Indian institute of space science and technology Thiruvananthapuram Done by : Priyanka Ojha , K.Raghava.
TRENT 1000-BOEING 787 ENGINE• The Trent 1000 engine is a three shaft high bypass ratio, axial flow, turbofan with Low Pressure, Intermediate Pressure and High Pressure Compressors driven by separate turbines through coaxial shafts.• Best engine for the Boeing 787 Dreamliner.• It is a new ultra-high-thrust variant of the Trent family and uses a three-shaft layout.• Least environmental impact• it is a bleedless design.
A significant architectural innovation• Higher propulsive efficiency through increased bypass ratio.• Higher engine thermal efficiency through increased overall pressure ratio and improved component efficiencies.• Improved thrust-to-weight ratio through the application of advanced materials.• Introduction of a novel dual-use electrical power generation system that doubled as the engine start system.
Intelligent innovation• The three-shaft architecture- the three-spool design affords intermediate pressure power off-take with demonstrated benefits in engine operability and fuel consumption.• The Trent 1000 is a bleedless engine to suit the requirements of the More Electric Boeing 787- This offers reductions in fuel burn and weight for the overall aircraft and enables increased levels of electrical energy to be transferred to the aircraft via the Intermediate Pressure (IP) spool power off-take. In addition, this unique three-shaft technology improves engine operability.• Incorporate the latest swept aero hollow-fan-blade technology evolved from the predecessor Trent 900 engine.• Incorporate surface coolers for compact and efficient rejection of VFSG and engine oil heat.
Intelligent innovation• Design the Trent 1000 with the latest computational fluid dynamics-enabled 3D aerodynamics for high efficiency and low noise.• improve component life the Trent 1000 features new technology- soluble core High Pressure (HP) turbine blades, new manufacturing methods produce more effective cooling for longer-life blades and improved fuel burn. Improved materials also increase lives of discs and shafts• Usage of Variable frequency starter generator(VFSG) which reduce fuel burn and noise on the 787.• The engine has 15% lower fuel burn than those of a decade ago, and delivers 40% lower emissions than required by current international legislation.
Interesting Facts• At take-off the Boeing 787 Dreamliner’s two Trent 1000s will deliver thrust of 150,000 lbf, which is equivalent to the power of 1,500 cars.• The engine sucks in 1.25 tons of air per second during take off (that’s about the volume of a racket ball court every second).• Air passing through the engine is squeezed to more than 700 lb per sq inch, which is 50 times normal air pressure.• The engine has about 30,000 individual components• The fuel in the engine combustion chamber burns at about 3632 deg F the sun’s surface is about 9941 deg F.• The force on a fan blade at take-off is about 100 tons. That is like hanging a freight train off each blade. The first generation of turbine blades had about 10 tons of force.• The blade tip travels at more than 900mph – faster than the speed of sound.• Each high pressure turbine blade produces more than 800 horsepower – the same as a NASCAR engine.
Stages• The LP and IP assemblies rotate independently in an anti-clockwise direction, the HP assembly rotates clockwise, when viewed from the rear of the engine. The Compressor and Turbine have the following features: Compressor Turbine LP – Single stage LP – 6 stage IP – 8 stage IP – single stage HP – 6 stage HP – single stage
Key parametersGeneral characteristics Type: Three-shaft high bypass ratio (11-10.8:1) turbofan engine Length: 4.738 m (186.5 in) Diameter: 2.85 m (112 in) (Fan) Dry weight: 5,765 kg (12,710 lb) Take-off thrust: 53000 - 75000 lbf Fan: 20 blades, 112" diameter(2.85 metres)Performance Maximum thrust: 53,000–75,000 lbf (240–330 kN) (flat-rated to ISA+15C) (Takeoff thrust) Overall pressure ratio: 52:1 (Top-of-Climb) Thrust-to-weight ratio: 6.189:1 (Trent 1000-J/-K at maximum thrust) Mass flow: 2,400 - 2,670 lb/s
Temperature Limits• Climatic Operating Envelope The engine may be used in ambient temperatures up to ISA +40°C.• Turbine Gas Temperature – Trimmed (°C) Maximum during ground starts and shutdown: 700 Maximum during in-flight relights: 900 Maximum for take-off (5 min. limit): 900 Maximum Continuous (unrestricted duration): 850 Maximum over-temperature (20 second limit): 920• Fuel temperature (°C) Minimum fuel temperature: -45 Maximum fuel temperature: 65• Oil temperature (°C) Range is -40 to 205
