Eurojet EJ200

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Issued EJ200 from the side

The Eurojet EJ200 is a turbofan engine from the European manufacturing consortium Eurojet Turbo GmbH. The engine is based on the British XG-40 and allows the Eurofighter Typhoon to maneuver continuously in supersonic conditions. For this purpose, the dry thrust (measure of the thrust of an engine without an activated afterburner) was significantly increased compared to the Turbo-Union RB199 with the same dimensions. Another objective was low life cycle costs . For this, the maintenance intervals was dispensed with the traditional method, and instead a modern engine monitoring unit ( english Engine Monitoring Unit , shortly EMU) installed to be able to double the operating time without compromising security.

history

First concepts

When the NATO military planners were thinking about a new generation of combat aircraft in the 1980s, they came to the conclusion that future combat aircraft would have to operate continuously in supersonic capacity in order to increase their survivability against enemy fighter jets and guided missiles. It was required to still fly high g-forces even at Mach 1.2-1.6 , and to be able to cover longer distances in supersonic flight. The key to this would be engines with a low bypass ratio and high dry thrust, which should be at least 50% above the dry thrust of contemporary turbojets. To achieve this goal, a more efficient compressor and higher turbine inlet temperatures would be required. To exchange knowledge, the NATO Flight Mechanics Panel (FMP) held a symposium on the subject of Technology for Sustained Supersonic Cruise and Maneuver in October 1983 .

The initial idea of ​​the European Fighter Aircraft (EFA) was also aimed at creating a fighter aircraft that can maneuver permanently in supersonic conditions in order to increase the effectiveness and survivability of the weapon system. Compared to the American developments, however, the requirements on this side of the Atlantic were different. While the Advanced Tactical Fighter (ATF), as a pure air superiority fighter, required an engine for long-term supersonic march flight without an afterburner, the EFA should also be used for air-to-ground missions, so that the engines would work most of the time in partial load operation. While the ATF engine optimized for Supercruise would have a bypass ratio of 0.3: 1 or less and twice the dry thrust of the Pratt & Whitney F100 , the engine core of the EFA engine had to be relatively smaller in order to enable economical subsonic flight. Increases in thrust in supersonic and aerial combat would therefore be more often dependent on the afterburner, which is why the specific consumption in afterburner operation should be particularly reduced.

Although politicians also discussed using a common European engine, it became apparent in 1985 that the Turbo Union companies Rolls-Royce, MTU and Fiat would deliver the engine for the EFA. France insisted on building the complete engine and requested that it be based on the Snecma M88 . The Eurofighter partner countries estimated the state of the art of the M88 at the level of the General Electric F404 of the F / A-18 , which seemed out of date for the EFA. The UK insisted on using the XG-40, which performed significantly better, and was also willing to outsource parts of the work to partner countries. MTU and Fiat would contribute technologies to the joint engine that they had already demonstrated in the Turbo-Union RB199 development programs.

The ACME program

The development of the Advanced Core Military Engine I (ACME I) began in 1982 and was intended to provide the technological basis for future fighter jet engines. The United Kingdom Department of Defense (MOD) was 85% funding and Rolls-Royce was 15%. Although the Advanced Core Military Engine was only funded by Great Britain, it was already clear at the time that the engine would power the EFA. The XG-40 engine developed from this in 1984 was to demonstrate a thrust-to-weight ratio of 10: 1, later this value was to be increased to 12: 1. The XG-40 would be fundamentally different from the RB199: While the RB199 was designed for subsonic cruise flight at low altitudes, the XG-40 should be designed for a flight envelope with armaments from Mach 0.9 to Mach 1.6 in 10 to 13 km Height can be optimized. To achieve this goal, the dry thrust had to be increased by 80% to around 70 kN compared to the RB199. The afterburner thrust should be increased by 40%, to 90 to 100 kN. In the dry run, the specific consumption of the RB199 should be maintained, while the specific consumption of the afterburner should be reduced by 30%.

A Turbo-Union RB199 in the Bundeswehr Air Force Museum

From 1982 onwards, the Federal Republic of Germany and Great Britain financed three more RB199 demonstration programs. Each of these programs increased the engine thrust by 20% and should reduce the specific fuel consumption of the afterburner. The Demo 1A engine was only built by Rolls-Royce and was intended to test brush seals, powder metallurgy and single-crystal turbine blades. The engine had the extended jet pipe of the RB199 Mk104. This led to the XG-20 engine, which was managed by MOD, Rolls-Royce and Turbo-Union. The XG-20 was equipped with an improved low-pressure compressor and a new high-pressure turbine, as well as the extended jet pipe of the Mk104 and a FADEC. The XG-20 was tested at Rolls-Royce in November 1984, where it was able to provide 15% more dry thrust and 20% more afterburner thrust. The third engine was Demo 20 , which ran at MTU in April 1985. This was a shortened version with a new FADEC. These improvements should benefit the RB199 development to be used in the tornado or temporarily in the EFA. For the Hawker Siddeley Harrier , an XG-15 engine with 15 to 20% more thrust (about 110 kN) was planned, which would have made the aircraft supercruisable at Mach 1.2-1.3. With 30% more thrust thanks to XG-40 technology, even 126 kN dry thrust would have been conceivable.

The British XG-40 engine should have two instead of three shafts compared to the RB199 and a thrust-to-weight ratio of at least 10: 1. In the maximum expansion stage, the engine should be much more advanced than the French Snecma M88, with turbine inlet temperatures that correspond to the maximum of the stoichiometric kerosene-air combustion. After the program started in 1982, testing of the entire first engine was planned for 1986. The second, more advanced engine with a thrust-to-weight ratio of 12: 1 was to be completed later. The XG-40 program was divided into five parts: technology (component improvement), engine performance, endurance, performance increase and weight reduction. The Rolls-Royce ACME demonstrator made a significant contribution to the realization of the XG-40, while FADEC, compressors and seals came from the RB199 development programs. The XG-40 should provide a scalable engine core for various thrust requirements.

