News 1998 Army Science and Technology Master Plan

2. Aerospace Propulsion and Power

Aerospace propulsion and power focuses on technologies that will result in aircraft and missile propulsion systems and components, including prime power transmission, that are more compact, lighter weight, higher horsepower, more fuel efficient, and lower cost than those currently available. Advances in this area are needed to support Army objectives for improved rotorcraft and transport performance, and for other services, attack and fighter aircraft and unmanned air vehicles (UAVs).

Technology subareas include rotorcraft propulsion (encompassing small gas turbine engines and rotorcraft drive systems) and fuels and lubricants. Table E–5 and the following paragraphs summarize key capabilities and trends in each technology subarea.

Table E–5.  International Research Capabilities—Aerospace Propulsion and Power


United Kingdom




Asia/Pacific Rim


Other Countries

Small Turbine Engines 2s.gif (968 bytes) 1s.gif (931 bytes) High–temperature structures

Rotorcraft propulsion

2s.gif (968 bytes) High–temperature gas turbines; rotorcraft propulsion 5s.gif (958 bytes) Ceramics   Russia

3s.gif (977 bytes) Wind tunnel test facilities

Israel, Canada

5s.gif (958 bytes) Small gas turbines

Rotorcraft Power Transfer Systems 2s.gif (968 bytes) High–performance transmission 1s.gif (931 bytes) Bearingless rotor hub 1s.gif (931 bytes) Bearingless rotor hub; composite & high–strength allow shafting        
Fuels & Lubricants   2s.gif (968 bytes) High–temperature lubricants 2s.gif (968 bytes) High–temperature lubricants        
Note: See Annex E, Section A.6 for explanation of key numerals.

a. Small Turbine Engines

The Army, other services, NASA, DARPA, and industry are working together to reduce specific fuel consumption by 40 percent and increase the power–to–weight ratio by 20 percent in engines by FY03. This will significantly improve Army rotorcraft range and payload characteristics. This technology will also be applicable to ground vehicles. Technical challenges in gas turbine engine technology include:

High–temperature, lightweight materials, including metal matrix composites (MMCs) and ceramic matrix composites (CMCs)
Efficient, highly loaded, wide–range compressors and turbines
High–temperature, high–speed, high–pressure engine mechanical parts (e.g., bearings, seals, gears)
Computationally efficient, experimentally validated advanced design codes.

The importance of gas turbine propulsion in civilian aircraft markets has led to the development of worldwide capabilities, with over 40 producers in 11 countries listed as suppliers in recent global surveys. Many other countries have technologies for repair and overhaul. Market figures indicate that the United States has continued to capture a growing share in a declining market, largely through exports. A growing number of companies look to international joint ventures as a strategy for remaining competitive in this market. International cooperative R&D in gas turbine technology may, in addition to providing access to state–of–the–art technology, provide access to an increasingly competitive international market.

France, Germany, and the U.K. are at or nearly at a par with the U.S. in many aspects. Key areas of capability with leveraging potential include materials and coatings, and related structures and aerodynamic design and modeling. Russia, Canada, Israel, and Japan have substantial infrastructures and niches of excellence (e.g., Japan, ceramics; Canada, small gas turboprops).

One area offering special opportunities relates to the French expertise in ceramic materials for gas turbine engines. Ceramic material technologies can provide significant enhancements over currently fielded systems. In particular, they offer lightweight, fuel efficient engines with greatly increased power–to–weight ratios, and are capable of operation at high temperatures. While the U.S., Germany, and Japan also are world leaders in ceramic technologies, France is a recognized leader in ceramic/carbon composites, which are most applicable to gas turbine engines. Existing agreements with France provide a potential vehicle for establishing a cooperative agreement in this area.

b. Rotorcraft Power Transfer Systems

Drive train and power transfer research is required to lower weight, volume, noise, and increase durability. Technical challenges in rotorcraft drive technology include:

Lightweight, high–strength, tribologically robust gear materials
Accurate dynamic noise and life prediction codes
Minimum lubricant weight designs
Efficient, lightweight, high–power density electric drive components.

The U.K. has strong capabilities in high–performance power transmission technologies. France has expertise in bearingless rotor hubs, as does Germany. Germany also has noteworthy capabilities in composite materials and high–strength alloy shafting.

c. Fuels and Lubricants

The Army’s main interest in the fuels and lubricants subarea is the development and validation of new analytical technologies. Of particular interest are techniques for rapid assessment of petroleum quality using spectroscopic and chromatographic methods. New analytical methods will enable a significant reduction in operational requirements for petroleum testing in the field. This includes less manpower, reduced test time, and less test hardware. Technical challenges relate to compressing testing time, developing improved detection systems, correlating testing results, and developing computer–based expert systems.

In this subarea, France and Germany are the only countries noted as having special capabilities, both in the area of high–temperature lubricants.

AMC POC: Dr. Rodney Smith
Army Materiel Command
5001 Eisenhower Blvd.
Alexandria, VA 22333–0001
e–mail: [email protected]

IPOC: Mr. Dennis Earley
St. Louis, MO 63120–1798
e–mail: [email protected]

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