Pressure Limits Fuel pressure (kPa)Minimum absolute inlet pressure (measured at engine inlet):• Steady state conditions with engine running: 34.5 + vapour pressure• Transient conditions with engine running (2 seconds): 13.8 + vapour pressureMaximum pressure at inlet (measured at the pylon interface):• Steady state conditions with engine running: 483• Transient conditions with engine running (2 seconds): 966• Static after engine shut down: 1172
Maximum permissible rotor speedsRotor HP IP LPReference speeds, 100% rpm 13391 8937 2683Without SB 72-G319 Maximum for take-off 98.6% 100.8% 101.4% Maximum continuous 97.8% 99.5% 101.4%With SB 72-G319 Maximum for take-off 100.2% 103.5% 101.5% Maximum continuous 99.2% 100.8% 101.5% (Data makes allowance for instrumentation accuracies)
Fan system• Features: Low fan speed, life of engine blades, elliptical leading edge blades, low hub-to-tip ratio.• Moving a tonne of air per second, the fan produces over 85% of the engine’s thrust.• A 2.8 m (110 in) diameter swept-back fan, with a smaller diameter hub to help maximize airflow, This produces a higher bypass ratio without any increase in external diameter.• The biggest and most swept set of outlet guide vanes made from superplastic-formed/diffusion- bonded titanium; a forged titanium, lightweight and acoustically-treated rigid fan case.
Fan System• Fan blades rotate 3300 times per minute with a tip speed of 1730 km/hr• Heavy blades need more energy to move and therefore require more fuel.• Centripetal force is about 900 kN• Blades are about 10 kg in mass, 100 cm high and about 40 cm wide.• Made of Titanium alloy containing small amounts of Fe, O, V and Al.• Melting point-1604 -1660• Tensile strength-1000MPa.• The force on a Trent fan blade at take- off is almost 100 tons (1000 kN) Fully swept titanium fan
Trent 1000 - the world’s best fan• The proven swept fan design is the lightest in the industry and balances the requirement for low noise with high performance. It does this by combining lower rotational speed with advanced aerodynamic profiles. The low hub diameter enables a more compact design and even lower weight to be achieved.• The hollow titanium fan blade is the lightest weight solution due to its stiff girder structure
Fan Blade –Hollow titanium• First, at an atomic level, three sheets of titanium material, are fused. It has to be done in an ultra-clean production facility through a process of diffusion bonding.• Then the process of superplastic forming creates a hollow within the blade. Argon gas is used to inflate the titanium in a furnace operating at almost 1000°C. The two outer titanium panels are expanded, while the middle sheet is stretched into a zig-zag shape, creating the final hollow 3D aerodynamic shape of the blade and giving extraordinary rigidity to the structure• The hollow titanium fan blade coupled with linear friction welding made it possible to join the blade to the disk creating a single integrated structure, called a blisk or ‘bladed Rotor blisk disk’
Compressor -Intro• The compressor is made up of the fan and alternating stages of rotating blades and static vanes. The compression system of a Trent engine comprises the fan, eight intermediate pressure stages and six high pressure stages.• The primary purpose of the compressor is to increase the pressure of the air through the gas turbine core. It then delivers this compressed air to the combustion system.• The pressure rise is created as air flows through the stages of rotating blades and static vanes. The blades accelerate the air increasing its dynamic pressure, and then the vanes decelerate the air transferring kinetic energy into static pressure rises
Compressor-facts• At the start of an IPC the temperatures are around 1500C• The air leaves HPC at about 7000C• It compresses air at about 10,000 rpm• High strength, corrosion resistant to high temperatures, resistant to deformation and low density is required.• So we choose nickel based alloys.• Blades are made by forging and grinding.
Intermediate Pressure (IP) compressor • Benefits: Improved life, improved efficiency, improved robustness, optimised to reduce fuel consumption • Features: 3D-bladed aero compressor, IP power offtake, welded titanium drum, 8 stages of titanium blades, active Variable Stator Vane (VSV) schedule control • incorporates a de-icing system, in which 44 of the sector stators are pneumatically heated to prevent ice accumulation from freezing fog.
