Table 9 \(L_{1}\) and \(L_{\infty }\) errors and CPU time at some different values of time-step size, k for Problem 2 at time \(2.5\times 10^{-3}\) with spatial mesh size, \(h=0.01\), \(\epsilon =0.01\) using NSFD-ϵ scheme, \(T_{\mathrm{max}}=2.5\times 10^{-3}\)

\(T_{\max }/26\)

1.8636 × 10⁻¹

9.8705 × 10⁻¹

\(T_{\max }/50\)

1.2102 ×10⁻¹

9.1868 × 10⁻¹

\(T_{\max }/100\)

6.5470 × 10⁻²

6.7456 × 10⁻¹

\(T_{\max }/200\)

2.4582 × 10⁻²

2.9094 × 10⁻¹

\(T_{\max }/300\)

4.8806 × 10⁻³

5.9139 × 10⁻²

\(T_{\max }/333\)

1.0091 × 10⁻³

9.5627 × 10⁻³

\(T_{\max }/334\)

9.9448 × 10⁻⁴

1.0714 × 10⁻²

\(T_{\max }/335\)

1.0119 × 10⁻³

1.1866 × 10⁻²

\(T_{\max }/400\)

8.5987 × 10⁻³

1.0311 × 10⁻¹

\(T_{\max }/500\)

1.9385 × 10⁻²

2.2445 × 10⁻¹