High-Temperature Materials - NASA Technical Reports Server …

1 High-Temperature Materials Stan Bouslog TPS Technical Discipline Lead NASA Johnson Space Center July 2021. Outline Why High-Temperature Materials ? Industrial Uses Aerospace Vehicles Engines and Motors Hypersonic Thermal Protection Thermal Protection Systems (TPS). Different Types of TPS. Selecting a TPS. Historical TPS. Apollo Space Shuttle Orbiter TPS Now Post-Shuttle Future TPS. Questions 2. High Temperature Materials : Industrial Uses High Temperature = Temperatures > ~300 F. Energy Production Fire Protection Electronics Material Processing Ovens Inconel 718 Turbine Carbon Fiber Boards Alumina Fiber Blankets 1300 F (700 C) >3000 F in vacuum 2900 F. 3. High Temperature Materials : Aerospace Vehicles Commercial Aircraft Rocket Motors Titanium.

2 Engine compressor and nozzle Carbon cloth phenolic . engine nozzle Hypersonic Aircraft Fibrous Blankets Carbon- Carbon Inconel skin Ti Frames Ceramic Tiles X-15 Mach 6+. Orbiter Mach 25+ 4. Why Thermal Protection for Hypersonic Vehicles 10,000. 9,000. Nitrogen Assumes T =400 R. Dissociation 8,000. 7,000. Above ~Mach 5, Air Stagnation Temperature (F). 6,000 the thermal Hi-Temp Air environment 5,000. Oxygen Dissociation drives the need 4,000 for vehicle thermal 3,000. Titanium melts Steel/Inconel melts protection. 2,000. Perfect Air Aluminum melts 1,000. 0. 0 5 10 15 20 25. Mach Number Ref.: Bertin, , Hypersonic Aerothermodynamics' 5. Approaches to Thermal Protection Radiative Systems Ref: Entry Thermal Protection,'.

3 Radiate heat away from surface NASA SP-8014, Aug. 1968. Design implementation: High emittance surface Heat-Sink Systems Absorb the heat Design implementation: High specific heat Insulation Systems Slow the heat wave Design implementation: Low thermal conductivity Ablative Systems Decomposition of material absorbs heat Design implementation: Prefer charring Materials Transpiration Systems Cool the boundary layer Design implementation: Inject fluid into boundary layer from surface Active Cooling Systems Cool the surface with internal fluid Design implementation: Heat exchanger with cooling fluid 6. TPS: Radiative Systems Example: Orbiter Space Shuttle Leading Edge q = T 4. convective surface 7. TPS: Heat Sink Systems Cast Inconel Metallic Fillet Example: X-33 Metallic Fillet q = mC p tT.

4 Convective Absorb heat into material Why on X-33? Thermal growth of wing resulted in need for gap in Advanced Carbon- Carbon wing leading edge panels. Flow forced into gap was directed to surface by metallic fillet. 8. TPS: Insulation System Example: Orbiter Tiles T. k = q convection + q radiation x x =0. Radiated Convective Heating Heat Flux Radiative Heating Surface Coating Insulation Conducted Heat Flux Adhesive Carrier Structure 9. TPS: Ablative Systems Example: Apollo Heat Shield 10. TPS: Transpiration System 11. TPS: Active Cooling Example: Shuttle Main Engines qconvective Hot fluid out Cool fluid in Liquid hydrogen flows thru tubes. Cools nozzle and preheats hydrogen Brazed Stainless Steel Nozzle 12.

5 How to Select a TPS. 13. Missions Drive Environments Lunar Space Shuttle Asteroid 14. Reentry Environments Drive TPS Selection 450. 400 Single-Use Ablators 350. Lunar Radiation Heating 300. Apollo Lunar Convective Heating Heat Flux (W/cm2). 250 Missions STS-121 Entry Heating BP1101. 200. Reusable Tiles 150. 100. Shuttle 50. Missions 0. 0 250 500 750 1,000 1,250 1,500. Time (secs.). 15. But, It's More Than Reentry Heating Separation Event -Pyro shock On-Orbit - Temperature Cycles Ascent - Vacuum - Aeroheating - Atomic oxygen -Rapid pressure decrease - MMOD impact - Plume Heating - Debris impact Reentry Launch - High heating -Vibro-acoustic - Dissociated Air - Over-pressure - Debris impact Mission Sequence of Environments Landing On the Pad - Heat shield -Humidity separation - Rain - Lightning 16.

