Pratt & Whitney XA101
The Pratt & Whitney XA101 is a three-stream adaptive cycle engine demonstrator being developed by Pratt & Whitney for the Lockheed Martin F-35 Lightning and for the U.S. Air Force's sixth generation fighter program.
XA101 | |
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Type | Adaptive cycle engine |
National origin | United States |
Manufacturer | Pratt & Whitney |
Major applications | F-35 Lightning II (planned) |
The three-stream adaptive cycle design can direct air to the bypass third stream for increased fuel efficiency and cooling or to the core and fan streams for additional thrust and performance. The 45,000 lbf (200 kN) thrust class engine is expected to be significantly more powerful and efficient than existing low-bypass turbofans.
Development
The U.S. Air Force and U.S. Navy began pursuing adaptive cycle engine in 2007 with the Adaptive Versatile Engine Technology (ADVENT) program, a part of the larger Versatile Affordable Advanced Turbine Engine (VAATE) program. While not involved with ADVENT, Pratt & Whitney was selected alongside General Electric for the Adaptive Engine Technology Demonstrator (AETD) program that followed in 2012; this program continued to mature the technology, with tests performed using demonstrator engines. The next step, the Adaptive Engine Transition Program (AETP), was launched in 2016 to develop and test adaptive engines for sixth generation fighter propulsion as well as potential re-engining of the F-35 from the existing F135 turbofan engine. The demonstrators were assigned the designation XA100 for General Electric's design and XA101 for Pratt & Whitney's. The AETP goal is to demonstrate 25% improved fuel efficiency, 10% additional thrust, and significantly better thermal management.[1] In 2017, Pratt & Whitney successfully tested an adaptive three-stream fan with an F135 core, and considered the XA101 to be "Growth Option 2.0" in its long-term development plan for the F135.[2][3][4] Further contract awards and modifications from Air Force Life Cycle Management Center (AFLCMC) in 2018 increased the focus on re-engining of the F-35; there has also been investigations on applying the technology in upgrades for F-15, F-16, and F-22 propulsion systems.[5] In June 2018, Pratt & Whitney changed its development plan for the F135, and instead offered an adaptive three-stream fan as Growth Option 2.0 that's separate from the XA101, which would instead have a new engine core.[6][7]
Design
The XA101 is a three-stream adaptive cycle engine that can adjust the bypass ratio and fan pressure to increase fuel efficiency or thrust, depending on the scenario. It does this by employing a third bypass stream where the engine can direct air to in order to increase fuel economy and act as a heat sink for cooling; in particular, this would enable greater use of the high speed, low altitude part of the F-35 envelope. The increased cooling and power generation also enables the potential employment of directed energy weapons in the future. When additional thrust is needed, the air from the third stream can be directed into the core and fan streams for increased performance.[8]
Applications
- Lockheed Martin F-35 (planned)
Specifications (XA101)
Data from Flight Global,[5]
General characteristics
- Type: Three-stream adaptive cycle engine
- Length:
- Diameter:
- Dry weight:
Components
- Compressor:
Performance
- Maximum thrust:
- 45,000 lbf (200 kN) class (with afterburner)
- Power-to-weight ratio:
See also
Related development
Comparable engines
Related lists
References
- Mehta, Aaron (1 July 2016). "US Air Force Funds Next Advanced Engine Stage". DefenseNews. Retrieved 11 January 2020.
- Kjelgaard, Christ (15 June 2017). "P&W Outlines Three-step F135 Development Pathway". Aviation International News. Retrieved 11 January 2020.
- Insinna, Valerie (18 September 2017). "Eyeing the future fighter, Pratt & Whitney hits milestone with new adaptive engine". DefenseNews. Retrieved 11 January 2020.
- Norris, Guy (29 January 2015). "GE Details Sixth-Generation Adaptive Fighter Engine Plan". Aviation Week. Retrieved 11 January 2020.
- Trimble, Steven (9 July 2018). "USAF starts work on defining adaptive engine for future fighter". Flight Global. Retrieved 11 January 2020.
- Kjelgaard, Chris (13 June 2018). "P&W Outlines New Plan for F-35 Engine Upgrades". Aviation International News. Retrieved 11 January 2020.
- Norris, Guy; Anselmo, Joe (21 July 2018). "F-35 Engine Upgrade Would Enable Directed Energy Weapons". Aviation Week. Retrieved 11 January 2020.
- Mathews, Jim (26 June 2017). "Engines of Innovation". Air Force Magazine. Retrieved 11 January 2020.