Testing of the XG-40 core, consisting of a five-stage compressor and a single-stage turbine, began in March 1986. Technological innovations included a more powerful compressor and turbine, single-crystal turbine blades with a low density, advanced seals and ceramic coatings in the combustion chamber and turbine . The aerodynamics of the turbine was previously simulated on a 0.87: 1 plastic model. Since the engine has been optimized for air combat, it should consume less kerosene in the afterburner, the turbine inlet temperatures should be 150-200 ° C higher than the RB199, and the bypass ratio should be less than half that. In order to achieve this goal, a lot has been invested in the development of single crystal airfoils. Furthermore, a diffuser, which untwists the exhaust gas jet at the end of the gas turbine, was placed directly behind the low-pressure turbine. This cobalt alloy component was forged from one piece; very thin titanium cases were also used. The three-stage fan, which originally had a compression ratio of 3.4: 1 and required stops against fluttering, was later able to achieve 3.9: 1 without stops. Different numbers of stages were examined for the compressor, five of which proved to be the optimal solution. For research purposes, the compressor had adjustable stator blades on the first stage and inlet guide vanes , although the production version of the engine was always planned without it. The compression ratio was 6.5: 1. The combustion chamber built on the experiences of the RB199, and the single-stage high pressure turbine used ceramic coatings in addition to cooled adjustable guide vanes. An in-house nickel alloy was used in tests, but the rotor was designed in such a way that denser alloys could also be used. The high pressure turbine used a passive tip clearance control, an active one was later tested. The low pressure turbine was also single-stage, with adjustable guide vanes. The high turbine outlet temperature caused problems during the development of the afterburner. Various cooled metal structures and uncooled ceramics were tried. The nozzle was again constructed similarly to the RB199. Blisks and hollow blades were only used in the second engine. The oil cooling was built conventionally with pumps, whereby an advanced system was planned that would work with centrifugal forces. Rolls-Royce also developed an "Electronic Engine" simulator to debug the software for the FADEC . This was particularly complex because the XG-40 had adjustable guide vanes and outlets in the high pressure compressor, adjustable guide vanes in front of the high pressure turbine, high pressure valves for turbine cooling and an adjustable thrust nozzle at the rear.

While the XG-40 was not specifically developed as an Advanced Fighter Engine for the EFA, parameters such as the bypass ratio of 0.4: 1 were carefully chosen for this purpose. Nevertheless, one of the development goals of the XG-40 was that this engine had to get along with the installation dimensions in a Panavia Tornado . The second XG-40 successfully completed the ACME-I program with 200 hours of operation and 4000 cycles in June 1995. Then began the ACME II program, which was to research the technologies for an engine with a thrust-to-weight ratio of 20: 1. Investigations dealt with a further weight reduction of compressors and turbines, ceramic fiber composites and variable bypass flow ratios ( Variable Cycle Engine ). ACME II (L) explored thrust vector control, while ACME II (T) and ACME II (C) explored high pressure engine cores. However, the development of the XG-1100 engine based on it, like the associated Future Offensive Air System , was later discontinued.

Eurojet and thrust vector technology

The British ultimately prevailed in the dispute over an EFA engine. In 1986 the founding of Eurojet Turbo was announced at the Farnborough International Airshow . Rolls-Royce and MTU each took over 33% of the shares, the Italian Avio 21% and the Spanish company ITP 13%. Rolls-Royce was to be responsible for combustion chamber systems, high pressure turbines and condition monitoring, MTU Aero Engines for low and high pressure compressors as well as the Digital Engine Control and Monitoring Unit (DECMU), Avio for low pressure turbine, afterburner system, transmission, air and oil system, and ITP for thrust nozzle , Afterburner housing, exhaust diffuser, bypass housing and add-on parts.

The engine should be based on the XG-40, but not have a swirl regulator in the fan. In addition, Germany insisted on a convergent-divergent nozzle to improve flight performance at high Mach numbers. The EFA should reach a maximum speed of Mach 2.2, which is why a thrust of over 90 kN with an engine mass of 900 to 1000 kg and a thrust-to-weight ratio of 10: 1 was targeted. The compression ratio should be over 25: 1 and the bypass ratio should be around 0.4: 1. Since the core engine of the XG-40 was to be used, the performance goals were conservative, whereby Eurojet was obliged to provide a thrust increase of 15% for the EJ200 by compressing the compressor more strongly. In return, a fixed price contract was concluded. It was already clear at that time that the EJ200 would not have been developed in time for the flight tests of the Eurofighter, so that an RB199 or F404 was being discussed as an interim solution.

The first parts for the EJ200 were in production in 1988, and the first ignition should take place at the end of 1989. Three Design Verification Engines (DVE) and a separate high-pressure compressor were built for development. The DVE were heavier than the production models because they were not weight-optimized. The DVE tests were finished in 1991, by which time the engines had already completed 650 hours of testing, 80 of which were altitude tests. 60% of the altitude tests were carried out at the University of Stuttgart. The windmilling was tested, the consumption parameters checked, etc. In total, the afterburner was switched on 2880 times and switched between idle, maximum and idle 8700 times. To the astonishment of those involved, the 1991 program was a year ahead of schedule. In the planning phase it was discussed whether a flying test stand would make sense for development. Ultimately, however, the decision was made against it because only minor benefits were expected from it. A conversion of the EAP for the EJ200 engine tests was therefore rejected. The possibility of installing the EJ200 in the ADV Tornado was examined for later commercial use, and it turned out to be positive. During development, the fan and high-pressure compressor of the DVE engines still suffered from vibrations that could be eliminated. In 1991 the pre-series was just around the corner and details of the production were discussed. Twelve Full Scale Development (FSD) engines were built, the biggest difference to the DVE engines being the loss of mass. In 1992 the tests with the FSD engines were finished, and in mid-1992 the approval for the Eurofighter should take place.

