Table 4 Errors and CPU performance of the BDF2-nonlinear scheme by using \(\pmb{(P_{1}b, P_{1}, P_{1}dc)}\) finite element for \(\pmb{T=0.1}\) and \(\pmb{\triangle t=0.1h^{2}}\)

1/ h

\(\boldsymbol{\vert \!\vert \!\vert e_{\sigma} \vert \!\vert \!\vert _{\infty,0}}\)

\(\boldsymbol{\vert \!\vert \!\vert e_{\sigma} \vert \!\vert \!\vert _{0,0}}\)

\(\boldsymbol{\Vert e_{\mathbf{u}} \Vert _{\infty,0}}\)

\(\boldsymbol{\vert \!\vert \!\vert \nabla e_{u}\vert \!\vert \!\vert _{0,0}}\)

\(\boldsymbol{\vert \!\vert \!\vert e_{p}\vert \!\vert \!\vert _{0,0}}\)

CPU