\(\alpha=\frac{\alpha_{\infty}}{\alpha^{*}}=\left(\frac{\alpha_{0}^{*}+\frac{\mathrm{\text{Re}}_{t}}{R_{k}}}{1+\frac{\mathrm{\text{Re}}_{t}}{R_{k}}}\right),\ \ \ \alpha_{\infty}=F_{1}\alpha_{\infty,1}+\left(1-F_{1}\right)\alpha_{\infty,2}\) (28)