/** # Shock reflection by a circular cylinder The evolution of an initial "step" wave is modelled using the Saint-Venant equations. The wave interacts with a circular cylinder described using embedded solid boundaries. Adaptivity is used to track the wave fronts. This example is discussed in [An and Yu, 2012](/src/references.bib#an2012). */ #include "saint-venant.h" int LEVEL = 9; /** We define a new boundary for the cylinder. */ bid cylinder; int main() { size (5.); G = 9.81; origin (-L0/2., -L0/2.); init_grid (1 << LEVEL); run(); } /** We impose height and velocity on the left boundary. */ #define H0 3.505271526 #define U0 6.29033769408481 h[left] = H0; eta[left] = H0; u.n[left] = U0; event init (i = 0) { /** The geometry is defined by masking and the initial step function is imposed. */ mask (sq(x + 0.5) + sq(y) < sq(0.5) ? cylinder : none); foreach() { h[] = (x <= -1 ? H0 : 1.); u.x[] = (x <= -1 ? U0 : 0.); } } event logfile (i++) { stats s = statsf (h); fprintf (stderr, "%g %d %g %g %.8f\n", t, i, s.min, s.max, s.sum); } /** We generate movies of depth and level of refinement. */ event movie (t += 0.0025; t <= 0.3) { output_ppm (h, min = 0.1, max = 6, map = cool_warm, linear = true, n = 400, file = "depth.mp4"); scalar l[]; foreach() l[] = level; output_ppm (l, map = cool_warm, min = 4, max = LEVEL, n = 400, file = "level.mp4"); } /** ![Animation of the fluid depth](shock/depth.mp4)(autoplay) ![Animation of the level of refinement](shock/level.mp4)(autoplay) The mesh is adapted according to the error on the height field. */ event adapt (i++) { astats s = adapt_wavelet ({h}, (double[]){1e-2}, LEVEL); fprintf (stderr, "# refined %d cells, coarsened %d cells\n", s.nf, s.nc); } /** ## See also * [Same case with Gerris](http://gerris.dalembert.upmc.fr/gerris/examples/examples/shock.html) */