IP power offtake• Benefits: Lower fuel burn, significantly lower idle noise, reduced brake wear, improved operability• Features: Enabled by 3-shaft design, allows lower idle speed, lowers handling bleed requirement• Unlike its predecessors, the Trent 1000 power off-take is from the aft of the IP compressor rather than the usual front end of the HP compressor, allowing a greater stability margin and lower flight and ground idle thrust• The contra-rotating HP system delivers superior efficiency for the HP and IP turbine systems
High Pressure (HP) compressor• Benefits: Improved Foreign Object Damage (FOD) protection, high life system, improved robustness• Features: RR1000 material, inertia welded discs, titanium rotor 1 blades, improved blade root sealing• a new HP turbine casting design; as well as a higher temperature RR1000, R-R’s proprietary powder metallurgy alloy. This is used in the last two stages of the HP compressor drum and HP turbine disc.NOTE :- RR1000 is a powder nickel alloy introduced into theTrent 1000 to gain benefits in cycle operating temperature and component life.
Compressor stages Static pressure Total pressureincreasing Temperature Increasing pressure and temperature through compressors
Combustor-Intro• Air and fuel flow through the annular combustor. Air is diffused around the outside of the combustion chamber, slowing it down; the speed at which the air Fuel injector Igniter Secondary zone leaves the compressor would blow out the Nozzle guide vane flame were it to pass directly through. In the illustration, blue shows the combustion feed air from the HP compressor, and white through yellow to red, the hot combustion gases in the burning zones being cooled before entering the turbine system.• The gas temperatures within the combustor are above the melting point of the nickel alloy walls. Cooling air and thermal barrier Diffuser Primary zone Dilution zone coatings are therefore used to protect the walls and increase component lives. Dilution air is used to cool the gas stream before entering the turbines.
Combustor system• Benefits: Low risk, improved efficiency, low emissions, low noise.• Temperature in the combustion chamber can peak at 2100*C• The thermobarrier coating is around 250mm thick.• Cooler air from the compressor cools the walls of the combuster.• Materials used is Partially Yttria stabilized Zirconia whose melting point is in range of 2700-2850*C• Features: Phase 5 tiled combustor, single skin casing reduces leakage, 18 fuel spray nozzles, proven relight capability, anti-carboning design• The combustion chamber is designed for long life and low emissions.
Features of Combuster system• The use of heat-resistant ceramic tiles to line the combustor also reduces NOx emissions. The tiles mean you need less cooling air to cool the combustor. With less cooling air, which takes up space, the same amount of fuel burns in a larger volume, lowering peak temperature.• The "tiled combustor" also is designed to increase durability and reduce maintenance costs. The area exposed to high temperatures is lined with 2-by-6-inch, overlapping, heat- resistant tiles. This lining can grow and shrink with temperature cycles, shielding the metal rings of the combustor from the full effects of the heat and reducing cracking stress.
Turbine-Intro• The turbine is an assembly of discs with blades that are attached to the turbine shafts, nozzle guide IP turbine LP turbine vanes, casings and structures. HP turbine• Turbine blades convert the energy stored within the gas into kinetic energy. Like the compressor, the turbine comprises of a rotating disc with blades and static vanes, called nozzle guide vanes. The gas pressure and temperature both fall as it passes through the turbine.
Turbine -facts• Turbine blades rotate at about 10,000 rpm.• Work in temperatures up to 16000C• Each blades extracts about 560 kW of power from the hot gas.• The blade has to survive 5 million flying miles.• Turbine blades are made of a single crystal of nickel based super alloy to increase strength.• They are coated in an advanced ceramic material to insulate them from the extreme temperatures they are exposed to.
