The ADVENT of a Better Jet Engine?
The Adaptive Versatile Engine Technology (ADVENT) program aims “to develop and demonstrate inlet, engine, exhaust nozzle, and integrated thermal management technologies that enable optimized propulsion system performance over a broad range of altitude and flight velocity.” That sounds boring, but what if we put it like this:
ADVENT is a 5-year project that aims to produce a revolution in jet engine design. Imagine the jet equivalent of a car engine that could give you Formula One performance or sub-compact mileage as required. ADVENT-equipped aircraft would have extra-long range, but be able to switch quickly to high-speed power maneuvers and still be comparatively efficient. The new engine design will use adaptive fan blades and engine cores to generate high thrust when needed, and optimize fuel efficiency when cruising or loitering, in order to combine the best characteristics of high-performance and fuel-efficient jet engines.
That certainly sounds much more exciting. Now, ADVENT also sounds very real – because the program is under way, with over $600 million in contracts to 4 different vendors… and 2 big losers.
ADVENT, HEETE, and VAATE
Project ADVENT is a actually the flagship effort under the Versatile, Affordable Advanced Turbine Engines Program, or VAATE. Managed by the Propulsion Directorate, VAATE’s goal is to increase turbine engine affordability tenfold while improving performance.
The VAATE program, structured around 4 focus areas, emphasizes specific themes important to achieving the affordability goal. The Durability Focus Area aims to develop, design, and test protocols to prevent component failure, increase life, enhance reparability, and perhaps improve performance. The Versatile Core Focus Area, will develop technologies for a multi-use, 4000-hour, maintenance-friendly engine core (compressor, combustor, and turbine). The third area, the Intelligent Engine Focus Area, will develop and integrate technologies that provide durable, adaptive, damage-tolerant engine health and life management features. Finally, engine-airframe integration technologies are key in attaining the significant cost and weight reductions required in order to achieve the VAATE tenfold goal.
The smaller Highly Efficient Embedded Turbine Engine (HEETE) program is a parallel and related effort, aiming to prove that a “quantum leap” in high-pressure compressor systems is possible. If that 3-year project proves successful, the AFRL would seek to integrate HEETE’s more advanced compressor systems into VAATE, incorporating these advances into the new engine cores developed under the ADVENT project.
The DefenseLNIK contract announcements states that:
“The ADVENT program will demonstrate integration technologies to Technology Readiness Level (TRL) 4-5 and engine technologies to TRL-6 in a large thrust class, with emphasis on multi-design point demonstration of significant advancements in thrust, fuel efficiency, development cost, production cost and maintenance cost characteristics over baseline engines.”
Technology Readiness Level 4-5 means lab tests where basic technological components are integrated to establish that the pieces will work together (TRL 4), with reasonably realistic supporting elements so that the technology can be tested in a simulated environment (TRL 5). Examples include ‘high fidelity’ laboratory integration of components. TRL 6 is a major step up, and involves a working prototype that can be tested in a relevant environment.
As for “significant advancements in… development cost, production cost and maintenance cost characteristics,” that will probably happen, but not in the way the USAF was thinking. Barring significant successes on ADVENT’s other fronts, variable engines are likely to be more complex to develop, may see higher production costs due to material requirements for higher temperature tolerances, and may also involve higher maintenance costs if the result is more moving parts. On the flip side, greater engine standardization might be possible, which may provide some maintenance savings.
VAATE seeks to transcend all of these limitations, but research programs rarely hit all of their goals. Even if all of the negative predictions above held true, however, an ADVENT-type engine would definitely save money on operating costs, while offering higher performance. This would still be worth the extra purchase investment for many airlines, and for some power generation applications as well. Those are considerable benefits all by themselves, and the Air Force’s need for extra power in life-or-death situations would make them the most obvious customer of all.
Contracts & Key Events
Unless otherwise specified, the Air Force Research Laboratory at Wright-Patterson Air Force Base, OH issued the contracts.
Oct 18/09: Rolls-Royce North American Technologies, Inc. announces its selection to proceed with Phase II of ADVENT development. Next steps will include the integration of a variety of advanced technologies, component testing and development of a technology demonstrator core and engine. See also: Britain’s Times.
