Comparison and Development Analysis of F119-PW-100 & F135-PW-100 Khalid Mehrab, Md. Zamiul Alam, Shadman Tahmid Haque Department of Aeronautical Engineering Military Institute of Science and Technology khalidmehrab201922030@gmail.com, rafatridoy24@gmail.com, shadmantahmid1234@gmail.com Abstract This comparison contains the performance analysis between Pratt & Whitney F119 & the F135 while showing the developments it has achieved. The main quest for this article is to show the potential of these engines to develop a new generation of turbofan engines. While the F119 was built for supercruise flight, the F135 is more of a stealthy type as the successor of F119 to achieve the goals of Joint Strike Fighter (JSF) program. Even for a discontinued engine the F119’s design held potential capabilities for further improvement which has mostly been explored to bring the F135 and more upgrades are in the works. A few adjustments and further development on these designs may bring the engine for the sixth generation fighter aircrafts. Keywords- Pratt & Whitney F119, F135, Engine performance, F119-PW-100, F135-PW-400, F135PW-600, F135-PW-100. Introduction The F119 engine was created for the F-22 Raptor, however development was halted when the F-35 arrived with a developed engine (F135) from the F119. Thanks to thrust vector technology, the F119 gave the F-22 remarkable maneuverability. The F-135 is a development of the F119, resulting in a significantly more advanced F-35. The F119PW-100 was first tested on the ground in February 1993. During September 7, 1997, the engines flew for the first time on the F-22's maiden flight. There were 507 engines made in total[30]. Pratt aided the F119 Heavy Maintenance Center (HMC) at Tinker Air Force Base, Oklahoma, in performing the first Electronic copy available at: https://ssrn.com/abstract=4454666 depot overhaul of an F119 engine in 2013[1]. The F119 was available in four different configurations, three of which were prototypes. F119-PW-100: Production engine for the F-22A with larger fan and increased bypass ratio rated for 35,000 lbf thrust class. YF119-PW-100N: Prototype engine for the YF23. Fig- F-35[5] YF119-PW-611: Prototype engine for the X-35. Analysis YF119-PW-614: Prototype engine for the X-32. The F135 is an afterburning turbofan designed by Pratt & Whitney for the Lockheed Martin F-35 Lightning II single-engine strike fighter. In 2009, the first manufacturing engines were delivered [2]. The F135 was pitted against the GE/Rolls-Royce F136 for powering the F-35. The first operational production propulsion system was intended to be delivered in 2007 to the United States, the United Kingdom, and other international customers. The F135 is still being manufactured to power the F-35. For the three F-35 variants, the F-135 has three different engines. F135-PW-100: For the F-35A. Conventional Take-Off and Landing (CTOL) variant [3]. F135-PW-400: For the F-35C naval variant built with salt-corrosion resistant materials [3]. F135-PW-600: Used in the F-35B Short Take-Off Vertical Landing variant [3]. Fig- F-22 Raptor [4] Fig- F119 PW-100[6] The F119 is a twin-spool axial-flow low-bypass turbofan. It has a three-stage fan driven by a singlestage low pressure turbine and six-stage high pressure compressor driven by single-stage high pressure turbine. The F119 produces about 116kN thrust and 156 kN with afterburner. The two spools are counter-rotating, which results in weight savings due to the elimination of a row of stators. The requirement for the ATF to supercruise or fly supersonic without afterburners, results in a very low bypass ratio of 0.3 for the F119-PW-100 in order to achieve high specific thrust. The F119 has dual-redundant full authority digital engine control (FADEC) [7]. The three-zone afterburner or augmentor, contributes to the stealth of the aircraft by having fuel injectors integrated into thick curved vanes coated with ceramic radar-absorbent materials (RAM). These vanes replace the traditional fuel spray bars and flame holders and block line-of-sight of the turbines. The nozzle can vector ±20° in the pitch axis to improve aircraft maneuverability and consists two wedge-shaped flaps for stealth. The nozzles also contribute to lower infrared signature by flattening the exhaust plume and facilitating its mixing with ambient air through shed vortices [8]. The engine has a design life of 8,650 total accumulated cycles [9]. 