Presentation is loading. Please wait.

Presentation is loading. Please wait.

MAE 5350: Gas Turbines Lecture 1: Introduction and Overview Mechanical and Aerospace Engineering Department Florida Institute of Technology D. R. Kirk.

Similar presentations

Presentation on theme: "MAE 5350: Gas Turbines Lecture 1: Introduction and Overview Mechanical and Aerospace Engineering Department Florida Institute of Technology D. R. Kirk."— Presentation transcript:

1 MAE 5350: Gas Turbines Lecture 1: Introduction and Overview Mechanical and Aerospace Engineering Department Florida Institute of Technology D. R. Kirk

2 LECTURE OUTLINE Introduction –What is an air-breathing engine –Key questions Propulsion Options –Rocket Propulsion Overview and Basic Operation –Air-Breathing Propulsion Overview and Basic Operation –Momentum Exchange Physics Air-Breathing Engine Components –Nomenclature –Component Functionality –Engine Types Turbojet (+ afterburner), Turbofan, Turboprop, Ramjet, Scramjet Examples of Current Aircraft Engines Introduction to Propulsion Performance Parameters

3 ROCKET VS. AIR-BREATHING PROPULSION Take mass stored in a vehicle and throw it backwards → Use reaction force to propel vehicle –All fuel and oxidizer are carried onboard the vehicle Capture mass from environment and set that mass in motion backwards → Use reaction force to propel vehicle –Only fuel is carried onboard –Oxidizer (air) is ‘harvested’ continuously during flight

4 AIR-BREATHING PROPULSION Gas turbine engines power every modern aircraft and will for foreseeable future Gas turbines used for land-based power application, rocket engine turbo-pumps, marine applications, ground vehicles (tanks), etc. Many technical challenges to be addressed (Fuel Economy, Emissions, Noise) –Fluid mechanics, thermodynamics, combustion, controls, materials, etc. –One of most complicated, parts, extreme environment device on earth Enormous market: vast research and development $$ Development time of engine > development time of aircraft (5:3) Market is so competitive that engines are sold for a loss

5 DESIGN DRIVER: FUEL ECONOMY American Airlines Stock Price: Last 5 Years American Airlines CEO explains AA bankruptcy:

6 FUEL CONSUMPTION TREND JT8D JT9D PW4052 PW4084 Fuel Burn Year Future Turbofan U.S. airlines, hammered by soaring oil prices, will spend $5 billion more on fuel this year or even a greater sum, draining already thin cash reserves Airlines are among the industries hardest hit by high oil prices, which have jumped 38 percent in just 12 months. Airline stocks fell at the open of trading as a spike in crude-oil futures weighed on the sector NOTE: No Numbers

7 FUEL COST DRIVEN EXAMPLE With fuel now largest component of operating costs, air carriers are turning to fuel-saving measures that once seemed hardly worthwhile –Upswept wingtips to increase range and improve aerodynamics –Taxi to and from runway on one engine to save fuel –Does it make sense to actually fly slower? –Do you polish an airplane or paint it? –Airlines have new program to wash their aircraft/engines –Other cost saving measures 1 st and 2 nd bag check fee (and many others new fees…) Remove all pillows from MD-80’s






13 TRENDS TO BIGGER ENGINES 1958: Boeing 707, United States' first commercial jet airliner 1995: Boeing 777, FAA Certified PW : T=100,000 lbf,  ~ 6 Similar to PWJT4A: T=17,000 lbf,  ~ 1

14 VARIOUS NUMBER OF ENGINE CONFIGURATIONS 2 Engines 3 Engines 4 Engines 6 Engines



17 X-51


19 LARGEST GAS TURBINE ENGINE: SGT5-8000H Power 340 MW Extrapolated mass flow based on SGT100-SGT1000 series: 900 kg/s Average of SGT100-SGT1000, Assume  c : 15 Assumed  c (isentropic,  =1.35): 2 Assume 24 burners (consistent with SGT5-series) Combustor total CFM: 216,000 CFM per burner: 9,000 Full-scale, single-burner testing can be accomplished Trends: –If combustor inlet temperature is lower, CFM is lower –If combustor inlet pressure is higher, CFM is lower