The first analyzes of thrust vector control (SVS) were started by ITP in 1991, and the first study was carried out in 1994–1995. At the beginning of 1994 DASA, which was responsible for the control laws of the Eurofighter flight control system, worked on incorporating parts of the control laws of the Rockwell MBB X-31 into the Eurofighter project. Germany advocated equipping the Eurofighter with thrust vector technology later to increase combat value. Eurojet Turbo emphasized that this was not an official requirement, but that MTU had advertised it. In early 1995 the Eurofighter consortium rejected the development of an alternative flight control system (FCS) based on the X-31. Although technically feasible, the current FCS met the aircraft's needs and requirements. It was feared that a radical change at this point would cause time and cost overruns. The flight tests of the EJ200 began on June 4, 1995 in the third Eurofighter prototype DA3.

The X-31 was intended to serve as a flying test stand for the EJ200 thrust vector nozzle

In 1995, ITP and MTU began the technology demonstration phase for the thrust vector nozzle. The first prototype was manufactured from 1996 and tested for the first time on July 30, 1998. This made the EJ200 the first Western European jet engine with thrust vector control (SVS). Germany wanted to continue to use the X-31 to get the thrust vector technology into the Eurofighter. In early 1998, it was expected that a memorandum of understanding on the X-31-VECTOR program would be signed in March . The nozzle and air data system should be revised. Aloysius Rauen, head of DASA's military division, wanted to see the results of the VECTOR program implemented in the Eurofighter EF2000 or JAS 39 Gripen in order to catch up with Russia in terms of thrust vector control. In February 1998 the two-seater DA4 carried out “supercruise” flights with the Eurojet for the first time. Meanwhile, the EJ200 thrust vector engine was tested according to a strict test program in Spain in 2000 in the altitude test bench of the University of Stuttgart .

At the beginning of 2000 the plans became more concrete: the US Navy held talks with ITP about the integration of the EJ200 thrust vector nozzle into the X-31. It was also envisaged that Spain could rent test time on the aircraft, or that the nozzle tests could be done according to the VECTOR program. At the end of 2000, an agreement between the USA, Spain and Germany was about to be concluded. It should be agreed that from the end of 2002 the thrust vector nozzle of the EJ200 will be tested in the X-31. This was intended to encourage the Eurofighter partner countries to order tranche 3 with thrust vector engines. ITP had already extensively tested the nozzle, but no Eurofighter was available for test flights. The cost of about $ 60 million to install an EJ200 with SVS in the X-31 was to be borne mainly by the Spanish government, the rest by Eurojet Turbo GmbH. The NATO EF 2000 and Tornado Development, Production & Logistics Management Agency approved the delivery of the engines, whereby these should be diverted from the Spanish Quantum. The US Navy would only be responsible for managing the flight tests, but the Europeans were concerned about the EJ200's technology transfer to the US. At this point in time, the industry had not yet agreed on the exact integration of the thrust vector technology into the Eurofighter. The ITP project manager, Daniel Ikaza, suggested initially only enabling pitch control (2D) in the aerodynamic flight range, and later enabling 3D vector control even after a stall through software updates to the flight control software. The director of NETMA was convinced of the benefits of the thrust vector technology and saw an integration into the Eurofighter for tranche 3 and beyond. In mid-2001, further talks were held with the Spanish Ministry of Defense about the installation of the EJ200 with SVS in the X-31, but they were unsuccessful.

On November 21, 2002, the 323rd test flight with pre-series engines around 100 kilometers south of Madrid crashed the two-seater prototype DA6. At the time the afterburners were ignited - afterburner tests were carried out - one engine suffered a stall . At an altitude of 40,000 ft and at Mach 0.7, the crew tried to reignite the engine, and the second failed. Knowing that the Development Aircraft (DA) did not have a Ram Air turbine and that they would lose control of the aircraft in a few seconds due to a loss of hydraulic pressure, EADS CASA chief test pilot Eduardo Cuadrado and Ignacio Lombo from the Spanish Air Force shot themselves immediately after the Failure of the second engine from the aircraft. The flight tests with the DAs were only continued 24 hours later when it became clear that the error only affected the particular engine model of DA6.

On June 13, 2003, the first series-produced Eurofighter was finally presented to the public. The Bundeswehr accepted the machine on August 4th of the same year. The so-called missile launch tests ( English missile firings ) required under the engine certification for military jets, and were at the Munich ground test of the MTU and the altitude test of the 2004 University of Stuttgart conducted. A special burner was installed in front of the intake of the EJ200 engine and proof of function was provided without real flights. For future developments, a reduction in service life costs, reduced fuel consumption and an increase in thrust of up to 30% are being investigated. In 2011 the Eurofighter Jagdflugzeug GmbH considered financing the test flights for the SV engine. But this did not happen, presumably due to a lack of customer interest.

technology

In addition to good drive performance, value was also placed on ease of maintenance and repair, as well as low total operating costs. Replacing a Eurojet engine takes 4 people in less than 45 minutes. The Engine Health Monitoring System (EHMS), consisting of EMU and DECU, controls the engine status. This system enables so-called "on condition" maintenance, ie without the need to adhere to periodic maintenance intervals. The maintenance team works with a Portable Maintenance Data Store (PMDS) computer, with which engine malfunctions can be read out and in which the "life story" of each engine is recorded. All components are designed for a long service life, 6000 hours for the cold parts and up to 3000 hours for the hot parts. The engine is also very resistant to bird strikes; In tests, a “flock” of eleven dead birds weighing 85 grams each was sucked into the engine, and it continued to run without impairment.

