Geometric reference factor $G_{FEA}$ based on FEM fitting

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
$G_{FEA}$
Formulae
$- 760.75 X_{G2}^{4} + 323.985 X_{G2}^{3} - 55.8292 X_{G2}^{2} + 7.80188 X_{G2} + 0.107238$
Related
$X_{G2}$