HP/IP turbine• Benefits: Low risk, improved efficiency, improved durability• Features: Active tip clearance control, RR1000 powder metallurgy disc, contra-rotating, 3D profiled end wall aerodynamics, soluble core HP blades, lower HP blade count (66), increased cooling effectiveness, anti blockage• A high pressure ratio along with contra-rotating the IP and HP spools improves efficiency
Turbine - Cooling Technology• HP turbine blades and HP Turbine blade nozzle guide vanes are designed with cooling passages and thermal HP turbine barrier coatings, to ensure blade cooling flows long life while operating at such high temperatures.• Cooling air is taken from the compressor and is fed around the combustor into the blades to cool the aerofoils. Blade cooling air
High pressure turbine blade• . This blade is grown as a single crystal of a Rolls-Royce alloy in a vacuum furnace. As it grows, it incorporates a complex series of air passages to cool the blade. Then it needs external cooling holes created by incredibly accurate laser drilling. And on top of all that is a thermal barrier coating that surpasses that used to make the tiles on the space shuttle.• The blade lives in the high-pressure turbine, where the gas temperature is at least 400 degrees above the melting point of the blade’s alloy. It sits in a disc that rotates at more than 10,000 rpm
Fan (LP compressor) IP compressor HP compressor IP turbine LP turbine Turbine LP IP HP Trent 1000 – three shaft configuration
Noise reduction• Rear view of Trent 1000 showing noise reducing chevrons, also called sawteeth.• Uses "crenellations" or "chevrons" on the trailing edge of the nacelles in order to reduce noise. These chevrons help to "premix" the core air and bypass air flows before they exit the aircraft.
NEW NACELLE FEATURES IMPROVE ON LEGACY DESIGNS The nacelle design maximizes composite and weight-saving materials to improve maintenance cost and fuel burn. Highlights include: • A single-piece inlet barrel construction for low noise. • Lightweight composite fan cowls. • A proven translating sleeve thrust reverser system that utilizes compact state-of-the-art 5,000 pounds per square inch (psi) hydraulic actuation. • Advanced titanium alloy exhaust system components. • A single-piece aft fairing. • Composite diagonal brace. • Advanced titanium alloy strut.*This view of the nacelle shows the inlet, fan cowls, thrust reverser, exhaust plug, and nozzle.
Variable frequency starter generator (VFSG) system• Replaces the heritage bleed air system used to feed the airplane’s environmental control system, thereby realizing direct weight savings through the elimination of relatively heavy bleed air components such as regulation valves, ducting, and coolers.• Eliminates the energy loss of the bleed air system pre-cooler.• Eliminates the throttling losses of bleed air provided from discrete engine compression stages.• Eliminates the single-purpose air turbine starters and their associated oil system and maintenance.• Simplifies the auxiliary power unit (APU) design to be a shaft power-only machine.
Pressure and temperature stations for Trent 1000
Performance curvesOn the Trent 1000 up to 30% of the power produced by the IP Turbine can betransmitted to the Electrical generators when operating at idle. This is a significantamount of the overall turbine power and will therefore have a significant effect onengine matching.During the following description the pressure ratio across the two compressors(P30/P24) and the level of power offtake (defined as a fraction of the total gasgenerator shaft power for a specified condition) will be kept constant. The shift ofthe compressor operating point is defined as the variation of the correctedinlet/outlet mass flow.HPC outlet non-dimensional mass flow =IPC inlet non-dimensional mass flow =
Typical HP compressor map with constant speed and constant efficiency iso-lines
Propulsive efficiency• Bypass ratio has increased thereby increasing the size of the engine. Up to a point, fan efficiency increases with size. The Trent 1000 engine has a bypass ratio of 10 and a fan diameter of 112 inches, compared to the predecessor Trent 700, which has diameter of 97 inches and a bypass ratio of 5. The Trent 1000 increases fuel consumption efficiency by 13 to 14 percent, compared to the Trent 700.• Reduce the fan pressure ratio, the ratio of the air pressure going out of the fan nozzle versus the air pressure coming into the fan. The lower fan pressure ratio, and the resulting lower exhaust velocity, improve propulsive efficiency and SFC
Thermal Efficiency• Thermal efficiency can increase by reducing aerodynamic losses in the engine components and increasing the overall pressure ratio (and resulting temperatures) in the core. The higher the pressure, the better the efficiency.• But since NOx emissions increase as pressures and temperatures rise, combustor technologies need to adjust. Rolls-Royce cites as critical technologies those that minimize the need for cooling air, improve cooling configurations for blades and improve materials and thermal barrier coatings.• Rolls-Royce has increased the overall compression ratio from the Trent 700 to the Trent 1000 from 33 to 50• The blisks end up increasing the overall efficiency of the engine by reducing the aerodynamic losses.