Friday, 2 June 2017

Proposed F-35 engine upgrade validates performance promises


Pratt & Whitney has verified that an unfunded upgrade for the 40,000lb-thrust-class F135 engine could increase the thrust of the Lockheed Martin F-35 by 6-10% and reduce fuel consumption by 5-6%, the company announces on 31 May.

The "growth option 1.0" inserts a package of hardware changes into the F135 power section, consisting of the compressor, combustor and turbine, says Matthew Bromberg, president of P&W Military Engines. By limiting changes to the power module, P&W can deliver the upgrade as a drop-in retrofit and in new production engines for the F-35, he adds.

Ushering the new upgrades into service could take several years. Although P&W has validated the basic technologies in a demonstrator F135 engine, the US joint programme office for the F-35 would have to sponsor a full engineering, manufacturing and development (EMD) programme to prepare the improved engine for production.

If launched now, P&W could begin delivering improved power modules by 2020, Bromberg says.

P&W displayed a demonstrator rig installed in a test cell on the company's sprawling complex in the swamps outside of West Palm Beach, Florida. The demonstrator rig - identified as FX701-01 -- served as a testbed for the new technologies.

Growth option 1.0 becomes available as the US Air Force and Navy researchers pursue even more ambitious upgrades for the F-35 propulsion system.

The advanced engine transition programme (AETP) is expected to develop a new core featuring propulsion technology that "adapts" depending on whether the aircraft is accelerating or cruising. To save fuel, the engine in cruise mode opens a third stream of airflow, which bypasses the core to produce thrust most efficiently.

P&W is developing the XA101 adaptive turbofan engine. GE Aviation is working on the XA102 engine. Both designs are being prepared to possibly replace the F135 and power future combat aircraft.

Original post:

Pratt & Whitney F135

 The Pratt & Whitney F135 two-spool afterburning turbofan engine powers all three variants of the Lockheed Martin F-35 Lightning II - Joint Strike Fighter. The F135 propulsion system is the most powerful fighter engine ever developed.

The F135-PW-100 powers the U.S. Air Force F-35A Conventional Take-Off and Landing (CTOL) variant and provides 28,000 pounds of thrust or as much as 43,000 pounds with afterburner.

The more complex (and almost twice as expensive) F135-PW-600 system is used on the Marine Corps F-35B Short Take-Off and Vertical Landing (STOVL) variant. The system is basically an F135 engine coupled to a lift system manufactured by Rolls-Royce (Rolls-Royce LiftSystem). The Rolls-Royce LiftSystem is comprised of a lift fan, a driveshaft, the 3 Bearing Swivel Module (3BSM), and two roll posts. The driveshaft connects the F135 engine to the lift fan and delivers as much as 29,000 shp. The lift fan provides the forward vertical lift. It is a 50-inch, two-stage counter-rotating fan, which is able to deliver more than 20,000 pounds of thrust. The 3BSM is a swiveling jet pipe, which redirects the main engine thrust downward to provide the rear vertical lift. It can rotate 95 degrees in 2.5 seconds and directs 18,000 pounds of thrust. Aircraft roll control is achieved using two roll posts mounted in the wings of the F-35. These roll posts provide 1,950 pounds of thrust each (bypass thrust from F135 engine). In total, the Rolls-Royce LiftSystem provides 41,900 pounds of thrust.

The F135-PW-400 powers the Navy's F-35C Carrier Variant (CV) and provides 28,000 pounds of thrust or as much as 43,000 pounds with afterburner.

Manufacturer: Pratt & Whitney (United Technologies)
Thrust: 28,000 pounds or 43,000 pounds with afterburner
Rolls-Royce LiftSystem:
Lift Fan (STOVL): 20,000 pounds
3BSM (STOVL): 18,000 pounds
Roll posts (STOVL): 2x 1,950 pounds
Overall Pressure Ratio at Maximum Power: 28
Thrust-to-Weight Ratio: Unknown
Compressor: Two spool, axial flow, three-stage fan
LP-HP Compressor Stages: 0-6
HP-LP Turbine Stages: 1-1
Combustor Type: Annular
Engine Control: FADEC
Length: CTOL/CV: 220 in (5.59 m); STOVL: 369 in (9.37 m)
Diameter: 51 in (1.30 m)
Dry Weight: Unknown
Platforms: F-35 Lightning II (F-35A; F-35B; F-35C)
F135-PW-100: F-35A
F135-PW-400: F-35C
F135-PW-600: F-35B
Price/Unit Cost:
F135-PW-100: $13.06 million (in FY 2016)
F135-PW-400: $13.06 million (in FY 2016)
F135-PW-600: $30.82 million (in FY 2016)
First Run: Unknown
First Flight:
CTOL: December 15, 2006
STOVL: June 11, 2008
CV: June 7, 2010


Related post:

F-35 Lightning II: Details