航空发动机

Pratt Unveils Sixth-Generation Fighter Engine, F135 Upgrade Options

http://aviationweek.com/defense/ ... 135-upgrade-options

09 Apr 2015

Pratt & Whitney has revealed details of a mid-to-long-term development road map designed to protect both its position as sole engine provider on the Lockheed Martin F-35 Joint Strike Fighter (JSF) as well as its prospects for powering sixth-generation combat aircraft.

The ambitious plan builds on upgrades already under development for the F135 engine that powers the F-35, as well as a raft of advanced technologies currently being evaluated or studied for the next generation of adaptive, or variable-cycle engines. The strategic effort is also focused on sustaining Pratt as a major fighter-engine developer beyond the F135, the system development and demonstration (SDD) phase for which ends in 2016.

While Pratt makes it clear that there is currently no firm requirement for an upgraded F135, the company is working with the U.S. Navy on a fuel-burn improvement program for the engine, which combined with other turbine cooling technologies recently tested on the XTE68/LF1 demonstrator engine could be packaged as the first block of a two-step enhancement. “The Navy is working with us to develop technology for an engine test next year that would demonstrate a 5% fuel-burn reduction in the F-35,” says Pratt & Whitney’s Advanced Programs and Technology Director Jimmy Kenyon. This would be grouped potentially with blade-cooling technology demonstrated in late 2013 on XTE68/LF1, which Kenyon describes as “a fantastically successful test. It was the highest-ever turbine temperature in a production-based engine.”

The block one improvement will offer between a 7% and 10% improvement in thrust, as well as between 5% and 7% better mission fuel burn, and could be available around 2018. “So far, no one has decided they need the capability but we are making sure we are providing the options,” says Pratt & Whitney Military Engines President Bennett Croswell.

Although higher thrust and better fuel burn have obvious payload, range and mission advantages, Pratt expects the main benefit to come from trading the performance for lower operating temperatures and longer time on wing. “We are planning a life-extension for the F135, like we did on the [F100] -229 with an engine enhancement package where you had a 50% improvement in life. So we have set a goal to reduce sustainment costs for the F135 by a factor of 30%. A big piece of that will be increasing the life, which means reducing the number of depot overhauls you do over the life of the engine,” says Croswell. “The real focus for the Joint Program Office and Navy is on reducing life-cycle cost,” adds Kenyon.

For a longer-term block two upgrade path, Pratt is studying the possibility of configuring the F135 with elements of a technology suite in development for the U.S. Air Force Research Laboratory’s (AFRL) Adaptive Engine Transition Program (AETP). Tipped for possible start-up funding later this year, AETP is primarily designed to prepare the ground for an adaptive, 45,000-lb.-thrust-class combat engine for sixth-generation fighter aircraft. However, the stated provisions for the program also make it a possible future reengining candidate for the F-35, the prospect of which is also driving advanced engine development work at General Electric.

Both Pratt and GE are currently engaged in AFRL’s Adaptive Engine Technology Development (AETD) program, a progenitor to AETP aimed at testing technology for a new generation of “three-stream” engines that can be reconfigured in flight. The adaptive concept is based on the principle of adding a third airflow stream outside of both the standard bypass duct and core. The extra airflow can be adapted to provide either additional mass flow for increased propulsive efficiency and lower fuel burn in higher bypass mode for cruise or, alternatively, for high-speed flight it can provide extra cooling capacity for the hot section of the engine, as well as for the fuel that provides a heat sink for aircraft systems.

AETD is set to end with demonstrations in 2016, by which time the follow-on program is scheduled to be underway. The four-year effort will mature adaptive engine technologies and reduce risk in readiness for a competitive engineering and manufacturing development (EMD) program. Pratt will conduct a preliminary design review of its AETD engine this month and has begun assembly of parts for a new high pressure-ratio core that will be tested in 2016. The manufacturer, which also has been rig-testing a three-stream adaptive fan, will attach the fan to an F135 for full engine tests at the company’s West Palm Beach, Florida, facility next year. The engine will also be fitted with a three-stream-compatible augmentor and exhaust system.

