Table 1: The error estimates for conforming FE scheme.

1/2 1/4 1/8 1/16 1/32 1/64

2.1780 −02 6.6596 03 1.8851 03 5.1760 04 1.3861 04 3.5405 05
order / 1.8084 1.8796 1.9084 1.9324 1.9786
5.3923 03 1.5926 03 4.1215 04 1.0371 04 2.5691 05 6.1214 06
order / 1.8401 1.9657 1.9935 2.0092 2.0486