2018/4/27 国上活大坐 Overview of Lectures 国上清大学 0.Overview 14/15 Performance(a,b) 16.Aircraft certification 2.Overall configuration 17.Aviation economics weight estimation 18.System integration and eight estimation configuration management Aircraft Design Fuselage design 19.Multidisciplinary design 6/7/8 Aerodynamic design(a,b,c) ootimization (飞行器设计) .hat and ing 20.Military aircraft design-overview 21.Environmental issues 10.Landing gear and Aircraft systems 22.Desian skills 11.Power plant Wenbin Song 12.Stability and control School of Aeronautics and Astronautics 13.Loads,materials and structures oorornenin ong Outline 国上活大峰 Propulsion System Speed Limits 园上活道大整 ·Types of propulsion INCREASING SFC Principles of air breathing engines (TYPICAL APPLICATIONS Engine characteristics Engine parameters >ROCKET Engine efficiency 等SCRAMJET 。 Engine performance ·Engine installation >RA 。Inlet and nozzle ·Fuel System AFTERIURNING LOW-BYPASS-RATIO TURBOFAN MDO design of engine systems DRY LOW-BYPASS-RATIO TURROEAYO work efficiently up to 乞HIGH-BYPASS-RATIO TURBOFAS Mach 16 Msch=0.7 FISTON-FROP 1 DSG MACH NUMBE载 Basic Principles of Powerplants 国上清大学 Basic Principles of Powerplants thrust ideal propulsion efficiency 园上海发大坐 The thrust generated by an engine is the rate of change of Ignoring the fuel rate mg and assume full expansion momentum imposed upon propelling medium P=Po,the thrust can be simplified as T=( T-阳-&r--o) Thrust power-the rate of useful work done where m is mass of propelling medium andis velocity of g=7严%=-6% propelling medium Power expended-time derivative of work For air breathing engines For rocket engines T=m(y-%)+mey+(P-p%)4 m T=Vjat m is mass flow rate of air, A近---因 m is rate of fuel usage, is the rate of burning of propellan V and vo are jet velocity and aireraft speed, The propulsion efficiency V is jet velocity speed 2 static pressure A is the exhaust area e-AE,/。+1 1
2018/4/27 1 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Wenbin Song School of Aeronautics and Astronautics Shanghai Jiao Tong University swb@sjtu.edu.cn Aircraft Design （飞行器设计） © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Overview of Lectures 0. Overview 1. Introduction 2. Overall configuration 3. Preliminary weight estimation 4. Refined weight estimation 5. Fuselage design 6/7/8 Aerodynamic design(a, b, c) 9. Thrust/Weight ratio and wing loading 10.Landing gear and Aircraft systems 11.Power plant 12.Stability and control 13.Loads, materials and structures 14/15 Performance(a, b) 16.Aircraft certification 17.Aviation economics 18.System integration and configuration management 19.Multidisciplinary design optimization 20.Military aircraft design – overview 21.Environmental issues 22.Design skills 2 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Outline • Types of propulsion • Principles of air breathing engines • Engine characteristics – Engine parameters – Engine efficiency • Engine performance • Engine installation • Inlet and Nozzle • Fuel System • MDO design of engine systems 3 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Propulsion System Speed Limits 500-1000km/hr is the transport aircraft 500-1000km/hr is the speed range for most Low BPR turbofan can Mach 1.6 work efficiently up to High speed propeller Mach =0.7 design can work up to 4 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Basic Principles of Powerplants – thrust 5 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Basic Principles of Powerplants – ideal propulsion efficiency • T ma mV mVj V 0 Pt TV 0 mV j V 0 V 0 2 0 2 2 0 2 2 1 2 1 2 1 E mVj mV mVj V 1 2 0 E V V P j t PE 6
2018/4/27 Basic Principles of Powerplants- Thrust/Efficiency -Aircraft examples ideal propulsion efficiency 图上活大学 国上清大学 Propulsion efficiency discussions T=m=dr=-6) 2 ne=A正/，+1 开1D 0 123 V,should be greater than Vo 0 pro 02 123456 00 06 Vi/Vo 19a AIRSPEED m.ph. ong Basic Principles of Powerplants intake pressure recovery 圈上活大坐 Basic Principles of Power plants- exhaust and nozzle 园上活道大整 For aircraft at higher speed,it is necessary to reduce the flow velocity of the air entering the engine to below sonic speed From the thrust equation Velocity reduction by nacelle is accompanied by an increase in T=m(Vi-Vo)+mgV;+(pi-Po)A pressure,therefore an extra drag is produced Intake efficien ressu it seems pressure difference is beneficial in the contribution to thrust ahead of the engine Pressure distortion at the fan face affects the stabillity of the The design of exhaust/nozzle should be such as to engine achieve full expansion,i.e.p=po In this case,the V;contributes to more thrust. Flight conditions Takeoff conditions Variable nozzle should be used to provide optimum Cimb performance for different speed Side slip oernan Wenn ng Development of aircraft propulsion 圆上洋道大坐 Turbojet Thrust Contributions- Supersonic Flight 园上海发大坐 Most fighters Asystem of shocks Inlet duct Core engine Norzie 网 et thrust ☒ 3 + MA-60 LR0-FROP TCA North American Aviation A-5 Most Modern Jet airerafts Reduce to Subsonic High turbine blad C above the expansion creates a positive force 世xhgu时 h double-decker bus haneint on it-Chaimano erslty-Dr.W(enbin Song 2
