Thanks to USAFA and USAF Test Pilot School Propulsion 1 Dr. Ken Van Treuren Department of Engineering Baylor University EGR Analysis and Design of Propulsion Systems

Thanks to USAFA and USAF Test Pilot School Propulsion 2 BEGINNINGS Date: 17 December 1903 Location: Kitty Hawk, North Carolina

Thanks to USAFA and USAF Test Pilot School Propulsion 3 Faster -- Higher -- Farther

Thanks to USAFA and USAF Test Pilot School Propulsion 4 Prevailing Thoughts “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

Thanks to USAFA and USAF Test Pilot School Propulsion 5 Sir Frank Whittle (1941) Gloster E28/29 Experimental Aircraft W.1

Thanks to USAFA and USAF Test Pilot School Propulsion 6 Hans von Ohain (1937) HeS 3B He 178

Thanks to USAFA and USAF Test Pilot School Propulsion ’s Jumo 004 World’s 1 st mass produced turbojet ME

Thanks to USAFA and USAF Test Pilot School Propulsion ’s F-4E J-79

Thanks to USAFA and USAF Test Pilot School Propulsion ’s TF-39 C5A

Thanks to USAFA and USAF Test Pilot School Propulsion ’s F100 F-15

Thanks to USAFA and USAF Test Pilot School Propulsion ’s-1990’s F-22 F-119

Thanks to USAFA and USAF Test Pilot School Propulsion ’s ’s JSF YF-120, with axisymmetric vectoring nozzle

Thanks to USAFA and USAF Test Pilot School Propulsion 13 Dark Star, LO High Endurance UAV Predator, Medium Altitude Endurance UAV Global Hawk, High-Alt Long Endurance Aerial Recon UAV X-43, Hypersonic Research Vehicle Uninhabited Combat Air Vehicle (UCAV)

Thanks to USAFA and USAF Test Pilot School Propulsion 14 Aviation Week & Space Technology, April 1, 2002, p28 Boeing Sonic Cruiser Aviation Week & Space Technology, April 15, 2002, p69 Aviation Week & Space Technology, May 6, 2002, p28 B-X Supersonic “Quiet” Bomber M400 Skycar Mechanical Engineering, May 2001, p96 Airbus A Space Launch Initiative (SLI) Aerospace Engineering, March 2001, p7

Thanks to USAFA and USAF Test Pilot School Propulsion 15

Thanks to USAFA and USAF Test Pilot School Propulsion 16 Basic Turbine Engine Components Compressor Combustor TurbineNozzle

Thanks to USAFA and USAF Test Pilot School Propulsion 17 J-79 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 Turbojet

Thanks to USAFA and USAF Test Pilot School Propulsion 18 Turbojet - Applications Harpoon (TJ+solid fuel booster) Concorde F-4 SR-71

Thanks to USAFA and USAF Test Pilot School Propulsion 19 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

Thanks to USAFA and USAF Test Pilot School Propulsion 20 Tomahawk Cruise Missile Low Bypass Ratio Turbofan - Applications UCAV JSF YF-22

Thanks to USAFA and USAF Test Pilot School Propulsion 21 High Bypass Ratio Turbofan GE-90

Thanks to USAFA and USAF Test Pilot School Propulsion 22 High Bypass Ratio Turbofan - Applications 777 A-10 KC-10 C-5A

Thanks to USAFA and USAF Test Pilot School Propulsion 23 Turboprop/Turboshaft 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 T-800

Thanks to USAFA and USAF Test Pilot School Propulsion 24 Turboprop/Turboshaft - Applications V-22 Saab 2000 C-130 RAH-66 Comanche

Thanks to USAFA and USAF Test Pilot School Propulsion 25 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 Ramjet/SCRAMjet Liquid Propellant Ramjet Solid Fuel Ramrocket at Launch - Rocket Mode SCRAMjet (StrutJet)

Thanks to USAFA and USAF Test Pilot School Propulsion 26 D-21 Drone Hyper -X Fasthawk Ramjet/SCRAMjet - Applications Bomarc Hypersoar

Thanks to USAFA and USAF Test Pilot School Propulsion 27 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, D inlet Nozzle Drag, D nozzle Relationships T = F - Dinlet - Dnozzle = F(1-  inlet -  nozzle ) TSFC = S/ (1-  inlet -  nozzle )

Thanks to USAFA and USAF Test Pilot School Propulsion 28 Principles of Jet Propulsion - THRUST Direction of Movement Escaping Air Opposite force causes the balloon to move Forces removed by opening the stem

Thanks to USAFA and USAF Test Pilot School Propulsion 29 F = ma gcgc  F = 1 dM g c dt 1 d(mV) g c dt = Note: Momentum = M = mV Force = mass x acceleration F n = m gcgc (V j - V a ) + A j (P j - P atm ) Net thrust = change in momentum + pressure force at exit Principles of Jet Propulsion - THRUST Thrust is therefore produced when air exits the engine faster than when it entered.

Thanks to USAFA and USAF Test Pilot School Propulsion 30 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

Thanks to USAFA and USAF Test Pilot School Propulsion Inlet Low-pressure compressor High- pressure compr Combustor HPTHPT LPTLPT Nozzle Gas generator HPT = High-pressure turbine LPT = Low-pressure turbine Basic Turbine Engine Components - Schematic & Numbering

Thanks to USAFA and USAF Test Pilot School Propulsion Static Pressure (psia) Static Temperature (R) Static Temperature and Pressure Variations Through Engine

Thanks to USAFA and USAF Test Pilot School Propulsion 33 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 F  m gcgc (V e - V i )

Thanks to USAFA and USAF Test Pilot School Propulsion 34 Engine Performance Characteristics

Thanks to USAFA and USAF Test Pilot School Propulsion 35 Engine Performance Characteristics