Performance of LI-1542 Reusable Surface Insulation System in a Hypersonic Stream
Abstract
The thermal and structural performance of a large panel of LI-1542 reusable surface insulation tiles was determined by a series of cyclic heating tests using radiant lamps and aerothermal tests in the Langley 8-foot high- temperature structures tunnel. The test panel was designed by Lockheed Missiles and Space Company to represent a portion of the Space Shuttle Orbiter fuselage along a 1100 K isotherm. Aerothermal tests were conducted at a free-stream Mach number of 6.6, a total temperature of 1830 K, Reynolds numbers of 2.0 and 4.9 X 106 per meter, and dynamic pressures of 29 and 65 kPa. The results strongly suggest that pressure gradients in gaps and flow impingement on the header walls at the end of longitudinal gaps are sources for increased gap heating. Temperatures higher than surface radiation equilibrium temperature were measured deep in gaps and at the header walls. Also, the damage tolerance of the LI-1542 tiles appears to be very high. Cracks in the tile coating and craters from foreign particle impact had no apparent effect on tile integrity. Tile edge erosion rate was slow; however, hot gas impingement on the header walls caused excessive erosion, which could not be tolerated in a Shuttle application. Tiles soaked with water and subjected to rapid depressurization and aerodynamic heating showed no visible evidence of damage. Thermodynamics and Combustion Hypersonic Thermal Protection Surface Insulation
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1974
- Accession Number
- ADA279182
Entities
People
- Herman L. Bohon
- L. Roane Hunt
Organizations
- National Aeronautics and Space Administration