*5.3. Discussion*

### 5.3.1. Conventional Cases (A, B, and C)

Based on the simulation results on the conventional type conductor tabulated in Tables 2–4, the current density at the attachment point and total deformation (highest value at the tip of the blade) plot can be seen on Figure 5. Comparing the graphs, it can be seen that increasing the diameter of the conductor reduces the value of current density and the amount of deformation produced on the blade as it can be expected. Although, further inspecting the results, the di fference between the 100 mm<sup>2</sup> and the 200 mm<sup>2</sup> cross-section area was less significant (34.8%) than the di fference between the 50 mm<sup>2</sup> and 100 mm<sup>2</sup> (101.9%). Increasing the diameter of the conductor implied better results or lower values, although it was not linear compared to the change in diameter. Evaluating the results leads to the assumption that the 100 mm<sup>2</sup> cross-section area produced the best results among the tested values according to the given LPL, considering the weight and cost of the usable material. Similar correlations can be seen on the graphs from the rest of the results in Figure A1 (Appendix A).

**Figure 5.** Current density (**left**) and total deformation of the blade (**right**) for the conventional case studies.

### 5.3.2. Hybrid Cases (D, E, and F)

As shown in Figure 6, the graphical representation of the simulation results can be seen for Case E.

**Figure 6.** Graphical simulation results, hybrid design (case study E); (**a**) current density in the conductor, (**b**) temperature generated by current, (**c**) deformation caused by temperature.

Based on the data tabulated in Tables 5–7, Figure 7 plotted the different current densities at different points comparing three different hybrid cases. When diameters increased, the current density reduced in the conductor as well as heating and deformation in the blade. On the other hand, at the joints of the two types of conductor, there was still an increment that could still be seen. Comparing the values of the three designs indicates that the tip only version reduces the effects of the stroke at the attachment point the least, although increasing the length of the higher diameter conductor reduces the current density at both the attachment point and at joint. The increase in current density between the attachment point and the joint, for case D, case E, and case F with 148.9%, 145.2%, and 303.5%, respectively, thus the possible damage due to the current flowing in the down conductors. This suggests that the most efficient way to improve the LPS would be to increase the overall diameter of the whole conductor.

**Figure 7.** Current density of hybrid case studies.

As shown in Figure 8, on the left, the maximum temperature of the blade, which was measured at conductor joints and on the right the total deformation caused on the blade, where the highest measured value was at the tip of the blade. It shows that there was no significant reduction in temperature and deformation between the 2 m and 5 m type (8% for temperature and 11.4% for deformation), although, the maximum temperature point moved from the area of attachment point to the joints of the two conductor. Comparing the three tested designs' results, the 2 m long conductor is suggested to be the most sufficient of all, considering the amount of material involved and the improvement in temperature, thus reduction in deformation too. The rest of the results can be seen in Figure A2.

**Figure 8.** Maximum temperature (**left**) and total deformation of the blade (**right**) for the hybrid case studies.

### 5.3.3. Conventional and Hybrid

As shown in Figure 9, on the left, the maximum temperature of the blade, meanwhile on the right, the total deformation caused on the blade, where the highest measured value was at the tip of the blade. It can be seen that both the B and E cases performed better compared to the minimal conductor cross-section area in terms of temperature increment and blade deformation. For LPL 0, the temperature difference between Case B and A was 459.67 ◦C (307.86%), meanwhile between Case E and A it was 371.83 ◦C (156.79%), furthermore, the temperature difference between Case B and E is 87.74 ◦C. Furthermore, the temperature increase is linearly proportional to the deformation and the changes for deformation are nearly identical.

**Figure 9.** Maximum temperature (**left**) and total deformation (**right**) of the blade at A, B, and E case studies.

Comparing Cases B and E, the results showed that Case B suggests the most effective conductor design in terms of temperature and displacement, also the other measured parameters.
