GE/Allison Team Advancing Military Propulsion Capabilities
LE BOURGET - The GE (USA)* Aircraft Engines/Allison Engines technology team, formed in July 1994, is moving aggressively in the joint development of advanced propulsion technology to meet future United States military aircraft requirements.
In late 1994, the team was selected as the prime contractor to demonstrate Phase II goals of the Integrated High Performance Turbine Engine Technology Initiative (IHPTET), administered by Wright Patterson Air Force Base for the U.S. Department of Defense. The goal of IHPTET is to double current propulsion capabilities by the year 2003.
In addition to IHPTET efforts, the GE/Allison team has received Joint Attack Strike Technology (JAST) awards of more than $12 million for propulsion studies, technology demonstrations, integration studies, component integration, propulsion diagnostic programs, and manufacturing initiatives. JAST is targeting the next-generation strike weapon systems for the U.S. Navy, Air Force, Marines, and allies for the early 21st century.
As part of IHPTET Phase II, the GE/Allison team is focusing on advanced materials, cooling technology, advanced aerodynamics, and variable cycle technology. The Phase II goal is to demonstrate a 60 percent improvement in propulsion capability and significantly higher temperatures over current state-of-the-art engines by 1997.
"The Allison and GE teaming optimizes Allison's considerable materials and cooling technology and GE's expertise in materials and variable cycle technology," said Harvey Maclin, GE's manager of Technology Programs. Phase II goals are being pursued by GE/Allison through two demonstrator engine programs:
ATEGG: In February, Allison was awarded the USAF-funded Advanced Turbine Engine Gas Generator (ATEGG) core technology demonstrator contract. This is in addition to Allison's 1990 ATEGG contract award.
JTDE: The GE/Allison team will utilize the ATEGG in the USAF/Navy Joint Technology Demonstrator Engine (JTDE) program. This program will be conducted under existing contracts awarded to GE.
This year, the design of variable-cycle engine hardware for ATEGG and JTDE demonstrators will be completed, as will demonstration of a variable-cycle core-drive fan stage and an advanced high-pressure-ratio swept fan design.
Early next year, the GE/Allison team will run its ATEGG core again from the 1990 contract award, with a five-stage compressor and a single-stage high-pressure turbine. In late 1996 or early 1997, a reconfigured ATEGG core from the 1995 contract will be demonstrated with variable-cycle technology, a metal matrix composite compressor, and a high-pressure turbine with Allison's Lamilloy cooling technology.
Variable-cycle technology, a focus of GE advanced engine development efforts for more than a decade, enables an engine to operate as a conventional turbojet at supersonic speed, while demonstrating the characteristics of a more fuel-efficient turbofan at subsonic cruise speeds. "Variable-cycle will better utilize the higher temperatures and higher pressure ratios being demonstrated through IHPTET," said Maclin.
In mid-1997, the GE/Allison team expects to begin ground testing of its JTDE engine, which will incorporate variable-cycle technology, a counter-rotating turbine system, and metal matrix composite materials.
Selected technologies from the IHPTET variable-cycle engine are being studied for JAST. The GE/Allison JAST contract provides a mechanism for evaluating variable-cycle technologies in the various JAST missions along with fixed-cycle engine technologies.
"Technologies from IHPTET initiatives, combined with our internally funded research efforts and lean manufacturing initiatives, are leading the GE/Allison team toward the most affordable, low-risk, and yet advanced, propulsion systems for JAST," said Phil Combs, GE's general manager of the JAST program.