Jet engine

The engine core, consisting of the combustion chamber, turbines and afterburner, is derived from the XG-40. The compressor was newly developed by MTU and Rolls-Royce and is therefore different from the XG-40. According to Colin Green, then Managing Director of Eurojet, the main difference between the Eurojet and the Pratt & Whitney F119 is that the EJ200 is an all-metal engine. In contrast to the ATF engine, no structural ceramics or C / C composites are used. The integration of ceramics and composite materials in the Eurojet is conceivable for future increases in performance. Compared to the Turbo-Union RB199 , the EJ200 requires 37% fewer parts (1800 instead of 2845) and develops significantly more thrust with the same dimensions. The thrust-to-weight ratio of the EJ200 is 9.5: 1 with an engine weight of 1035 kg. The originally planned record of 10: 1, however, could not be achieved because the high-pressure compressor of the EJ200 was heavier than the target.

Turbofan

The engine's compressor

The EJ200 is a twin-shaft engine with a low bypass ratio (“leaky turbojet”). The low bypass ratio of 0.4: 1 was chosen for high dry thrust and good propulsion efficiency in the supersonic area. A larger core with a lower bypass ratio (see M88 and F119 with ≤0.3: 1) would have increased the engine weight and worsened the specific consumption. Since the outside diameter of the engine cannot be changed later, a bypass ratio of over 0.3: 1 had to be selected so that later versions can use a larger engine core. The incoming air is compressed by a low pressure compressor in three stages to a pressure ratio of 4.2: 1. The high and low pressure compressors are manufactured using what is known as blisk technology, whereby the compressor disks and blades consist of one piece, which reduces weight. Later versions will increase the print ratio to 4.8: 1. During the development, new technological territory was broken by manufacturing the blisks using the friction welding process. The titanium alloy blades are more than twice the size of the Turbo-Union RB199 and are hollow. The following high-pressure compressor with 3D blading and supercritical compressor blade profiles generates a pressure ratio of 6.2: 1 with just five stages and is therefore at the forefront of this sophisticated technology worldwide. The engine manages with only one set of swirl regulators in the high-pressure compressor. The two compressors rotate in opposite directions to each other and thus generate a total pressure ratio of up to 26: 1. Air and fuel are burned together in the annular combustion chamber , and fuel is injected using the air spray method. The combustion chamber is accessible with endoscopes . The turbine inlet temperature is around 1800  Kelvin . The high and low pressure turbines each consist of one stage and use air-cooled single crystal blades made of a nickel alloy with a ceramic coating of nickel, chromium and yttrium as a thermal insulation layer . This coating must be checked regularly for any damage. The turbine uses Active Tip Clearance Control . Air flows through the engine housing in order to keep the gap between the housing and rotor stages constant, which increases efficiency and reduces fuel consumption. Another novelty is the rotating oil tank developed by Avio , which guarantees positive g-loads in the oil tank even with negative g-accelerations of the aircraft, and thus reliable lubrication of the engine during all possible flight maneuvers.

Afterburner

Since the exhaust gas temperatures of the low-pressure turbine are much higher than with older engines, the flame holder of the afterburner must be cooled by the bypass air. Due to the small bypass flow, around half of the bypass air must be used for cooling, so that only the other half is available for combustion in the pipe. The afterburner is ignited using the "hot shot" method. If the Augmentor is only operated at part load, the fuel is sprayed into the core flow, since the combustion conditions are best there. Only when stoichiometry is reached is additional fuel injected into the bypass flow.

Thrust nozzle

The convergent-divergent nozzle

The afterburner is followed by an adjustable convergent-divergent nozzle without thrust vector control. Originally only a convergent nozzle was examined - the engine should be as simple and light as possible - but the requirements for intercepting could not be met. Despite the additional mass, it was finally decided to use an adjustable convergent-divergent nozzle, as this reduced consumption in supersonic cruising flight and increased endurance by 25%. This also made it possible to reduce the air resistance of the aircraft tail.

ITP also developed a 3D thrust vector nozzle for the EJ200, with MTU developing the electronic control as a partner. The system consists of three rings, which are controlled by four hydraulic actuators . The thrust vector control could also only use three actuators, but then the independent control of the exit area would have to be dispensed with. The three rings are gimbaled and allow the control of three degrees of freedom: pitch angle, yaw angle and nozzle exit area. If the outer ring is divided into two, the nozzle throat diameter is added as a fourth degree of freedom. This more complex arrangement allows the net thrust in the Supercruise to be increased by up to 7% through optimized aerodynamics, and the afterburner thrust when taking off by 2%. The prototype was able to deflect the thrust jet by 23 ° at 110 ° / s, whereby thanks to the joints, 30–35 ° deflection angles can also be achieved. By cleverly balancing the nozzle blades, part of the force of the exhaust gas jet is used to support the deflection, so that the actuators have to perform 15% less. The thrust vector control is intended to reduce the trim resistance, shorten the take-off and landing distance and increase flight safety through more control surfaces, which leads to a fuel saving of around 3% in a typical combat mission. In addition to increasing maneuverability in aerodynamic flight, the aircraft can also be steered in a controlled manner after a stall.

Digital Engine Control and Monitoring Unit

The engine is controlled via the Digital Engine Control and Monitoring Unit (DECMU) . The fuel-cooled DECMU was mounted on the EJ200 engine from tranche 2 and is produced by MTU. Tranche 1 aircraft have separate systems with the DECU and the EMU, the TVCU was only used for thrust vector test engines. The DECMU combines all three systems in the DECU, reduces the volume by 5 liters and the weight by 5 kg and has a 20% increase in computing power. The device is hardened against electromagnetic pulses and can be used from −40 ° C to +125 ° C.

