Laplacian test cases with Dirichlet boundary conditions in the 2D axisymmetric coordinate system.
The aim of this test case is to validate the discretization of the diffusive term of a cell advection/diffusion equation in the 2D axisymmetric coordinate system.
Domain is rectangular, its opposite corner coordinates being \((0,0)\) and \((1,1)\).
We solve \(-\Delta T=f\) on the whole domain.
Using cylindrical coordinates, 2D solution of the problem is set to \(\cos(\pi r)\sin(\pi y)\). Right-end-side f is equal to \(2\pi^{2}\cos(\pi r)\sin(\pi y) + \dfrac{\pi}{r}\sin(\pi r)\sin(\pi y)\).
The symmetry axis is in located on the left at \( r=0.5 \). The global boundary conditions are chosen as follows.
Boundary | Condition | Value |
---|---|---|
Top | Dirichlet | \( T = 0 \) |
Bottom | Dirichlet | \( T = 0 \) |
Other Boundaries | Neumann | \( \partial T = 0 \) |
Energy equation is used:
Second order spatial convergence is expected.
The grid size starts from 40 in every direction to 640. Second order convergence is observed with \(L_\infty\), \(L_1\) or \(L_2\) norms.
2D results
Mesh | Temperature Linf error | Order | Temperature L1 error | Order | Temperature L2 error | Order |
---|---|---|---|---|---|---|
40 | 8.55732636e-04 | n/a | 2.69430910e-04 | n/a | 3.52892413e-04 | n/a |
80 | 2.14068698e-04 | +1.9991 | 6.73389943e-05 | +2.0004 | 8.81932983e-05 | +2.0005 |
160 | 5.35256476e-05 | +1.9998 | 1.68319461e-05 | +2.0002 | 2.20464624e-05 | +2.0001 |
320 | 1.33819414e-05 | +1.9999 | 4.20792332e-06 | +2.0000 | 5.51149922e-06 | +2.0000 |
640 | 3.34551808e-06 | +2.0000 | 1.05197011e-06 | +2.0000 | 1.37786755e-06 | +2.0000 |