Checkerboard Error Eliminated by Mesh Adaptation:
Figure 5.24 shows the Cp contours of a flow over a Jukowsky airfoil
computed by a leastsquares finiteelement scheme for the CauchyRiemann
system of velocities. A typical checkerboard error can be seen.
The scheme is based on the residual over the quadrilateral element with
solution values stored at nodes; such a scheme is suseptible to the checkerboard
error (a highfrequency mode is transparent to such a residual).
Figure 5.26 below shows the Cp contours obtained by mesh adaptation: nodes were
moved to minimize the residuals simultaneously computing the solution.
It converged rapidly, resulting in a mesh with checkerboard pertubation.
Implication is that a bad mesh can be a good mesh for a
bad scheme.
See [ PhD Thesis ], Section 5.2.5, page 115, for more details.