The challenge in developing the DECMU was that the weight and dimensions of the DEMU had to be maintained. For this purpose, another computer system was installed on the existing dual processor cards, also to ensure the separation between flight-critical control software and monitoring software. The integration density had to be increased significantly, otherwise 50% more space would have been required on the board. In addition, the discrete pressure and oil level monitoring has been replaced by continuous measurement. This means that the oil level can always be checked while the engine is running and does not have to be read as an additional maintenance measure at the end of a flight. Five freely configurable control loops allow the introduction of thrust vectorization, pitch control, independent A 8 / A 9 control, etc. In the following section, all three systems are explained separately:

Digital Electronic Control Unit

Engine with flanged digital engine controller (gray box)

The digital electronic control and regulating unit ( english Digital Electronic Control Unit , just DECU ) monitors its hardware and other control components and detects incidents that affect engine operation. The DECU is mounted on the jet engine and cooled with its kerosene. It consists of two identical lanes ( German, for example, lanes, lanes) that communicate with each other internally so that each lane can access the data of the other. Both monitor the engine functions, including the fuel flow into the combustion chamber and in the afterburner, the adjustment of the assembly and diverging nozzle and the angle of the swirl control (engl. Variable guide vane angle , dt. About a variable angle of the vane ) to the required thrust to be achieved without exceeding limit values. Integrated test facilities (BIT) were installed for control purposes in order to monitor the condition of the engine and to reduce its functionality in the event of damage. The "Initiated BIT" are carried out before and after an engine run or at the request of the "Maintenance Data Panel (MDP)", the "Continuous BIT" during operation.

DECU Initiated BIT DECU Continuous BIT
RAM and PROM memory Sensor function tests
RAM addressing Test the input signal
Time and interrupt logic External bus
Interface calibration DECU CPU test
Hardware / software error Short circuits
Speed ​​controller Spark plugs, actuators

The DECU is connected directly to the engine and to the cockpit via the double redundant flight control system bus. Errors in the BIT routine which lead to a lane change, the revocation of a control command or a loss of control are displayed in the cockpit. The DECU also identifies faults in the fuel system, oil flow and hydraulic system (filter clogging, too low pressure, too low level, too high temperature). The only error message that the EMU sends directly to the cockpit via the DECU is a vibration warning. The DECU also looks out for unexpected loss of performance in engine operation. If this happens before take-off, a warning message will be displayed in the cockpit.

Engine monitoring unit

Eurofighter Typhoon with ignited afterburners

The engine monitoring unit ( english Engine Monitoring Unit , shortly EMU) divides all incidents and injuries with and monitored vibrations particles in the oil, engine performance and lifetime consumption of the engine components and is the central element of the data processing of the EJ200. The EMU is air-cooled in the avionics bay of the Euro Fighter installed, from tranche 2 it was integrated into the DECMU, which frees up the space in the avionics bay. It also consists of two identical lanes that monitor the Typhoon's two engines. The EMU and the DECU are connected to each other via a MIL-STD-1553 bus. The EMU also performs Initiated / Continuous BIT operations for itself and its sensors, for example the front and rear vibration sensor and the oil sensor ( English Oil Debris Monitoring ).

The EMU contains a logic that takes snapshots of engine parameters and compares them with flight parameters. This determines the thrust in flight, and the data obtained in this way is used to control the engine: the maximum dry thrust remains constant for the entire service life of the engine. This temperature and speed limit creates safety margins in order to increase the service life. If the safety margin falls below a certain value, maintenance is necessary. The temperature and speed limit can also be removed so that the DECU allows the engine to operate at maximum power. This setting is known as the war setting .

The EJ200 is equipped with two acceleration sensors, one in the front and the other in the back of the engine housing. These sensors detect vibrations in the engine and can localize the source of the malfunction, whether it is the compressor or turbine, for example, or whether the high-pressure or low-pressure part is affected. The data from the sensors are recorded and given a time stamp so that the software can recognize possible long-term increases and, if necessary, report the need for maintenance. A warning message is sent to the cockpit in the event of unusually strong vibrations.

The EMU monitors the service life of the critical components of the EJ200 depending on the possible failure in real time. With the help of sensors that measure the flow rate, temperatures and pressures, the temperature distribution and mechanical load on the components is calculated. The table lists the sensors and the possible failure of the component for which the service life is calculated by the engine monitoring unit:

Component Number of sensors Failure
Low pressure compressor 14th Fatigue fracture
High pressure compressor 34 Fatigue fracture
Combustion chamber 2 Fatigue fracture
High pressure turbine 2 (on blades) Creep , thermo-mechanical fatigue
High pressure turbine 13 (other) Fatigue fracture
Low pressure turbine 1 (on blades) Crawl
Low pressure turbine 8 (other) Fatigue fracture

The oil monitoring system also measures the number of metal particles in the lubricating oil in order to detect gear and bearing damage at an early stage. For this purpose, a magnetic sensor was integrated into the oil filter in order to catch and detect metal particles. The sensor consists of a magnetic coil that is part of an oscillating circuit . The oil monitoring system is also mounted on the jet engine in Tranche 1 aircraft and communicates there with the EMU in the avionics bay via the Digital Direct Link (DDL). From tranche 2 it is connected to the DECMU on the engine. The sensor sends a signal which corresponds to the collected mass. A sudden increase in mass means that a large particle has been trapped, so the sensor can distinguish between small and large particles (splinters). From the increase in mass at the detector over time, it can be calculated whether the wear on the engine components is normal.