22 WHY “AIR-BREATHING” PROPULSION Propulsion Goal: Create a Force to Propel a Vehicle (N.S.L) 2 ‘Choices’ for Propulsion 1.Take mass stored in a vehicle and throw it backwards → Use reaction force to propel vehicle Rocket Propulsion (MAE: 4262) All fuel and oxidizer are carried onboard vehicle 2.Capture mass from environment and set that mass in motion backwards → Use reaction force to propel vehicle Air-Breathing Propulsion (MAE: 4261) Only fuel is carried onboard Oxidizer (air) is ‘harvested’ continuously during flight Airplanes are very sensitive to environment in which they operate Rockets are highly insensitive to operational environment

23 HOW ALL ROCKET WORKS Rocket Propulsion: Produces thrust by ejecting stored matter Propellants combined in combustion chamber where chemically react to form high T&P gas Gases accelerated and ejected at high velocity through nozzle, imparting momentum to engine Thrust force is reaction experienced by structure due to ejection of high velocity matter Same phenomenon pushes garden hose backward as water flows from nozzle, gun recoil QUESTION: Could a rocket engine exert thrust while discharging into a vacuum (with not atmosphere to “push against”)? F Chemical Energy Thermal Energy Kinetic Energy

24 HOW AN AIRCRAFT ENGINE WORKS Flow through engine is conventionally called THRUST –Composed of net change in momentum of inlet and exit air Fluid that passes around engine is conventionally called DRAG Chemical Energy Thermal Energy Kinetic Energy

25 SUMMARY: ESTIMATES FOR THRUST Points to remember: –Mass flow for rocket is propellant carried onboard (fuel + oxidizer) –Mass for air-breathing engine is fuel carried onboard and air harvested from environment as airplane flies –Rockets usually require far higher thrust levels than airplanes –Airplanes usually fly for far greater durations than rockets Rocket Air-Breathing Engine


27 CROSS-SECTIONAL EXAMPLE: GE B Why does this engine look the way that it does? How does this engine push an airplane forward, i.e. how does it generate thrust? What are major components and design parameters? How can we characterize performance and compare with other engines? Compressor Combustor Turbine Fan Inlet Nozzle

28 EXAMPLE OF MILITARY ENGINE: TURBOJET OR LOW-BYPASS RATIO TURBOFAN Compressor CombustorTurbine Extreme Temperature Environment Afterburner

29 MAJOR GAS TURBINE ENGINE COMPONENTS 1.Inlet: –Continuously draw air into engine through inlet –Slows, or diffuses, to compressor 2.Compressor / Fan: –Compresses air –Generally two, or three, compressors in series –Raises stagnation temperature and pressure (enthalpy) of flow –Work is done on the air 3.Combustor: –Combustion or burning processes –Adds fuel to compressed air and burns it –Converts chemical to thermal energy –Process takes place at relatively constant pressure

30 MAJOR GAS TURBINE ENGINE COMPONENTS 4.Turbine: –Generally two or three turbines in series –Turbine powers, or drives, the compressor –Air is expanded through turbine (P & T ↓) –Work is done by the air on the blades –Use some of that work to drive compressor –Next: Expand in a nozzle –Convert thermal to kinetic energy (turbojet) –Burning may occur in duct downstream of turbine (afterburner) Expand through another turbine –Use this extracted work to drive a fan (turbofan) 5.Nozzle: –Flow is ejected back into the atmosphere, but with increased momentum –Raises velocity of exiting mass flow

31 2. COMPRESSORS: WHERE IN ENGINE? PW2000 Fan Compressor Purpose of fan is to increase efficiency of turbojet engine Much of air bypasses core of engine


33 TURBOFAN ENGINES Bypass Air Core Air Bypass Ratio, B,  : Ratio of by pass air flow rate to core flow rate Example: Bypass ratio of 6:1 means that air volume flowing through fan and bypassing core engine is six times air volume flowing through core

34 TRENDS TO BIGGER ENGINES 1958: Boeing 707, United States' first commercial jet airliner 1995: Boeing 777, FAA Certified PW : T=100,000 lbf,  ~ 6 Similar to PWJT4A: T=17,000 lbf,  ~ 1

35 HOW LARGE IS THE ENGINE? Engine is largest and most powerful turbofan built (11 ft 3 in (3.43 m) in diameter) In this case, 737 cabin is a mere 3% wider than 777 engine 11 ft 7 in (3.53 m) 11 ft 3 in (3.43 m)