6 Other Considerations Manufacturing Processes Penetrations thru TPS. & Supply Chain OV-103. Doors Flt 27. -ET Umbilical Lost - Landing gear Elevon Tile - Hatches Windows Antennas Reaction Control Orion System Jets Shock Events Launch Abort Attachment TPS Mass WEIGHT. ET. Separation TIME PICA Failure 17. TPS Testing Radiant Heat Tests Arc-jet Tests Structural Tests Radiant Heating Structural Flexure -Variable heat Reentry Aerothermal Simulation Medium Test Articles - Variable pressure - Dissociated gas -TPS assemblies Large Test Articles Small Test Articles - TPS penetrations -TPS assemblies -TPS Materials Structural Model Validation - TPS penetrations - TPS penetrations Thermal Conductivity Thermal/chemical behavior Thermal Model Validation Thermal Response Model Validation Thermal induced deflections 18.

7 Results of Getting It Wrong X-15 Ramjet Flight Test Columbia Accident What Happened? What Happened? Burn through and Loss of vehicle near-structural and crew. failure of pylon. Why? Why? Ascent impact Underestimated damage to heating due to Carbon-carbon shock/shock leading edge. interaction. Columbia Accident Investigation Board, Aug. 2003. 19. Historical Thermal Protection Systems Good Reference Glass, David E., "Ceramic Matrix Composite (CMC) Thermal Protection Systems (TPS). and Hot Structures for Hypersonic Vehicles;"; 15th AIAA International Space Planes and Hypersonic Systems and Technologies Conference, Dayton, OH; AIAA-2008-2682;. April-May 2008. 20. Manned Spacecraft Entry Vehicles 21. Comparison of Manned Entry TPS.

8 SHUTTLE. 4/12/81 7/21/11. 135 (133) flights 11 895 FT2. 18 904 LB. Rigidized silica fibers 9-22 LB/FT3. 135 (133) FLIGHTS. 22. Apollo TPS/Structure Configuration AVCO 5026-39 HCG. (Filled Epoxy Novalac in Fiberglas-Phenolic Honeycomb). Now manufactured by Textron Heat shield Core from Apollo 11. 23. Apollo Ablator Thickness & Surface Recession Distribution 24. Physical Model of a Charring Ablator 25. Space Shuttle Orbiter TPS Configuration RCC - Reinforced Carbon-Carbon AFRSI (FIB) - Advanced Flexible Reusable Surface Insulation HRSI - High-Temperature Reusable Surface Insulation FRSI - Flexible Reusable Surface Insulation LRSI - Low-temperature Reusable Surface Insulation Penetrations - seals and thermal barriers RCC - Re-inforced Carbon-Carbon HRSI - High-Temperature Reusable Surface Insulation LRSI - Low-temperature Reusable Surface Insulation AFRSI (FIB)

9 - Advanced Flexible Reusable Surface Insulation FRSI - Flexible Reusable Surface Insulation Penetrations - seals and thermal barriers Space Shuttle Orbiter RCC Components Wing Nose Cap Leading and Seals Edge Panel Chin Panel and Seals Forward ET. Attach Point Arrowhead RCC Plates HRSI Tile System Orbiter TPS: Operational Issues Flight Processing On-Orbit Inspections Protruding Gap Filler FRSI and Filler Gap Bar Fillers and Thermal Barriers EVA. FI Blankets During STS-114. ReWaterproofing RSI. Tiles 29. Launch Vehicles Need TPS. Aerodynamic Heating Heating Plume-induced Heating Space Shuttle Space Launch System Retired 2011 1st Launch 2021. 30. Current TPS. Multi-Purpose Crew Vehicle SpaceX Dragon Capsule Orion Heat Shield Note: SpaceX.

10 Makes their own PICA. Avcoat (Apollo) but in Block Form Phenolic Impregnated Carbon Ablator (PICA). Mars 2020. 31. TPS in the Future Increase Robustness Reduce Weight Graded Ablator 3-D Woven Carbon Fibers High Density to Lower Density Infiltrated with Resin Improve Manufacturing/ Reduce Costs Conformable Ablator Infiltrated Felts Let's 3D Print it! 32. Questions?? 33.