“We are looking at how we can take technology from that engine and use it within an F135-based architecture. We could potentially get a lot of that capability improvement for a lot less cost because we are already starting with a known engine and looking at an upgrade,” says Kenyon. “So we are working on different trades about how much the technology would bring in, how much that would cost and what kind of capability it would provide us as we go forward. The great thing about AETP is you are going to build and test and really wring out this technology, so by the time we get to the end of it that technology will be pretty mature.” As a result, Kenyon adds that “getting it into an F-35 would really not be as difficult or expensive as it would be to now take it forward to a brand-new engine.”Block two would therefore take elements of the advanced engine—in particular a new compressor and turbine— and feed it into the F135 for as much as a 15% thrust increase and a 20% reduction in fuel burn. “The compressor has more stages. It fits and is compatible with the current engine,” says Croswell, who adds the upgrade could be available in the 2022 timeframe if development of this, and the associated block one improvement, is approved soon. Although there is “still flow capacity in the inlet that we are not using,” Croswell acknowledges that the tightly packed F-35 fuselage does not allow for much leeway when it comes to providing space for a third stream. “Lockheed would like us not to tear up the airplane a lot, so I don’t know if we can integrate a third stream, but we will do those trades. We have defined what we could offer, and it is not part of the block upgrade plan as yet.”

Pratt is also working with the Navy on the Variable Cycle Advanced Technology (VCAT) program, which is designed to identify and mature adaptive-cycle turbine propulsion technology for future carrier-based tactical and intelligence, surveillance and reconnaissance systems. The VCAT program, which leverages the AFRL variable-cycle work, is a partnership effort between the Office of Naval Research and ONR and the Navy’s Energy Task Force, and is exploring additional unspecified methods of using the turbine stages to adapt the cycle. VCAT technology “is not part of the block two strategy right now, but it could be,” says Croswell.

────────────────────────────────────────────────────────────────────────
1.技术上block1升级可以在2018,5~7%增推和7~10%燃油效率

2.新技术的引入没有很困难和贵

3.顺利话2022可能可以有block2升级,增推15%和20%燃油效率

4.但空间限制可能不会有第三道流设计。麻烦点是可以升级有第三道流,但不在计画中







我去！没用ATED的三道流,只更换压缩机和涡扇,就達到增推、省油、延长发动机寿命，还降低维护费用

这可能嘛？



Pratt Unveils Sixth-Generation Fighter Engine, F135 Upgrade Options

http://aviationweek.com/defense/ ... 135-upgrade-options

09 Apr 2015

Pratt & Whitney has revealed details of a mid-to-long-term development road map designed to protect both its position as sole engine provider on the Lockheed Martin F-35 Joint Strike Fighter (JSF) as well as its prospects for powering sixth-generation combat aircraft.

The ambitious plan builds on upgrades already under development for the F135 engine that powers the F-35, as well as a raft of advanced technologies currently being evaluated or studied for the next generation of adaptive, or variable-cycle engines. The strategic effort is also focused on sustaining Pratt as a major fighter-engine developer beyond the F135, the system development and demonstration (SDD) phase for which ends in 2016.

While Pratt makes it clear that there is currently no firm requirement for an upgraded F135, the company is working with the U.S. Navy on a fuel-burn improvement program for the engine, which combined with other turbine cooling technologies recently tested on the XTE68/LF1 demonstrator engine could be packaged as the first block of a two-step enhancement. “The Navy is working with us to develop technology for an engine test next year that would demonstrate a 5% fuel-burn reduction in the F-35,” says Pratt & Whitney’s Advanced Programs and Technology Director Jimmy Kenyon. This would be grouped potentially with blade-cooling technology demonstrated in late 2013 on XTE68/LF1, which Kenyon describes as “a fantastically successful test. It was the highest-ever turbine temperature in a production-based engine.”

The block one improvement will offer between a 7% and 10% improvement in thrust, as well as between 5% and 7% better mission fuel burn, and could be available around 2018. “So far, no one has decided they need the capability but we are making sure we are providing the options,” says Pratt & Whitney Military Engines President Bennett Croswell.

Although higher thrust and better fuel burn have obvious payload, range and mission advantages, Pratt expects the main benefit to come from trading the performance for lower operating temperatures and longer time on wing. “We are planning a life-extension for the F135, like we did on the [F100] -229 with an engine enhancement package where you had a 50% improvement in life. So we have set a goal to reduce sustainment costs for the F135 by a factor of 30%. A big piece of that will be increasing the life, which means reducing the number of depot overhauls you do over the life of the engine,” says Croswell. “The real focus for the Joint Program Office and Navy is on reducing life-cycle cost,” adds Kenyon.