36 2 SPOOL DEVICE: PW2000 High Pressure Compressor (  high ) Low Pressure Compressor (  low )

37 3. COMBUSTOR (BURNERS): LOCATION Military F Commercial PW4000 Combustor Afterburner

38 4. TURBINES: LOCATION High Pressure Compressor (  high ) Low Pressure Compressor (  low ) High and Low Pressure Turbines


40 5. NOZZLES: PW119 (F22 ENGINE)



43 COMMERCIAL AND MILITARY ENGINES (APPROX. SAME THRUST, APPROX. CORRECT RELATIVE SIZES) GE CFM56 for Boeing 737 T~30,000 lbf,  ~ 5 P&W 119 for F- 22, T~35,000 lbf,  ~ 0.3

44 THRUST VS. PROPULSIVE EFFICIENCY Conflict Important for both fighter and commercial aircraft T/W usually more important for military aircraft (maneuverability) Large mass flow means high W Fighter →  V Extremely important for commercial aircraft, much less so for fighter Efficiency critical for commercial Low  V, high mass flow

45 ENGINE STATION NUMBERING CONVENTION : Fan 2.5+: Compressor 3: Combustor 4: Turbine 0: Far Upstream 1: Inlet 5: Nozzle One of most important parameters is T T4 : Turbine Inlet Temperature Performance of gas turbine engine ↑ with increasing T T4 ↑

46 MAE 4261 REPRESENTATION OF AN ENGINE Compressor Combustor Turbine Inlet Nozzle Freestream



49 BOEING AT ROLLOUT Thrust Reverse on Landing

50 SIMPLE THRUST REVERSE MODEL: HOMEWORK #2 x y  Thrust Reverser Vane

51 TWO OTHER LAYOUTS UDF: Unducted Fan Concept GTF: Geared Turbofan

52 HIGH EFFICIENCY TURBINE ENGINE (HETE) FTT50FTA30 Ideal and non-ideal cycle analysis Combustor scaling with Da (  flow /  chem ), catalyst, porous metal Detailed component design (variable stators, electric generator, spin test rig, altitude test rig) 1 ft


54 EXAMPLES OF GAS TURBINE COMPONENTS Why film cooling? –Turbine inlet temperatures > melting temperatures of turbine blade materials Air provides a thin, cool, insulating blanket along external surface of turbine blade Example of Film-Cooled 1 st Turbine Blade Cooling Holes




58 NASA'S X-43A SCRAMJET BREAKS SPEED RECORD “NASA's X-43A research vehicle screamed into the record books again Tuesday, demonstrating an air-breathing engine can fly at nearly 10 times the speed of sound. Preliminary data from the scramjet-powered research vehicle show its revolutionary engine worked successfully at nearly Mach 9.8, or 7,000 mph, as it flew at about 110,000 feet.” “NASA's X-43A scramjet program successfully smashed its own world speed record for aircraft by flying at nearly 10 times the speed of sound. The flight proves its radical, air-breathing engine can function at speeds of nearly 12,000 kilometers per hour.” “Aviation history was made today as NASA successfully flew its experimental X- 43A research vehicle, a forerunner of craft that could well offer alternate access to space in the future.”

59 AIRCRAFT ENGINE BASICS All aircraft engines are HEAT ENGINES –Utilize thermal energy derived from combustion of fossil fuels to produce mechanical energy in form of kinetic energy of an exhaust jet –Momentum excess of exhaust jet over incoming airflow produces thrust Thrust = Force = Time Rate Change of Momentum In studying these devices we will employ two types of modeling 1.Fluid Mechanic Relate changes in pressure, temperature and velocity of air to physical characteristics of engine 2.Thermodynamic (Cycle Analysis) Thermal → mechanical energy from thermal is studied using thermodynamics Study change in thermodynamic state of air as passed through engine Geometry of engine NOT important, but rather processes are important


61 ENGINE SURGE EVENT Surge: Violent reverse flow situation: Burning combustion gases driven upstream through compressor and out of engine Usually accompanied by downstream fire Engine must maintain structural integrity and be able to be shut down


