Adaptive cycle engine enters final phase of development

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The US Air Force has awarded two five-year development contracts to GE Aviation and Pratt & Whitney worth up to $1 billion each to continue development of a next-generation military jet engine and prepare for an anticipated competition in the early 2020s for the chance to power a new combat aircraft and possibly re-engine the Lockheed Martin F-35.

The awards of the Adaptive Engine Transition Programme (AETP) contracts to GE and P&W on 30 June extends a nearly 10-year effort to introduce a fuel-saving cruise mode into an engine intended for a supersonic fighter. Both contractors will develop and test multiple new centreline engines sized at a 45,000lb-thrust level.

“We believe GE is best positioned to integrate the adaptive suite of technologies into existing and next-generation combat aircraft,” says Dan McCormick, general manager of GE Aviation’s Advanced Combat Engine programmes.

P&W was not immediately available for comment.

The USAF is developing concepts for replacing the Lockheed F-22 after 2030, which includes updating existing designs with new technology. Re-engining the F-35 with an adaptive cycle, 45,000lb-thrust engine is also under study.

An adaptive-cycle engine is intended to address a design limitation in modern powerplants. An engine optimised for subsonic speed is more fuel-efficient, but cannot easily exceed the speed of sound. A supersonic engine, however, can accelerate over Mach 1.0 but is limited in range because it guzzles fuel.

The AETP programme continues development of a technology that could make supersonic engines 25% more fuel-efficient, thus extending the range of a fighter by as much as 30%, according to GE.

There are two kinds of airflow in modern engines. One airflow enters the engine core, mixes with fuel, combusts and generates energy to power the gas turbine machinery and create thrust. Another portion of the airflow enters the inlet and then bypasses the core, generating thrust without the need to consume any fuel directly. An adaptive cycle engine proposes to add a secondary stream of bypass airflow in cruise speed conditions. This secondary duct can be shut off when it’s necessary to accelerate rapidly.

The USAF launched the technology development programme in 2007 with adaptive versatile engine technology programme with GE. P&W and GE then participated in the adaptive engine technology demonstration (AETD) programme that began in 2012. AETD is expected to end later this year.


GE adaptive cycle engine

It was developed under the U.S. Department of Defense’s Adaptive Versatile Engine Technology (ADVENT) and Adaptive Engine Technology Development (AETD) programs, the GE ACE is the only engine that combines outstanding fuel burn with increased, fighter-level thrust, enabling military aircraft to go greater distances and engage more targets.

Unlike traditional engines with fixed airflow, the GE ACE is a variable cycle engine that will automatically alternate between a high-thrust mode for maximum power and a high-efficiency mode for optimum fuel savings. And that means a whole new book of operational possibilities for the U.S. Air Force.

GE has released the first photograph of the fan on its adaptive cycle engine – Image

* Ceramic Matrix Composite (CMC) materials enable the GE ACE to achieve the highest core temperature ever recorded.
* GE is using 3D technology to develop complex components one layer at a time and open the creative canvass for engineers.
* the GE ACE can withstand higher temperatures than ever before.

General Electric put out a release about testing for its Adaptive Versatile Engine Technology (ADVENT) project, which achieved the highest combined compressor and turbine temperature operation “in the history of jet engine propulsion.

GE’s unique adaptive cycle, three-stream engine architecture could bring fighters of the future both higher performance and longer range with less fuel burn.

The adaptive cycle engine is building on decades of military and civilian jet engine research. Innovative architecture shifts air flow between the core, the main bypass, and a third stream to achieve thrust, optimal performance, and fuel efficiency.

GE Jet Sets Record; Will F-35 Get New AETD Engine?

on June 18, 2015 at 8:41 AM

F136 Engine GEA canceled F136 engine being tested

General Electric put out a release late yesterday about testing for its Adaptive Versatile Engine Technology (ADVENT) project, which achieved the highest combined compressor and turbine temperature operation “in the history of jet engine propulsion.”

That release included this sentence: “It is now being applied to the next step – an engine that could fit an F-35-like aircraft.”

You could almost hear the pin drop. Years after former Defense Secretary Bob Gatespushed hard to kill the so-called second engine program — GE’s F136 — it looks as if GE may be poised to come back with what could be either a second engine for the F-35, a replacement for Pratt’s F135, or the next-generation power plant.

(GE and the Air Force Research Lab released a video about the new engine’s testing yesterday. Enjoy.)

GE finished tests on a new engine, which included the highest combined compressor and turbine temperature operation “in the history of jet engine propulsion.”

Daniel McCormick, general manager of GE’s advanced combat engine programs, said there had been a Preliminary Design Review that involved the Air Force, NASA and Lockheed Martin. The new engine can adapt for either maximum thrust — to outrun an enemy anti-aircraft missile, for example — or long-range cruise — say, to penetrate deeply and stealthilyinto an enemy air-defense zone.

As more details emerge it will be fascinating to hear how senior Pentagon officials and Air Force leaders view this GE engine: as a technology marvel, the beginnings of the next generation in F-35 power, or as a “second engine.”

Adaptive Cycle Engine: Farther & Faster


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