Thrust vector control unit

Prototype of the thrust vector nozzle

The thrust vector control unit ( English Thrust Vector Control Unit , just TVCU) was used by MTU in the initial phase of the thrust vector development, while ITP was responsible for the nozzle. The TVCU was connected to the DECU via a MIL-STD-1553 bus. It controlled the actuators, took into account the aerodynamic limits of the nozzle surfaces and monitored the condition of the nozzle. Test devices were still integrated during the engine and TVCU tests. The thrust vector control unit consisted of two identical lanes that controlled the 3D thrust vector nozzle. Both lanes were structured identically: the bus data was sent to a Motorola MC68332 control computer , which was responsible for communication, kinematics calculation of the nozzle, limitation of geometry and vector rate, monitoring, deactivation in an emergency and test procedures. This shared a dual-port RAM with a second microcontroller, the output computer. He was responsible for the control and activation of the actuators. The control computers and output computers in each lane were connected to the other via a data link, among other things for synchronization.

Attached to an EJ200 with a thrust vector nozzle, this configuration was extensively tested in the laboratory and on the jet engine test bench. Since the flight control computer of the Eurofighter only command lateral forces and thrust, these were calculated for the respective nozzle position using numerical fluid mechanics and integrated into the thrust vector control unit. The TVCU now calculated the nozzle position for the required lateral forces with an accuracy of over 95%. In the event of system errors, the thrust vector was commanded to index position (0 ° / 0 °) by the TVCU. If the A 8 control should fail, a loss of afterburner function was also found. The thrust vector control unit could be used from 0 ° C to +40 ° C, i.e. only in a laboratory environment.

Versions

As Colin Green, then Managing Director of Eurojet, noted, the performance goals of the EJ200 were conservative. The engine is normally run with a throttle in order to minimize maintenance and increase the service life. Since the engine core of the XG-40 is used, the engine can call up a much higher power than required. In the war setting , it develops a dry thrust of 69 kN and 95 kN with post-combustion. This increase in thrust is achieved by the compressor compressing more strongly. The air intake of the Eurofighter has already been dimensioned for this engine power. The contractual relic can easily be removed between two flights using a special notebook so that the XG-40 core can develop its full potential. The EJ200 can also provide a higher output in an emergency and then reaches 102 kN for a few seconds.

XG-40

Development model and ancestor of the Eurojets. Two engines were built, with a thrust-to-weight ratio of 10: 1 and 12: 1. Since the mass of the engine was around 900 kg, a thrust of 90 kN or 108 kN should have been achieved. The 108 kN are also given in the literature on the EJ200. The official information from Rolls-Royce on the thrust of the XG-40 is "over 50 kN" dry and "over 90 kN" with afterburner. With the above-mentioned performance goals of achieving 80% more dry thrust and 40% more afterburner thrust than the RB199, a dry thrust of 69 to 73 kN and an afterburner thrust of 92 to 102 kN can be calculated. This corresponds almost exactly to the EJ200 values ​​in the battle setting.

EJ200

EJ200

The engines of Tranche 1 aircraft are equipped with separate EMU and DECU. This series is known as the Mk 100. The engine is normally driven throttled. In this setting it provides a dry thrust of 59 kN and 89 kN with afterburning . The series version of tranche 2 with integrated DECMU is called Mk 101. Here, the thrust was increased to 60 kN dry and 90 kN wet in sustainability mode. When developing the DECMU, consideration was also given to being able to fly in a mixed configuration. This means that aircraft that were originally equipped with DECUs can be equipped with a DECMU with slight modifications (adaptation of the wiring harness between the airframe and the DECMU, including engine cabling).

EJ230

In development for future combat value increases . The target is about 72 kN dry thrust and about 103 kN afterburner thrust. A new fan with a higher compression ratio is to be installed for this increase in performance. Furthermore, the integration of the thrust vector control is envisaged.

Technical specifications

XG-40-1 XG-40-2 EJ200 Mk 100 EJ200 Mk 101 EJ230
First run 1986 > 1986 2003 2008 TBA
Dimensions ~ 900 kg 1037 kg ~ 1000 kg > 1000 kg
length 4 m
Fan diameter 0.74 m
compressor
Bypass ratio 0.4: 1
Compaction fan 3.9 (-) 4.2: 1 4.2: 1 (4.8: 1)
Compression compressor (6.6: 1) (-) (6: 1) 6.2: 1 6.2: 1
Total compression 26: 1 (-) 25: 1 26: 1 (30: 1)
combustion
Turbine inlet temperature 1800+ K 1755 K ~ 1800 K (-)
consumption Dry about 22 g / kNs and 48 g / kNs with afterburner
Mass flow rate possibly > 74 kg / s 73.9 kg / s ~ 76 kg / s TBA
Thrust nozzle
construction convergent adjustable convergent-divergent adjustable ditto with 3D control
Deflection speed N / A 110 ° / s
Max. Deflection angle N / A 23 °
Thrust development
Thrust without an afterburner 69 kN (72 kN) 59 kN 60 kN 72 kN
Thrust with afterburner 90-100 kN 108 kN 89 kN 90 kN 103 kN
Shear density, dry 160 kN / m² (167 kN / m²) 137 kN / m² 139 kN / m² 167 kN / m²
Thrust / weight, wet 10: 1 12: 1 9: 1 9: 1 10: 1

Users

7L-WG with ignited afterburners

So far the Eurojet is only used in the Eurofighter Typhoon and in the Bloodhound SSC. However, other platforms that have already been investigated are conceivable. These include warplanes:

