| Scheme | Grids | L1 error | L1 order | L∞ error | L∞ order |
| P1 | 40 | 7.7464 × 10−4 | —— | 6.0693 × 10−4 | —— |
|
| 80 | 1.9424 × 10−4 | 1.9961 | 1.5255 × 10−4 | 1.9926 |
|
| 160 | 4.6004 × 10−5 | 2.0784 | 3.6124 × 10−5 | 2.0786 |
|
| 320 | 1.1500 × 10−5 | 2.0005 | 9.0394 × 10−6 | 1.9993 |
|
| 640 | 3.0174 × 10−6 | 1.9306 | 2.3641 × 10−6 | 1.9349 |