Hello, i am trying to reimplement the diffusion solver in doyub kim's book. The code is quite long so i probably won't post it, but i see that the result has strange lines in it. They get very noticeable when the diffusion coefficient is high (possibly blew up). Just wondering if anyone come across this problem before.
The test is essentially:
def test_stable(self):
size = (160, 120, 150)
grid_spacing = (1 / size[0],) * 3
src = CellCenteredScalarGrid3(size, grid_spacing)
mp = src.bounding_box.mid_point()
def fill_func(x):
return cp.where(cp.linalg.norm(x - mp, axis=-1) < 0.2, 1.0, 0.0)
src.fill(fill_func)
data1 = src.get_data()[:, :, 75]
time_step = 0.1
diffusion_coef = (grid_spacing[0]) ** 2 / time_step / 12
diffusion_solver = GridBackwardEulerDiffusionSolver3()
target = diffusion_solver.solve(source=src,
diffusion_coefficient=1*diffusion_coef,
time_interval_in_seconds=time_step)
data2 = target.get_data()[:, :, 75]