2 Electronic copy available at: https://ssrn.com/abstract=4454666 Fig- F135[10] On the other hand, the F135 brought the target of the JSF program closer as it became the successor of F119. The F135 is a mixed-flow afterburning turbofan with a new fan and LP turbine [11]. It produces 128 kN thrust and 191 kN with afterburner. The lift for the STOVL version in the hover is obtained from a 2-stage lift fan (about 46%[12]) in front of the engine, a vectoring exhaust nozzle (about 46%[12]), and a nozzle in each wing using fan air from the bypass duct (about 8%[12]). These relative contributions to the total lift are based on thrust values of 18,680 lb. 18,680 lb and 3,290 lb. respectively [12]. In this configuration most of the bypass flow is ducted to the wing nozzles, known as roll posts. Some is used for cooling the rear exhaust nozzle, known as the 3-bearing swivel duct nozzle (3BSD) [13]. At the same time an auxiliary inlet is opened on top of the aircraft to provide additional air to the engine with low distortion during the hover[11]. A higher bypass ratio increases the thrust for the same engine power as a fundamental consequence of transferring power from a small diameter propelling jet to a larger diameter one [14]. When the F135 is in the hover using the significantly increased bypass ratio from the lift-fan, the thrust augmentation is 50% [12] with no increase in fuel flow. Thrust augmentation is 52% [12] in conventional flight when using the afterburner, but with a large increase in fuel flow. The transfer of approximately 1⁄3 [15] of the power available for hot nozzle thrust to the lift fan reduces the temperature and velocity of the rear lift jet impinging on the ground [15]. The F-35 can achieve a limited 100% throttle cruise without afterburners of Mach 1.2 for 150 miles [16]. Like the F119, the F135 has a stealthy augmentor where traditional spray bars and flame holders are replaced by thick curved vanes coated with ceramic RAM. Afterburner fuel injectors are integrated into these vanes, which block line-of-sight of the turbines, contributing to aft-sector stealth. The axisymmetric nozzle consists of fifteen partially overlapping flaps creating a sawtooth pattern at the trailing edge. This creates shed vortices and reduces the infrared signature of the exhaust plume. The effectiveness is reportedly comparable to that of the F119’s wedge nozzles, while being substantially more cost effective and lower maintenance [17]. The engine uses thermoelectricpowered sensors to monitor turbine bearing health[18]. Engine reliability and ease of maintenance have been achieved for the F135. The engine has fewer parts than similar engines, which improves reliability. All line-replaceable components (LRCs) can be removed and replaced with a set of six common hand tools [19]. The F135’s health management system is designed to provide real time data to maintainers on the ground. This allows them to troubleshoot problems and prepare replacement parts before the aircraft returns to base. According to Pratt & Whitney, this data may help drastically reduce troubleshooting and replacement time, as much as 94% over legacy engines [20]. The first stage fan from the F119 engine for the lift fan. The engine fan and core from the F100-220 were used for the core of the demonstrator engine and the larger low-pressure turbine from the F100-229 was used for the lowpressure turbine of the demonstrator engine. The larger turbine was used to provide the additional power required to operate the lift fan. variable thrust deflecting nozzle was added to complete the lift-fan technology and led to the development of the current F135 engine [21]. Topic Length Diameter F119-PW-100 16 ft 11 in (516 cm) 46 in (120 cm) Dry weight Bypass ratio Maximum thrust 3,900 lb (1,800 kg) 0.30:1 Military thrust = 26,000 lbf (116 kN) With afterburner = 35,000 lbf (156 kN) Thrust to weight ratio 6.7:1 (dry), 9.0:1 (afterburning) F-135-PW-100 220 in (559 cm) 46 in (117 cm) max., 43 in (109 cm) at the fan inlet 3,750 lb (1,701 kg) 0.57 : 1 Military thrust =28,000 lbf (128 kN) with afterburner=43,000 lbf (191 kN) 7.47:1 military thrust 11.47:1 augmented 3 Electronic copy available at: https://ssrn.com/abstract=4454666 Compressor 3-stage fan, 6-stage high-pressure axial flow compressor Turbine 1-stage highpressure, 1-stage lowpressure counter rotating turbine Annular combustor 2D vectoring convergentdivergent Combustor Nozzle 1963 knots 3,635 Km/h 3-stage fan, 6stage highpressure axial flow compressor 1-stage highpressure turbine, 2stage low-pressure turbine Annular Thrust vectoring nozzle of the SVTOL variant, improved afterburner 1043 knots 1,932 Km/h Maximum cruise speed for installing in F22 and F-35 respectively Rear temperature Turbine Inlet Temperature 2000°F 3,600 °F 3,000 °F (1,649 °C; 1,922 K) Fuel tank capacity 2400 gallon 9085 litre 3,600 °F (1,980 °C; 2,260 K) 2760 gallon 10448 litre engine and reduce maintenance costs. The goal of Block 2 is to work with the US Air Force’s Adaptive Engine Transition Program, with the intention of introducing technology for an engine