**4. Numerical Modelling**

The numerical investigation methodology was developed using the CFD tools of the ANSYS-FLUENT software package [44]. The numerical modelling was created based on the physics principles and the investigational procedure of the problem. The NFs samples were deemed single-phase fluids and the FVM method was employed. The previously determined (reported in the previous section) thermophysical properties of the NF samples were inserted into the numerical model corresponding to each NF sample. Moreover, a second-order upwind method is chosen for the convection and diffusing matters. The pressure and velocity of each fluid flow was linked by the SIMPLE method [45]. The simulations of the numerical approach are accomplished with achieving residual errors below 10−<sup>6</sup> for the calculations of the governing equations.