2018/4/27 2 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Basic Principles of Powerplants – ideal propulsion efficiency • Propulsion efficiency discussions 1 2 0 E V V P j t PE 2 0 2 2 0 2 2 1 2 1 2 1 E mVj mV mVj V T ma mV mVj V 0 7 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Thrust/Efficiency - Aircraft examples Rolls-Royce, 1992 COMAC, 2016 歼10 MA700 8 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Basic Principles of Powerplants – intake pressure recovery • For aircraft at higher speed, it is necessary to reduce the flow velocity of the air entering the engine to below sonic speed • Velocity reduction by nacelle is accompanied by an increase in pressure, therefore an extra drag is produced • Intake efficiency is measured by total pressure recovery factor, defined as the ratio of total pressure at fan face and free stream ahead of the engine • Pressure distortion at the fan face affects the stability of the engine Source: https://www.tu-braunschweig.de/ism/forschung/agflzg/projekte/einlauf Flight conditions Takeoff conditions Climb Side slip 9 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Basic Principles of Power plants – exhaust and nozzle 10 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Development of aircraft propulsion MA-60 Most fighters Most Modern Jet aircrafts Early aircraft Light aircraft Agriculture aircraft High pressure turbine blades operate at temperatures roughly 300C above the melting point of the metal from which they are constructed… additionally each blade experiences a centrifugal load equivalent to having a double-decker bus hanging on it – Chairman of Rolls-Royce 11 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Turbojet Thrust Contributions – Supersonic Flight North American Aviation A-5 A system of shocks Inlet duct Core engine Nozzle Reduce to subsonic speed Subsonic expansion creates a positive force Core engine produce high temperature exhaust Engine exhaust expansion Contribution to the net thrust 12
2018/4/27 High Bypass Turbofan Engine 园上声克大学 Basic Principles of Powerplants Noise 国上清大学 Typical 1960s Design Typical 1990s Design Compressor Turbine Combustion 15- Turbine Fan Combustion Major Engine Parameters 国上活大坐 Engine Characteristics for Aircraft Designers 园上活道大整 ·For engine designers For Aircraft Designers Bypass Ratio (BPR)-mass flow ratio of the bypassed air to the air -Maximum engine thrust available in the various segments of the flight going through the core engine TOC,top of dimb thrust requirements Engine SFC toFR225 -Engine mass -Engine gecmetry generation engines -Overall Pressure Ratio(OPR),ratio of the stagnation pressure before Low maintenance cost and after the compressor stage Low weight ,0PR-3.14:1 High reliability r eficlency but with more weight -High fuel efficiency Low wetted area for podded engine These three parameters define the engine cycle orandenn ong Factors Affecting Engine Fuel Efficiency 图上洋大峰 Thermal Efficiency of Gas Generator 圆上洋文大华 Overall engine efficiency can be broken down into three Thermal efficiency can be expressed as components -The power producing component(gas generator)- thermal efficiency th ai-月 The transmission system (turbine,compressor,fan,etc.) transmission efficiency nt where noverall pressure ratio of the engine thermodynamic cycle,nfunction of the gas constant y -The propulsion jet system-propulsion efficiency 7p the fuel efficiency,but it The overall engine efficiency is calculated from the following ing te chniques equation no=h×:×p erslty-Dr.V(enbin Song 3
2018/4/27 3 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics High Bypass Turbofan Engine 13 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Basic Principles of Powerplants – Noise 14 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Major Engine Parameters • For engine designers – Bypass Ratio (BPR) – mass flow ratio of the bypassed air to the air going through the core engine • Eurojet EJ200, BPR=0.4:1 • RR Trent 1000, BRP=10:1 • Openrotor, BPR>25 – Turbine Entry Temperature (TET) – (1000~1500℃), depending on the material and cooling technology, could reach 1700℃ for next generation engines – Overall Pressure Ratio (OPR), ratio of the stagnation pressure before and after the compressor stage • WWII, Junkers Jumo 004, OPR=3.14:1 • RR Trent XWB, OPR=52:1 • The higher OPR, the higher efficiency but with more weight • These three parameters define the engine cycle 15 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Engine