rated at 45,000 lb. of thrust, for installation in a sixth-generation fighter. References [1] PRNewswire. "Pratt & Whitney, U.S. Air Force Complete First Depot Overhaul of an F119 Engine". providencejournal.com [2] F135 Engine Exceeds 12,000 Engine Test Hours as Pratt & Whitney Prepares to Deliver First Production Engines" (2009). Pratt & Whitney press release. [3] DP Staff Writer (October 5, 2019). "Pratt & Whitney Awarded with $5.7B F135 Production Contract" [4] https://en.wikipedia.org/wiki/Lockheed_Martin_F22Raptor#/media/File:F22_Schematics.jpg Table- Comparison of F119 & F135 [22][23][ 24][25][26] Conclusion The sectors which were developed of the F119 to bring the F135 are weight, maximum thrust with increased bypass ratio, temperature resistance, vertical landing and take-off technology, lift-fan concept, engine reliability and efficiency, stealthy augmentor, low pressure turbine, fuel tank capacity. The change in these sectors brought the F135 closer to the JSF program, showing the potential of the F119 engine as even further improvements were done in 2017 to the F135. At the end of May 2017 Pratt and Whitney announced the F135 Growth Option 1 had finished testing and was available for production. The Growth Option 1 offers an improvement of 6-10% thrust across the F-35 flight envelope while also getting a 5-6% fuel burn reduction. The upgrade requires the changing of the power module on older engines. In June 2018, Growth Option 2.0 was announced by United Technologies, parent company of Pratt &Whitney to help provide increased power and thermal management system (PTMS) capacity, providing options for operators for instance if they are wishing to upgrade to heavier weapons. A twoblock improvement plan for the F135 engine is in motion. The goals of Block 1 are a 7–10% increase in thrust and a 5–7% lower fuel burn. The plans include better cooling technology for turbine blades which this will increase the longevity of the [5] https://media.defense.gov/2014/Mar/11/200078382 6/-1/-1/0/140310-F-NG006-007.JPG [6] https://www.nationalmuseum.af.mil/shared/media/ photodb/photos/051117-F-1234P-022.jpg [7] https://www.forecastinternational.com/archive/disp _pdf.cfm?DACH_RECNO=901 [8] Katz, Dan (7 July 2017). The Physics And Techniques Of Infrared Stealth [9] "Pratt & Whitney's F119 Demonstrates Full Life Capability". Pratt & Whitney. 10 September 2010. Retrieved 12 May 2019. [10] https://www.jsf.mil/images/gallery/sdd/f135/sdd_f1 35_018.jpg [11] http://www.codeonemagazine.com/article.html?ite m_id=28 [12] https://web.archive.org/web/20150924083346/http: //www.pw.utc.com/Content/F135_Engine/pdf/b-24_me_f135_stovl.pdf [13] http://www.codeonemagazine.com/article.html?ite m_id=137 [14] V/STOL by Vertifan" William T. Immenschuh, Flight International, 1 October 1964 [15] The Shaft Driven Lift Fan Propulsion System for the Joint Strike Fighter" Paul M. Bevilaqua, American Helicopter Society 53rd Annual Forum, Virginia Beach, April 29-May 1, 1997 4 Electronic copy available at: https://ssrn.com/abstract=4454666 [16] https://web.archive.org/web/20121108143240/http: //www.airforcemagazine.com/MagazineArchive/Pa ges/2012/November%202012/1112fighter.aspx [17] https://aviationweek.com/defense/physics-andtechniques-infrared-stealth [18] http://www.rfidjournal.com/article/articleview/847 8/1/1/ [19] https://web.archive.org/web/20190511192645/http: //www.pratt-whitney.com/vgn-exttemplating/v/index.jsp?vgnextoid=2e35288d1c83c 010VgnVCM1000000881000aRCRD&prid=95068 129982de010VgnVCM100000c45a529f [20] Rajagopalan, R., Wood, B., Schryver, M. (2003). Evolution of Propulsion Controls and Health Monitoring at Pratt and Whitney. AIAA/ICAS International Air and Space Symposium and Exposition: The Next 100 Years. 14–17 July 2003, Dayton, Ohio. AIAA 2003-2645 [21] https://arc.aiaa.org/doi/abs/10.2514/1.15228 [22] https://web.archive.org/web/20150924005241/http: //www.f135engine.com/docs/B-24_F135_SpecsChart.pdf [23] https://www.tinker.af.mil/News/ArticleDisplay/Article/385150/f135-engine-depot-standup-has-started/ [24] http://memagazineselect.asmedigitalcollection.asm e.org/article.aspx?articleid=2683357 [25] https://www.webcitation.org/6REwxrOCV?url=htt p://www.pw.utc.com/F119_Engine [26] https://aerocorner.com/comparison/eurofightertyphoon-vs-f-22-raptor/ [27] http://www.prnewswire.com/news-releases/pratt-whitney-validates-growth-option-for-f135-engine300466212.html [28] https://www.airforce-technology.com/news/prattwhitney-launches-growth-option-2-0-upgradef135-engine/ [29] Norris, Guy, Power plan, Aviation Week & Space Technology, April 13–26, 2015, p.26 [30] https://www.flightglobal.com/news/articles/prattwhitney-to-deliver-last-f-22-raptor-engine-381145/ 5 Electronic copy available at: https://ssrn.com/abstract=4454666