**5. Future work**

The future work has optimised the aerothermodynamic efficiency for future experimental tests and can now generate stagnation point temperatures in excess of 3000 K. The two major improvements that are associated with the Next Generation Experimental Model (NGEM) include: (a) reducing the heat losses by conduction on heatshield sample by incorporating a thermal barrier in-between the test-sample and the backshell; and (b) incorporating six degrees of freedom in order to account for the variable angle of attacks for better manoeuvrability during reentry, descent and landing [36]. These modifications enable the NGEM to be smarter and more

*Plasma Preheating Technology for Ablation Studies of Hypersonic Reentry Vehicles DOI: http://dx.doi.org/10.5772/intechopen.100129*

#### **Figure 17.**

*SEM images after the twelfth heated with flow run in proximity of points A, B, C, D and E (back). (a) In the proximity of point A. (b) In the proximity of point B. (c) In the proximity of point C. (d) In the proximity of point D. (e) In the proximity of point E.*

practically replicates real-flight vehicles as shown in **Figure 19**. The future experimental model has been fully developed for series of ablation tests in any reliable aerospace laboratory. Future experimental tests will encourage the use of spectroscopic measurements of ablation species and spatial microstructural studies using X-ray Microtomography. Infrared pyrometers and thermo-cameras are also needed to adequately monitor the surface temperature profiles across experimental samples. The next generation experimental model is not only expected to generate a stagnation point temperature of about 3200 K under the same experimental

#### **Figure 18.**

*SEM images after sixteenth heated-with-flow run in proximity of points A, B, C, D and E (back). (a) In the proximity of point A. (b) In the proximity of point B. (c) In the proximity of point C. (d) In the proximity of point D. (e) In the proximity of point E.*

conditions, but also enables variable angle of attack for better manoeuvrability during reentry, descent and landing. These inclusions have never been attempted anywhere else and will enable the next generation models to be smarter and more practically replicate real-flight vehicles.

Some of the significant improvements in the NGEM for the purpose of improving the aerothermal capabilities of the plasma preheating technology to reliably replicate planetary reentry surface temperatures with high degree of confidence are presented in **Table 1**. This novel invention is able to accurately replicate the planetary reentry surface temperatures and any associated hypersonic flow characteristics within the boundary layer.

*Plasma Preheating Technology for Ablation Studies of Hypersonic Reentry Vehicles DOI: http://dx.doi.org/10.5772/intechopen.100129*

**Figure 19.**

*Sectional view showing improved operational capabilities for the NGEM [36]. (a) Thermophysics and heat transfer. (b) Full view of the NGEM.*


#### **Table 1.**

*Materials selection for components and parts for hypersonic/ablation experiments [36].*

**Figure 20.** *Spatial temperature profiles showing heatshield thermal spread [36].*

**Figure 20** shows the temperature profile from FEA simulation using Ansys Workbench. The contact regions in the future work have been designed to minimise conduction losses at heatshield edges (shoulder regions) using a thermal barrier material (Zirconia). The improvement of surface temperature profile for future work can be seen in **Figure 20**. The details from spatial temperature profiles for the present work have been extensively published by the author [27].