Characteristics for Aircraft Designers • For Aircraft Designers – Maximum engine thrust available in the various segments of the flight • TOC, top of climb thrust requirements – Engine SFC – Engine mass – Engine geometry • For engine designers, a good engine should have – Low initial price – Low maintenance cost – Low weight – High reliability – High fuel efficiency – Low wetted area for podded engine 16 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Factors Affecting Engine Fuel Efficiency • Overall engine efficiency can be broken down into three components – The power producing component (gas generator) - thermal efficiency 𝜂௧ – The transmission system (turbine, compressor, fan, etc.) – transmission efficiency 𝜂௧ – The propulsion jet system – propulsion efficiency 𝜂 • The overall engine efficiency is calculated from the following equation 𝜂 = 𝜂௧ × 𝜂௧ × 𝜂 17 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Thermal Efficiency of Gas Generator • Thermal efficiency can be expressed as 𝜂௧ = 1 − 1 𝑟 • where r=overall pressure ratio of the engine thermodynamic cycle, n=function of the gas constant γ • The higher the pressure ratio, the higher the fuel efficiency, but it is limited by turbine cooling techniques 18
2018/4/27 Transmission Efficiency 国上唐美大坐 Propulsion Efficiency 国上清大学 Transmission efficiency can be defined as Propulsion efficiency can be determined from r=1+ Ip=T BP 1+4 +2% where Vo is the aircraft speed,T is the engine thrust,and m is the engine mass flow ‘8 h nand T/m is referred to the engine specific thrust are determined by the material and manufacturing technologies 8ge-weno网 oorn enin Song Historical Trend of Engine Fuel 圈上清大坐 Historical Trend of Engine Noise Efficiency 园上活道大整 Noise Certification Downward Trend 601 Earty Comtal tubopet Chapter 4 Rule Effective 2006 写97 8智m15 ICAO Rule Chapter】 In the 1o vears from 2006.it is expected that an new engine would achieve n-t lege ecific fuel consumption,30%less length,and 30%less weight compared with an existing engine Some (not very)recent developments 圆上活天道大学 园上海发大坐 >Increased BPR-RR,CFM LEAP-X Geared Turbo Fan-P&W1000G >CR-Propfan/Open Rotor- ENGINE PERFORMANCE PARAMETERS erslty-Dr.V(enbin Song 4
2018/4/27 4 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Transmission Efficiency • Transmission efficiency can be defined as 𝜂் = 1 + BPR 1 + BPR η𝜇௧ • where BPR is bypass ratio; 𝜂 and 𝜇௧ are the fan efficiency and turbine efficiency, respectively. • Fan and turbine efficiencies are determined by the material and manufacturing technologies 19 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Propulsion Efficiency • Propulsion efficiency can be determined from 𝜂 = 2𝑉 𝑇𝑚 + 2𝑉 • where 𝑉 is the aircraft speed, 𝑇 is the engine thrust, and 𝑚 is the engine mass flow • 𝑇/𝑚 is referred to the engine specific thrust 20 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Historical Trend of Engine Fuel Efficiency In the 10 years from 2006, it is expected that an new engine would achieve 25% less specific fuel consumption, 30% less length, and 30% less weight compared with an existing engine 21 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Historical Trend of Engine Noise Ref: noise 538 22 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Some (not very) recent developments Increased BPR – RR, CFM LEAP-X Geared Turbo Fan – P&W1000G CR-Propfan/Open Rotor - 23 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics ENGINE PERFORMANCE PARAMETERS 24
2018/4/27 Engine Performance Parameters 图上活大学 Comparative Bypass Turbofan Data 国上清大学 50 63 13 Engine types 9 ·Thrust Fan diameter (m 114 Fuel consumption,SFC Flight speed(Mach number) 。Flight altitude .Engine operating conditions 以 Empirical equations,curves,data set oorornenin ong Turbofan Engine Thrust 国上活大坐 Turbofan Engine SFC Data 园上活道大整 ·BPR=8.0 ·BPR=8.0 8n3 Maximum climb thrust 一0.95 一05 065 045 Takeoff thrust 025 Maximum cruise thrust Descent thrust 02 02 102 8oame2-二Wenbin Sang Engine Price 国上洋大坐 园上海发大坐 2 ENGINE INSTALLATION 4 6 0 1 16 sty -Dr.Wenbin Song 5
2018/4/27 5 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Engine Performance Parameters • Thrust • Fuel consumption, SFC • Flight speed (Mach number) • Flight altitude • Engine operating conditions Engine types Empirical equations, curves, data set 25 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Comparative Bypass Turbofan Data 26 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Turbofan Engine Thrust • BPR=8.0 Takeoff thrust Maximum climb thrust Maximum cruise thrust Descent thrust 27 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Turbofan Engine SFC Data • BPR=8.0 28 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Engine Price 29 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics ENGINE INSTALLATION 30