  • Euro consortium roundel.svg Eurofighter Typhoon : first and main users. Allows the weapon system to maneuver continuously in supersonic conditions to increase effectiveness and survivability. Since the dry thrust of the EJ200 is only slightly below the afterburner thrust of the RB199 Mk104, with which the DA2 already reached Mach 2, only slightly slower speeds are possible without an afterburner.
  • Panavia consortium roundel.svg Panavia Tornado : The possibility of installation in the Tornado ADV was examined in 1991, and in 1992 for the Tornado IDS. Both examinations were positive. Since the dry thrust of the Eurojet exceeds the afterburner thrust of the Tornado IDS, high marching speeds would be possible to improve survivability against SAM positions and interceptors . The specific power surplus would also increase significantly.
  • Flag of Sweden.svg Saab 39 : Eurojet offers the EJ230 with thrust vector control for installation in the Gripen NG. Since the dry thrust of 72 kN is higher than that of the General Electric F414 G with 63 kN, higher supercruise speeds would be possible.
  • Flag of Turkey.svg TAI TFX : In January 2015 it was announced that Aselsan and Eurojet Turbo had signed a letter of intent according to which the TAI TFX's engine would be based on the Eurojet EJ200.

Training machines and light combat trainers:

  • Flag of Brazil.svg Flag of Italy.svg AMX International AMX : A modified version of the Eurojet without an afterburner and with 75 kN dry thrust was examined.
  • Flag of Europe.svg EADS Mako : This version was also examined for the Mako trainer, as the 75 kN thrust of the F414 would have been realizable without an afterburner in order to achieve the maximum speed of Mach 1.5. The armed version was to be equipped with a 90 kN version of the Eurojet.

Civil applications:

  • Bloodhound SSC : The Bloodhound Super Sonic Car is a rocket car designed to set a new land speed record. The vehicle has a rocket engine and a Eurojet EJ200, which will produce around 90 kN.