Oct 1/07: The AFRL rejected bids by United Technologies subsidiary Pratt & Whitney and by Honeywell to win the so-called Highly Efficient Embedded Turbine Engine (HEETE) contracts, one month after P&W was the sole losing bidder for the AFRL’s Adaptive Versatile Engine Technology (ADVENT) program. Flight International explains the implications:
“P&W’s loss of both ADVENT and HEETE means it must devote internal research and development funds to keep pace with its rivals after production of its latest generation fighter engine – the Lockheed Martin F-35 Joint Strike Fighter’s F135 – runs its course… The HEETE project is necessary because the commercial technology stops short of the military’s requirements for next-generation compressor systems, with the contract aiming to prove that a “quantum leap” in high-pressure compressor systems is possible. If the three-year project proves successful, the AFRL would seek to integrate HEETE’s more advanced compressor systems into the new engine cores developed under the ADVENT project.”
Sept 27/07: Northrop Grumman Integrated Systems Sector of El Segundo, CA received an indefinite delivery/indefinite quantity contract for $40 million. The objective of the ADVENT program is to develop and demonstrate inlet, engine, exhaust nozzle, and integrated thermal management technologies that enable optimized propulsion system performance over a broad range of altitude and flight velocity.
The ADVENT program will demonstrate integration technologies to TRL 4-5 [components tested] and engine technologies to TRL-6 [prototype] in a large thrust class (25,000 lbs.) with emphasis on multi-design point demonstration of significant advancements in thrust, fuel efficiency, development cost, production cost and maintenance cost characteristics over baseline engines. At this time $1,000 has been obligated (FA8650-07-D-2800).
Sept 25/07: The US Air Force Research Laboratory has awarded a total of $35.6 million in cost-share contracts to Rolls Royce-North American Technologies Inc., and General Electric Co. to begin developing a game-changing class of engines, known as Highly Efficient Embedded Turbine Engines (HEETE). Rolls Royce will be receiving $19.6 million in its portion of the contracts while General Electric will receive $16 million. Rolls Royce and GE will conduct high-pressure and high-temperature rig tests on the compression systems that are critical to the HEETE concept. Development work will be conducted at Rolls Royce’s Liberty Works facilities in Indianapolis, IN; and at General Electric’s Evendale, OH, facility. Rolls Royce release.
HEETE is a technology development program that pursues high temperature, high pressure ratio compressor technologies and their related thermal management features. While HEETE is currently focused on an advanced compressor demonstration, the goal is to define the next generation engine architecture for subsonic missions. This also involves active flow control inlets and exhausts, with a focus on 20,000-35,000 pound thrust class. There were also losers. Flight International adds:
“The US Air Force Research Laboratory (AFRL) announced on 25 September awarding contracts to General Electric and Rolls-Royce… However, the AFRL rejected bids by Pratt and Honeywell to win the so-called Highly Efficient Embedded Turbine Engine (HEETE) contracts.”
Sept 21/07:Lockheed Martin Aeronautics Company-Fort Worth of Fort Worth, TX received an indefinite-delivery/ indefinite-quantity, cost-reimbursement contract for $40 million (maximum) for the ADVENT program. The emphasis will be on multi-design point demonstration of significant advancements in thrust, fuel efficiency, development cost, production cost and maintenance cost characteristics over baseline engines. It covers demonstration of integration technologies to TRL 4-5 and engine technologies to TRL-6 in a large thrust class (25,000 lbs.). At this time $1,000 has been obligated (FA8650-07-D2798).
Aug 27/07: General Electric Aircraft Engines in Cincinnati, OH received a cost-sharing ADVENT contract for $231.2 million. At this time, $129,140 has been obligated. Solicitations began in March 2007, negotiations were completed in August 2007, and work will be complete in September 2012 (FA8650-07-C-2802).
The AFRL explained to DID that this award was originally announced at the same time as the Rolls Royce award, on Aug 15/07. In reality, however, it hadn’t been finalized yet. Hence the repeat announcement. We’ve revised the date accordingly.
Aug 15/07: Rolls-Royce Corp. in Indianapolis, IN received a cost-sharing ADVENT contract for $296.3 million. At this time, $98,770 has been obligated. Solicitations began in March 2007, negotiations were completed in August 2007, and work will be complete in September 2012 (FA8650-07-C-2803). Rolls Royce release.
Additional Readings & Sources
- Flight International (May 1/07) – Military engines: Power Surge
- US Air Force (March 27/07) – Air Force plans to develop revolutionary engine
- Aviation Week Ares (March 27/07) – Stop and go
- Air Force Research Laboratory, Horizons Magazine (December 2001) – Future Aircraft Jet Engines Will Think for Themselves