For a longer-term block two upgrade path, Pratt is studying the possibility of configuring the F135 with elements of a technology suite in development for the U.S. Air Force Research Laboratory’s (AFRL) Adaptive Engine Transition Program (AETP). Tipped for possible start-up funding later this year, AETP is primarily designed to prepare the ground for an adaptive, 45,000-lb.-thrust-class combat engine for sixth-generation fighter aircraft. However, the stated provisions for the program also make it a possible future reengining candidate for the F-35, the prospect of which is also driving advanced engine development work at General Electric.

Both Pratt and GE are currently engaged in AFRL’s Adaptive Engine Technology Development (AETD) program, a progenitor to AETP aimed at testing technology for a new generation of “three-stream” engines that can be reconfigured in flight. The adaptive concept is based on the principle of adding a third airflow stream outside of both the standard bypass duct and core. The extra airflow can be adapted to provide either additional mass flow for increased propulsive efficiency and lower fuel burn in higher bypass mode for cruise or, alternatively, for high-speed flight it can provide extra cooling capacity for the hot section of the engine, as well as for the fuel that provides a heat sink for aircraft systems.

AETD is set to end with demonstrations in 2016, by which time the follow-on program is scheduled to be underway. The four-year effort will mature adaptive engine technologies and reduce risk in readiness for a competitive engineering and manufacturing development (EMD) program. Pratt will conduct a preliminary design review of its AETD engine this month and has begun assembly of parts for a new high pressure-ratio core that will be tested in 2016. The manufacturer, which also has been rig-testing a three-stream adaptive fan, will attach the fan to an F135 for full engine tests at the company’s West Palm Beach, Florida, facility next year. The engine will also be fitted with a three-stream-compatible augmentor and exhaust system.

“We are looking at how we can take technology from that engine and use it within an F135-based architecture. We could potentially get a lot of that capability improvement for a lot less cost because we are already starting with a known engine and looking at an upgrade,” says Kenyon. “So we are working on different trades about how much the technology would bring in, how much that would cost and what kind of capability it would provide us as we go forward. The great thing about AETP is you are going to build and test and really wring out this technology, so by the time we get to the end of it that technology will be pretty mature.” As a result, Kenyon adds that “getting it into an F-35 would really not be as difficult or expensive as it would be to now take it forward to a brand-new engine.”Block two would therefore take elements of the advanced engine—in particular a new compressor and turbine— and feed it into the F135 for as much as a 15% thrust increase and a 20% reduction in fuel burn. “The compressor has more stages. It fits and is compatible with the current engine,” says Croswell, who adds the upgrade could be available in the 2022 timeframe if development of this, and the associated block one improvement, is approved soon. Although there is “still flow capacity in the inlet that we are not using,” Croswell acknowledges that the tightly packed F-35 fuselage does not allow for much leeway when it comes to providing space for a third stream. “Lockheed would like us not to tear up the airplane a lot, so I don’t know if we can integrate a third stream, but we will do those trades. We have defined what we could offer, and it is not part of the block upgrade plan as yet.”

Pratt is also working with the Navy on the Variable Cycle Advanced Technology (VCAT) program, which is designed to identify and mature adaptive-cycle turbine propulsion technology for future carrier-based tactical and intelligence, surveillance and reconnaissance systems. The VCAT program, which leverages the AFRL variable-cycle work, is a partnership effort between the Office of Naval Research and ONR and the Navy’s Energy Task Force, and is exploring additional unspecified methods of using the turbine stages to adapt the cycle. VCAT technology “is not part of the block two strategy right now, but it could be,” says Croswell.

────────────────────────────────────────────────────────────────────────
1.技术上block1升级可以在2018,5~7%增推和7~10%燃油效率

2.新技术的引入没有很困难和贵

3.顺利话2022可能可以有block2升级,增推15%和20%燃油效率

4.但空间限制可能不会有第三道流设计。麻烦点是可以升级有第三道流,但不在计画中







我去！没用ATED的三道流,只更换压缩机和涡扇,就達到增推、省油、延长发动机寿命，还降低维护费用

这可能嘛？