Geometric correction factor $G_{corr}$ for jacket around each core

The equation for three-core cables with jacket around each core is based on the Jicable paper 'Thermal analysis of 3-core SL-type cables with jacket around each core using the IEC standard' by L.D. Ramirez et al., dated 2019.

Symbol
$G_{corr}$
Formulae
$\frac{\left(0.061 + \frac{t_{shj}}{t_{sha}}\right) \left(X_{G2} + 0.006\right) \left(a_{shj} \rho_{shj}^{2} + b_{shj} \rho_{shj} + c_{shj}\right)}{1000}$