63 Supplemental Slides: Aircraft Engine Manufacturers

64 AIRCRAFT ENGINE MANUFACTURERS 3 Major Aircraft Manufacturers in World Today (Commercial and Military) 1.Pratt and Whitney (USA) 2.General Electric (USA) 3.Rolls Royce (GB) Applications for Gas Turbines –Commercial and Military Aircraft Engines, Helicopters –Chemical Rocket Engines –Industrial (marine turbines, yachts, assault ships, etc.) –Power Plants Interesting Note: –Companies sell product at a $$ loss –Profit is made many years later on refurbishment, spare parts, maintenance

65 COMMERCIAL AIRCRAFT ENGINES: JT8D Engine Models JT8D-7/7A JT8D-9/9A JT8D-15/15A JT8D-17/17A JT8D-17R/17AR JT8D-217C JT8D-219 Airplanes Powered Boeing 727 Boeing /-200 McDonnell Douglas DC-9 Boeing MD-80

66 COMMERCIAL AIRCRAFT ENGINES: JT8D P&W introduced JT8D to commercial aviation in February 1964 (Boeing's ) 8 models of JT8D standard engine family cover thrust range from 14,000 to 17,400 pounds and power 727, 737, and DC-9 aircraft More than 11,800 JT8D standard engines produced, over one-half billion hours of service operation. New Program emphasis is on compliance with noise regulations For -200 models, a new low-emissions combustion system, or E-Kit, has been FAR 25 certified. Reduces NOx by 25 percent, unburned hydrocarbons by 99 percent and smoke by 52 percent relative to current models The -200 is also the exclusive power for the Super 27 re-engining program, in which Pratt & Whitney, in cooperation with Goodrich Aerostructures, is offering 727 operators a solution to achieve Stage 3/Chapter 3 compliance with improved performance. Involves replacing two outboard engines with new JT8D-217C/219 models and adding noise suppression equipment. The Super 27 can increase range up to 1,200 nautical miles and permits carrying up to 30 more passengers or up to 10,000 pounds in additional cargo. Engine Characteristics –Fan tip diameter: in –Length, flange to flange: in –Takeoff thrust: 14, ,700 lb –Bypass ratio: –Overall pressure ratio: –Fan pressure ratio:


68 P&W 94 inch Engine Models –PW4052 –PW4056 –PW4060 –PW4062 –PW4062A –PW4152 –PW4156A –PW4156 –PW4158 –PW4460 –PW4462 Airplanes Powered –Boeing –Boeing /-300 –Boeing MD-11 –Airbus A –Airbus A P&W 100 inch Engine Models –PW4164 –PW4168 –PW4168A Airplanes Powered –Airbus A –Airbus A P&W 112 inch Engine Models –PW4074 –PW4077 –PW4077D –PW4084 –PW4084D –PW4090 –PW4098 Airplanes Powered –Boeing /-300

69 P&W 4000 SERIES: 94 INCH FAN Pratt & Whitney's PW inch fan model is the first in a family of high-thrust aircraft engines Certified thrust ranging from 52,000 to 62,000 pounds, it powers the Airbus A and A aircraft and Boeing , /300 and MD-11 aircraft. For twin-engine aircraft, the PW4000 is approved for 180-minute ETOPS (Extended-range Twin-engine Operations). Entered service in Advanced, service-proven technologies, such as single-crystal superalloy materials and its Full-Authority Digital Electronic Control (FADEC) for superior fuel economy and reliability. The engine's attractiveness is further enhanced by excellent performance retention, long on-wing times and low maintenance costs. Meets all current and anticipated emissions and noise regulations with margin. For a further reduction in emissions, especially NOx, TALON (Technology for Advanced Low NOx) combustor technology is now available as an option. Derived from the 112- inch fan model, TALON has segmented, replaceable liner panels for maintainability and air blast fuel nozzles for excellent fuel atomization and mixing Engine Characteristics –Fan tip diameter: 94 in –Length, flange to flange: in –Takeoff thrust: 52, ,000 lb –Flat rated temperature: 86 or 92° F –Bypass ratio: 4.8 to 5.1 –Overall pressure ratio: 27.5 to 32.3 –Fan pressure ratio:

