolfgang, hello Mihai, > Can one > expect to get full order of convergence for the hyperbolic transport > equation? My recollection was that, for example, using the streamline > upwind method for this equation only yields order 1.5 as well.
Wolfgang, you're right. Even for smooth solutions we can only expect p+0.5 according to theory. On most meshes we obtain p+1 numerically, however. Using "Peterson-meshes" one actually obtains the reduced order. Nevertheless, this yields order 1.5 for linears, order 2.5 for quadratics, whereas Mihai reported orders 1 and 1.5. I modified step-12 in the way suggested by Mihai and obtained perfect second and third order for linear and quadratic ansatz functions, respectively. Even without the shift of the vector field the degradation of the convergence rate is negligible. Mihai, it seems that there is still some error in your code, maybe in the right hand side. This is just a guess, of course, but it is the only relevant change. If you can't fix it feel free to let me have a look. Best, Tobias _______________________________________________ dealii mailing list http://poisson.dealii.org/mailman/listinfo/dealii
