Concept of Non-Ablative Thermal Protection System for Hypersonic Vehicles

In order to reduce the shock-wavedrag andaerodynamic heating of hypersonic vehicles effectively a newconcept of non-ablative thermal protection system was proposed based on the idea of flowfield reconstruction. In this non-ablative thermal protection system a spike-blunt body structure and lateral jets are combined together to realize the flowfieldmodification. The spike transforms the bow shock into a conical shock, and the lateral jets increase the angle of conical shock wave and keep it away from the blunt body to avoid severe shock/shock interactions. Flow visualizations and pressure measurements were conducted in a hypersonic wind tunnel at Mach number 6 to demonstrate this concept. Numerical simulations were also carried out. Both experimental and numerical results demonstrate that the non-ablative thermal protection systemworks well for shock-wave drag reduction and thermal protection. The peak pressure at the reattachment region is reduced by 65 % even under 4 deg attack angle by the lateral jet. Experimental data also show that the working pressure of lateral jets is much lower than that of forward-facing jets at the stagnation point. All the results show that the engineering application of non-ablative thermal protection system appears to be quite promising. I