70 P&W 4000 SERIES: 100 INCH FAN PW inch fan engine is first derivative model in PW4000 family. Developed specifically for Airbus Industrie's A330 twinjet, certified from 64,500 to 68,600 pounds of thrust. PW4168 features the industry's lightest weight and most advanced nacelle. Incorporates a number of service-proven technologies in materials, aerodynamics and controls to enhance performance, reliability and durability. The engine was the first in aviation history to qualify for ETOPS (Extended-range Twin-engine Operations) prior to entering service. It is now approved for 180-minute ETOPS. Meets all present and anticipated noise and exhaust emissions regulations. PW inch engines have accumulated more than three million hours of revenue service and are the leading engine on the A330 Engine Characteristics –Fan tip diameter: 100 in –Length, flange to flange: in –Takeoff thrust: 64, ,600 lb –Bypass ratio: 5.1 –Overall pressure ratio: 32.0 –Fan pressure ratio: 1.75

71 P&W 4000 SERIES: 112 INCH FAN PW inch fan engine is second derivative model in PW4000 engine family. The PW4084, certified at 86,760 pounds thrust, was the launch engine for Boeing's 777 super twinjet. It entered service in June 1995 with United Airlines, already qualified for 180-minute ETOPS (Extended-range Twin-engine Operations). First engine to operate with approval for 207-minute ETOPS. The PW4090, certified at 91,790 pounds of thrust, entered service on the Boeing ER airplane in March The most recent model, the PW4098, was certified in July The PW4098, at 99,040 pounds of thrust, is available for ER and models. For transportability, the engine can be shipped in a 747F as a complete engine. Also, the fan case is easily separated from the engine's core for split shipment without disturbing the bearing compartments. Engine Characteristics –Fan tip diameter: 112 in –Length, flange to flange: in –Takeoff thrust: 74, ,000 lb –Bypass ratio: 5.8 to 6.4 –Overall pressure ratio: –Fan pressure ratio:

72 GE 90 FAMILY: MOST POWERFUL ENGINES IN WORLD GE Aircraft Engines was specified by Boeing to develop a 115,000 pound-thrust GE90 derivative engine for all longer-range LR and -300ER derivatives. Derivative engine represents the successful culmination of GE's strategy in the early 1990s to build a new centerline engine for the Boeing 777 family. Since its initial testing, the GE90-115B has set numerous aviation records including reaching a sustained record 122,965 lbs. of thrust during initial ground testing at GE's outdoor test facility

73 P&W / G.E. GP7000 FAMILY

74 WORLD’S LARGEST PASSENGER AIRLINER: A A Wing span 79.8m (261ft 10in), length 73m (239ft 6in). Height 24,1 m (79ft 1in)

75 P&W / G.E. GP7000 DETAILS AND SPECIFICATIONS Joint effort between Pratt & Whitney and General Electric GP7000 is derived from some of the most successful widebody engine programs in aviation history (GE90 and PW4000 families) –Industry leading ETOPS reliability from service entry –Over 250 million hours of performance –Built on GE90 core and PW4000 low spool, but with many new technologies –Best of GE Aircraft Engines and Pratt & Whitney technologies Two-spool simplicity for reliability and maintainability Best payload capability, performance and performance retention. Quietest and lowest emissions in its class. Engine Characteristics –Fan tip diameter: 116 in –Length, flange to flange: 187 in –Takeoff thrust: 70,000 lb –Flat rated temperature: 86° F –Bypass ratio: 8.7

76 FUEL CONSUMPTION TREND JT8D JT9D PW4052 PW4084 Fuel Burn Year Future Turbofan U.S. airlines, hammered by soaring oil prices, will spend $5 billion more on fuel this year or even a greater sum, draining already thin cash reserves Airlines are among the industries hardest hit by high oil prices, which have jumped 38 percent in just 12 months. Airline stocks fell at the open of trading Tuesday as a spike in crude-oil futures weighed on the sector NOTE: No Numbers


78 P&W F100 DETAILS AND SPECIFICATIONS Powers all current F-15 figher aircraft and F-16 fighter aircraft in 21 countries. More than 6,900 engines produced and over 16 million flight hours. F100-PW-229 is the most mature Increased Performance Engine (IPE) available and is the engine of choice for air forces worldwide. It is the only IPE engine operationally matured in both the F-15E and F-16 Block 52 aircraft. Using technology developed from the F119 and F135 engine programs for the F/A-22 Raptor and F-35 Joint Strike Fighter, the current production PW-229 incorporates modern turbine materials, cooling management techniques, compressor aerodynamics and electronic controls. In addition to offering the most technologically advanced IPE available, Pratt & Whitney offers a comprehensive range of maintenance management programs and engine overhaul services to meet all customer requirements. These programs provide customers with low-cost maintenance solutions and superb operational readiness. Engine Characteristics –Thrust: 23, ,160 lb –Weight: 3,740 lb –Length: 191 in –Inlet Diameter: 34.8 in –Maximum Diameter: 46.5 in –Bypass Ratio: 0.36 –Overall Pressure Ratio: 32 to 1