Web links

Commons : Eurojet EJ200  - collection of images, videos and audio files

Remarks

  1. ↑ a b A 8 = nozzle throat area, A 9 = nozzle outlet area

Individual evidence

  1. ^ Military propulsion technology. In: FLIGHT INTERNATIONAL. January 15, 1983, accessed May 17, 2014 .
  2. ^ Technology for Sustained Supersonic Cruise and Maneuver . In: AGARD FMP Symposium . October 1983.
  3. ↑ FRANZ ENZINGER, Messerschmitt-Bolkow-Blohm GmbH: Program review of European Fighter Aircraft , American Institute of Aeronautics and Astronautics Chapter doi: 10.2514 / 6.1988-2120 , 1988
  4. ↑ a b c Who will power EFA? In: FLIGHT INTERNATIONAL. April 14, 1984, accessed May 17, 2014 .
  5. ↑ a b c d e f Turbo-Union trio to power EFA? In: FLIGHT INTERNATIONAL. August 17, 1985, accessed May 17, 2014 .
  6. ↑ Rolls Readies Demonstrator Engine For European Fighter Aircraft . In: Aviation Week & Space Technology , McGraw-Hill, June 23, 1986. Retrieved July 5, 2007.  
  7. ↑ a b c Front-line power. In: FLIGHT INTERNATIONAL. April 12, 1986, accessed May 17, 2014 .
  8. ↑ a b c EFA engine alternatives. In: FLIGHT INTERNATIONAL. May 25, 1985, accessed May 17, 2014 .
  9. ^ Maintaining the Harrier Connection. In: FLIGHT INTERNATIONAL. June 1, 1985, accessed May 17, 2014 .
  10. ↑ a b c d XG.40 = EJ200 QED? (PDF) In: FLIGHT INTERNATIONAL. July 4, 1988, accessed May 17, 2014 .
  11. ↑ a b c d e Rolls-Royce: XG40-Rolls-Royce Advanced Fighter Engine Demonstrator . April 26, 1988.
  12. ↑ a b c d e Eurofighter Typhoon - Engines. (No longer available online.) In: typhoon.starstreak.net. May 13, 2013, archived from the original on July 31, 2010 ; accessed on May 13, 2013 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / typhoon.starstreak.net
  13. ↑ Will the UK develop its own stealth aircraft? In: FLIGHT INTERNATIONAL. November 8, 1995, accessed May 17, 2014 .
  14. ↑ Eurofighter engine company near formation. In: FLIGHT INTERNATIONAL. August 23, 1986, accessed May 17, 2014 .
  15. ↑ a b c Classification of aircraft engines. (PDF) In: Springer. 2009, accessed May 17, 2014 .
  16. ↑ a b c Power to Progress. In: FLIGHT INTERNATIONAL. April 16, 1991, accessed May 17, 2014 .
  17. ↑ a b c The power behind EFA. In: FLIGHT INTERNATIONAL. July 18, 1987, accessed May 17, 2014 .
  18. ↑ a b c Eurojet looks beyond EFA. In: FLIGHT INTERNATIONAL. July 1, 1989, accessed May 17, 2014 .
  19. ↑ a b Eurojet builds the first EFA engine. In: FLIGHT INTERNATIONAL. May 21, 1988, accessed May 17, 2014 .
  20. ↑ a b c d ITP: Thrust Vectoring Nozzle for Modern Military Aircraft. (PDF) (No longer available online.) In: NATO RTO. May 8, 2000, archived from the original on November 18, 2012 ; accessed on May 17, 2014 (English). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / ftp.rta.nato.int
  21. ↑ Eurofighter looks to use key X-31 technology. (PDF) In: Flight International. March 30, 1994, accessed April 21, 2014 .
  22. ↑ X-31 thrust-vectoring option for Eurofighter. (PDF) In: Flight International. April 23, 1994, accessed April 21, 2014 .
  23. ↑ Eurofighter rejects new control proposal. In: Flight International. January 25, 1995, accessed April 21, 2014 .
  24. ↑ a b Eurojet EJ200. In: Flight Revue. May 9, 2013, accessed May 17, 2014 .
  25. ↑ a b c Integrated Thrust Vectored Engine Control. (PDF) (No longer available online.) In: Motoren- und Turbinen-Union München GmbH. May 8, 2000, archived from the original on May 20, 2014 ; accessed on May 17, 2014 (English). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / ftp.rta.nato.int
  26. ↑ Partners poised to restart X-31 VECTOR. In: Flight International. February 18, 1998, accessed April 21, 2014 .
  27. ↑ DA4. In: airpower.at. May 9, 2013, accessed May 17, 2014 .
  28. ↑ US Navy options for X-31 follow-on. In: Flight International. April 18, 2000, accessed April 21, 2014 .
  29. ↑ X-31 to be used for thrust vectoring Eurofighter test. In: Flight International. November 14, 2000, accessed April 21, 2014 .
  30. ↑ US Navy seeks more funds for X-31. In: Flight International. August 14, 2001, accessed April 21, 2014 .
  31. ↑ Eurofighter Typhoon. In: Airforces Monthly Special. April 23, 2014, accessed May 30, 2014 .
  32. ↑ Baptism of fire passed - EJ200 engine parries in the rocket beam. (PDF) (No longer available online.) In: Universität Stuttgart. May 9, 2013, archived from the original on May 19, 2014 ; Retrieved May 17, 2014 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / ilaserver.ila.uni-stuttgart.de
  33. ↑ Thrust-Vectoring Upgrade for Typhoon Eurojet EJ200? In: Defense Update. February 9, 2011, accessed May 17, 2014 .
  34. ↑ a b c d Design of a new Fighter Engine - the dream in an engine man's life. (PDF) (No longer available online.) In: Schäffler, Lauer (MTU). May 11, 1998, archived from the original on May 20, 2014 ; accessed on May 17, 2014 (English). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / ftp.rta.nato.int
  35. ^ Eurofighter Typhoon - Flight systems. (No longer available online.) In: typhoon.starstreak.net. May 13, 2013, archived from the original on September 1, 2011 ; accessed on May 13, 2013 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / typhoon.starstreak.net
  36. ↑ a b c d e f g h Monitoring the EJ200 Engine. (PDF) In: MTU. September 19, 1995, accessed May 17, 2014 .
  37. ↑ Eurofighter for Switzerland | Drive - EJ200 . EADS, accessed April 13, 2010
  38. ↑ a b Superlative engines: Eurojet EJ200. (PDF) (No longer available online.) In: Cockpit. May 2010, archived from the original on March 4, 2016 ; accessed on November 10, 2017 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / www.cockpit.aero
  39. ↑ a b Eurofighter engines - development. In: airpower.at. May 9, 2013, accessed May 17, 2014 .
  40. ↑ a b EJ200. (No longer available online.) In: MTU Aero Engines. May 17, 2014, archived from the original on May 20, 2014 ; Retrieved May 17, 2014 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / www.mtu.de
  41. ↑ MTU Aero Engines: DESIGN IMPROVEMENTS OF THE EJ 200 HP COMPRESSOR. (PDF) (No longer available online.) In: Proceedings of ASME TURBO EXPO 2001: Land, Sea, and Air. June 4, 2001, archived from the original on May 20, 2014 ; accessed on May 17, 2014 (English). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / enginelease.aero
  42. ^ Federal Office for Defense Technology and Procurement: Engine EJ 200 , accessed on April 13, 2010
  43. ↑ a b c d EUROJET. (No longer available online.) In: EUROJET Turbo GmbH. May 17, 2014, archived from the original on May 29, 2014 ; accessed on May 17, 2014 (English). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / www.eurojet.de
  44. ↑ Heat of the Matter wants Kaveri Deliver? (No longer available online.) In: South Asia Defense & Strategic Review. September 26, 2008, archived from the original on March 17, 2014 ; accessed on May 17, 2014 (English). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / www.defstrat.com
  45. ^ The Mission Defines the Cycle: Turbojet, Turbofan and Variable Cycle Engines for High Speed ​​Propulsion. (PDF) (No longer available online.) In: NATO RTO-EN-AVT-185. September 2010, archived from the original on February 17, 2013 ; accessed on May 17, 2014 (English). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / ftp.rta.nato.int
  46. ↑ MTU Aero Engines: EJ200 - Digital Engine Control and Monitoring Unit (DECMU) , accessed on April 13, 2010.
  47. ↑ a b POSSIBILITIES THROUGH THE USE OF MODERN ELECTRONICS AND THE CHALLENGES THEREOF. (PDF) (No longer available online.) In: MTU Aero Engines GmbH. January 15, 2004, archived from the original on May 20, 2014 ; accessed on May 17, 2014 (English). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / www.mtu.de
  48. ↑ EJ.200 runs this year. In: FLIGHT INTERNATIONAL. September 17, 1988, accessed May 17, 2014 .
  49. ↑ a b Elodie Roux: Turbofan and turbojet engines: database handbook . 2007, ISBN 978-2-9529380-1-3 , pp. 163 ( preview on Google Books ).
  50. ↑ Eurofighter World: EUROFIGHTER REACHES THE REALMS OF THE F-22 , 3/2010.
  51. ↑ a b c d Eurojet aims EJ200 variant at thrust vectored Gripen. In: FLIGHT INTERNATIONAL. May 27, 1998, accessed May 17, 2014 .
  52. ^ Jane's All the World's Aircraft 1999-00
  53. ^ Germans consider EJ-200 for Tornado. (PDF) In: FLIGHT INTERNATIONAL. June 24, 1992, accessed May 17, 2014 .
  54. ↑ Jane's Information Group : Aselsan, Eurojet sign MoU ( Memento of the original from July 5, 2015 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (English), accessed January 25, 2015 @1@ 2Template: Webachiv / IABot / www.janes.com