The Air Force B-70 Valkyrie - An Example of Next Generation Aerospace Vehicles

1961 ◽  
Author(s):  
Latham Pollock
Keyword(s):  
Air Force ◽  
Next Generation ◽  
Aerospace Vehicles

Polyimide Foams for Aerospace Vehicles

2000 ◽  
Vol 12 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Erik S Weiser ◽  
Theodore F Johnson ◽  
Terry L St Clair ◽  
Yoshiaki Echigo ◽  
Hisayasu Kaneshiro ◽  
...  
Keyword(s):  
Next Generation ◽  
Cyclic Testing ◽  
Aerospace Vehicles ◽  
Limiting Oxygen Index ◽  
Excellent Thermal Stability ◽  
Foaming Agents ◽  
Thermal Forming ◽  
Reusable Launch Vehicle ◽  
Wide Range ◽  
Langley Research Center

Due to a demand by the aerospace industry, NASA has begun developing the next generation of polyimide foams which could be utilized to reduce vehicle weight for the X-33 and Reusable Launch Vehicle (RLV) programmes. The activity at NASA Langley Research Center focuses on developing polyimide foam and foam structures which are made using monomeric solutions or salt solutions formed from the reaction of a dianhydride and diamine dissolved in a mixture of foaming agents and alkyl alcohols. This process can produce polyimide foams with varying properties from a large number of monomers and monomer blends. The specific densities of these foams can range from 0.008 g cc−1 to 0.32 g cc−1. Polyimide foams at densities of 0.032 g cc−1 and 0.08 g cc−1 were tested for a wide range of physical properties. The foams demonstrated excellent thermal stability at 321°C, a good thermal conductivity at 25°C of 0.03 W m−1 K−1, compressive strengths as high as 0.84 MPa at 10% deflection and a limiting oxygen index of 51%. Thermomechanical cyclic testing was also performed on these materials for 50 cycles at temperatures from −253°C to 204°C. The foams survived the cyclic testing without debonding or cracking. Thermal forming of the 0.032 g cc−1 foam was performed and a minimum radius curvature of 0.0711 m was achieved. The foams exhibited excellent properties overall and are shown to be viable for use as cryogenic insulation on the next generation RLV.

scholarly journals Next Generation 2 MW Turboshaft and Turboprop Engines

1993 ◽  
Author(s):  
Robert L. Vogt ◽  
Arun Sehra
Keyword(s):  
Air Force ◽  
Low Cost ◽  
Advanced Technology ◽  
Next Generation ◽  
Us Army ◽  
Us Air Force ◽  
Us Navy ◽  
Near Term ◽  
Turboshaft Engine ◽  
The U.S

Textron Lycoming of Stratford, Connecticut is incorporating the latest in advanced technology into turboshaft and turboprop engines for near term commercial service. The level of cold section technology being incorporated is the already demonstrated next generation of axi-centrifugal compressor beyond that which was developed for the U.S. Army T800, 0.9 MW turboshaft engine in the late 1980s. The compressor evolution is given special emphasis. The hot section technology is a robust, simplified, low cost, commercial endurance derate of the tri-service; US Army, US Navy, US Air Force and Textron Lycoming joint core engine [1] now on test. The new 2 MW commercial engine has substantially reduced fuel consumption, is lighter, and is smaller than today’s best engines. Engineering development is now underway and certification is slated to be completed in 1996.

An Overview of Potential Titanium Aluminide Composites in Aerospace Applications

1992 ◽  
Vol 273 ◽  
Author(s):  
James M. Larsen ◽  
William C. Revelos ◽  
Mary L. Gambone
Keyword(s):  
High Temperature ◽  
Air Force ◽  
Titanium Aluminide ◽  
High Performance ◽  
Matrix Composites ◽  
Enabling Technology ◽  
Aerospace Vehicles ◽  
Aerospace Applications ◽  
Monotonic Properties ◽  
Temperature Time

ABSTRACTHigh-temperature, light-weight materials represent enabling technology in the continued evolution of high-performance aerospace vehicles and propulsion systems being pursued by the U.S. Air Force. In this regard, titanium aluminide matrix composites appear to offer unique advantages in terms of a variety of weightspecific properties at high temperatures. However, a key requirement for eventual structural use of these materials is a balance of mechanical properties that can be suitably exploited by aircraft and engine designers without compromising reliability. An overview of the current capability of titanium aluminide composites is presented, with an effort to assess the balance of properties offered by this class of materials. Emphasis is given to life-limiting cyclic and monotonic properties and the roles of high-temperature, time-dependent deformation and environmental effects. An attempt is made to assess the limitations of currently available titanium aluminide composites with respect to application needs and to suggest avenues for improvements in key properties.

Hearing Conservation in the U.S. Air Force

2004 ◽  
Vol 10 (1) ◽  
pp. 25-27
Author(s):  
Jonathan Thomas ◽  
Gabriel Almario
Keyword(s):  
Air Force ◽  
Hearing Conservation ◽  
The U.S
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