80 P&W F119 DETAILS AND SPECIFICATIONS P&W F119 turbofan engine. In the 35,000 pound thrust class, engine is a dual spool, counter-rotating turbofan that enables aircraft operation at supersonic speeds for extended periods. F119 is equipped with a number of advanced technologies. Three-stage fan has shroudless titanium fan blades and is powered by a single-stage low-pressure turbine. The engine's core has an aerodynamically efficient six-stage compressor driven by a single-stage high- pressure turbine featuring the next generation of single-crystal superalloy blades with improved cooling management. Robust, but compact, high-pressure compressor features integrally bladed rotor disks for improved durability and three-dimensionally designed airfoils. Convergent/divergent nozzle vectors thrust 20 degrees either up or down. Nozzle position management is automatically controlled by the full-authority digital electronic control (FADEC), which controls hundreds of other engine and aircraft operating parameters. F/A-22 full operational capability is expected in Engine Characteristics –Type: Twin-Spool, Augmented Turbofan –Thrust: 35,000 Pound Thrust Class –Engine control: Full-Authority Digital Electronic Control –Compression system: Twin Spool/Counter Rotating/Axial Flow/Low Aspect Ratio –Combustor: Annular –Turbine: Axial Flow/Counter-Rotating –Nozzle: Two Dimensional Vectoring Convergent/Divergent


82 A GOOD PLACE FOR MARKET NEWS Singapore Airlines places US$7.35 bln Boeing order August 25, :13:57 (ET) SINGAPORE, Aug 25 (Reuters) - Singapore Airlines Ltd. ((SIAL.SI)), the world's second-largest airline by market value, said on Wednesday it had ordered 31 Boeing Co (BA,Trade) long-range ERs worth about US$7.35 billion in a fleet renewal programme.BATrade The aircraft will be powered by engines from General Electric Co (GE,Trade), Asia's most profitable airline said.GETrade The national carrier had asked airframe manufacturers Boeing Co (BA,Trade) and Airbus SAS ((EAD.DE))((EAD.PA)) to bid for new plane orders it may place later this year.BATrade Boeing, the No. 2 maker of jetliners, is in a dogfight for market share with No. 1 Airbus. The planes will cover the medium-haul and regional needs of the 57 percent government-owned airline over the coming years.


84 SIEMENS POWER GENERATION: ORLANDO The SGT-300 Industrial Gas Turbine for Power Generation (ISO) 7.90MW(e) The SGT-300 is available with a Dry Low Emissions (DLE) combustion system, providing extremely low NOx levels with gas and liquid fuels and a full dual fuel capability. The SGT-300 design is uniquely simple, employing a single twin bearing rotor with heavy duty casings. This allows full site maintenance to be carried out. The generator set package is very compact, providing a small footprint and a high power-to-weight ratio. The single-shaft configuration provides excellent load acceptance and rejection characteristics, allowing robust and reliable operation in all applications. SGT-800 Industrial Gas Turbine – 45MW The SGT-800 combines reliable, robust industrial design with the high efficiency and low emission levels of the latest turbine technology. It allows you to implement rapid, low-cost solutions for combined heat and power production. Moreover, it's environmentally sound, compact and easy to install. Designed for continuous, heavy-duty operation, the SGT-800 is the obvious choice where reliability, environmental concerns and low life-cycle costs are key factors. In combined cycle installations, this turbine affords very competitive life-cycle costs. It also offers high efficiency in simple cycle operation. And its powerful heat production capability in cogeneration installations makes it the ideal choice for the process industry.

Download ppt "MAE 5350: Gas Turbines Lecture 1: Introduction and Overview Mechanical and Aerospace Engineering Department Florida Institute of Technology D. R. Kirk."

Similar presentations

Ads by Google