Ablative performance of uncoated silicone-modified and shuttle baseline reinforced carbon composites
Abstract
The relative ablative performance of uncoated silicone-modified reinforced carbon composite (RCC) and uncoated shuttle baseline RCC substrates was investigated. The test specimens were 13 plies (5.3 to 5.8 millimeters) thick and had a 25-millimeter-diameter test face. Prior to arc tunnel testing, all specimens were subjected to a heat treatment simulating the RCC coating process. During arc tunnel testing, the specimens were exposed to cold wall heating rates of 178 to 529 kilowatts/sq m and stagnation pressures ranging from 0.015 to 0.046 atmosphere at Mach 4.6 in air, with and without preheating in nitrogen. The results show that the ablative performance of uncoated silicone-modified RCC substrates is significantly superior to that of uncoated shuttle baseline RCC substrates over the range of heating conditions used. These results indicate that the silicone-modified RCC substrate would yield a substantially greater safety margin in the event of complete coating loss on the shuttle orbiter.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- December 1976
- Bibcode:
- 1976STIN...7716291D
- Keywords:
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- Ablation;
- Carbon-Carbon Composites;
- Silicone Resins;
- Space Shuttles;
- Spacecraft Construction Materials;
- Aerodynamic Heating;
- Coatings;
- Heat Treatment;
- Oxidation Resistance;
- Phenolic Resins;
- Reentry;
- Wind Tunnel Tests;
- Fluid Mechanics and Heat Transfer