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Dr. Ken Van Treuren Department of Engineering Baylor University. EGR 4347 - Analysis and Design of Propulsion Systems. Date: 17 December 1903 Location: Kitty Hawk, North Carolina. BEGINNINGS. Faster -- Higher -- Farther.
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Dr. Ken Van Treuren Department of Engineering Baylor University EGR 4347 - Analysis and Design of Propulsion Systems
Date: 17 December 1903 Location: Kitty Hawk, North Carolina BEGINNINGS
“In its present state, and even considering the improvements possible in adopting the higher temperatures proposed for the immediate future, the gas turbine could hardly be considered a feasible application of airplanes, mainly because of the difficulty in complying with the stringent weight requirements imposed by aeronautics.” National Academy of Sciences - Late 1930’s Prevailing Thoughts
Sir Frank Whittle (1941) W.1 Gloster E28/29 Experimental Aircraft
Hans von Ohain (1937) HeS 3B He 178
1940’s Jumo 004 World’s 1st mass produced turbojet http://www.soton.ac.uk/~aeroastr/4projects/Genesis/Level2/Engines/Jumo4.htm ME 262 http://www.iag.net/~emccann/models/me262rec.htm
1950’s J-79 http://www.seattleu.edu/~jmatt/pictures/J79.gif F-4E http://www.wpafb.af.mil/museum/research/fighter/f4e-18.jpg
1960’s TF-39 http://www.seattleu.edu/~jmatt/pictures/TF39.gif C5A http://www.primenet.com/~gbe/Midway/C5A_Galaxy.htm
1970’s F100 F-15 http://www.wpafb.af.mil/museum/modern_flight/mf21b.htm
1980’s-1990’s F-119 F-22
1990’s - 2000’s YF-120, with axisymmetric vectoring nozzle http://www.aeroworldnet.com/fth15.htm JSF
2002+ Uninhabited Combat Air Vehicle (UCAV) X-43, Hypersonic Research Vehicle http://popularmechanics.com/popmech/sci/tech/9709TUMIAM.html Predator, Medium Altitude Endurance UAV Dark Star, LO High Endurance UAV Global Hawk, High-Alt Long Endurance Aerial Recon UAV http://www.fas.org/irp/agency/daro/uav95/gifs/predcomp.gif http://www.fas.org/irp/program/collect/darkstar.htm http://defenselink.dtic.mil/photos/Feb1997/970220-D-0000G-001.html
2002+ Space Launch Initiative (SLI) Airbus A-380 Aviation Week & Space Technology, April 1, 2002, p28 Aerospace Engineering, March 2001, p7 Boeing Sonic Cruiser Aviation Week & Space Technology, April 15, 2002, p69 B-X Supersonic “Quiet” Bomber M400 Skycar Mechanical Engineering, May 2001, p96 Aviation Week & Space Technology, May 6, 2002, p28
Basic Turbine Engine Components Compressor Turbine Nozzle Combustor
Turbojet • Advantages • Few Moving Parts • Large Operating Envelope • Static Thrust • Small Frontal Area • Disadvantages • Large Number of Parts • Expensive • Low Thrust at Low Mach • High noise • High TSFC • Application - broad range • Small Mass to High Velocity J-79
Turbojet - Applications SR-71 Harpoon (TJ+solid fuel booster) F-4 Concorde
Low Bypass Ratio Turbofan • Advantages • Few Moving Parts • Large Operating Envelope • More Static Thrust • Better Subsonic TSFC • FOD protection of HPC • Large Afterburner Possible • Low Noise • Disadvantages • Large Number of Parts • Expensive • Medium Frontal Area • Engine Response • Air Start • Application - medium mass to medium velocity F100
Low Bypass Ratio Turbofan - Applications YF-22 Tomahawk Cruise Missile UCAV JSF
High Bypass Ratio Turbofan - Applications A-10 KC-10 C-5A 777
Turboprop/Turboshaft T-800 • Advantages • Few Moving Parts • Large Operating Envelope • Best Static Thrust • Best Low Subsonic TSFC • Constant RPM Possible • Low Noise • Propeller Reverse • Disadvantages • Large Number of Parts • Expensive • Complex Gearbox • Large Frontal Area • Propeller Governor • Application - Low Mach (Large mass to low velocity) T-56
Turboprop/Turboshaft - Applications Saab 2000 C-130 V-22 RAH-66 Comanche
Ramjet/SCRAMjet • Advantages • No moving parts • Simple • Inexpensive • Small frontal area • Disadvantages • No accessory drive • Optimized for design condition • No static thrust • Application High Mach • Bomarc missle • Future missles Liquid Propellant Ramjet Solid Fuel Ramrocket at Launch - Rocket Mode SCRAMjet (StrutJet)
Ramjet/SCRAMjet - Applications Fasthawk Hyper -X Bomarc D-21 Drone Hypersoar
Principles of Jet Propulsion - Engine Performance • Installed Performance • Thrust, T • Thrust Specific Fuel Consumption, • Uninstalled Performance • Thrust, F • Thrust Specific Fuel Consumption, • Installation losses • Inlet Drag, Dinlet • Nozzle Drag, Dnozzle • Relationships • T = F - Dinlet - Dnozzle = F(1-finlet - fnozzle) • TSFC = S/ (1-finlet - fnozzle)
Opposite force causes the balloon to move Forces removed by opening the stem Principles of Jet Propulsion - THRUST Direction of Movement Escaping Air
ma 1 dM 1 d(mV) F = gc gc dt gc dt m Fn = (Vj - Va) + Aj (Pj - Patm) gc Principles of Jet Propulsion - THRUST S F = = Note: Momentum = M = mV Force = mass x acceleration Net thrust = change in momentum + pressure force at exit Thrust is therefore produced when air exits the engine faster than when it entered.
Principles of Jet Propulsion - THRUST • From a thermodynamic perspective, the engine’s job is to convert chemical • energy of the fuel into kinetic energy of the air passing through the engine. • The following engine components enable this energy conversion and determine • the efficiency at which this conversion takes place: • INLET - Converts kinetic energy of entering air into a pressure rise by decelerating the flow • COMPRESSOR - Increases air pressure to increase combustion cycle efficiency • COMBUSTOR - Add chemical energy to the air to provide power to the turbine and to produce desired thrust • TURBINE - Extracts energy from the hot gases to drive the compressor and aircraft accessories • EXHAUST DUCT AND NOZZLE - Collects, straightens, and accelerates the air
High- pressure compr H P T L P T Low-pressure compressor Inlet Combustor Nozzle 0 1 2.5 3 4 4.5 5 8 Basic Turbine Engine Components - Schematic & Numbering Gas generator HPT = High-pressure turbine LPT = Low-pressure turbine
350 300 250 200 150 100 50 0 Static Temperature and PressureVariations Through Engine Static Pressure (psia) Static Temperature (R)
F (Ve - Vi) gc m Engine Types Turbojet - large velocity change Low Bypass Ratio Turbofan - large velocity change & increased mass flow High Bypass Ratio Turbofan - very large mass flow & small velocity increases Turboprop - energy extracted by a low pressure turbine drives a gear box which runs a prop. Large mass flow, very small velocity change through prop Turboshaft (similar to turboprop) - runs a rotor or power producing shaft Ramjet - M>1 applications, large mass flow & small velocity increase SCRAMjet - M>5 applications, very large mass flow & small velocity increase