Electric Aircraft Dynamics: A Systems Engineering Approach

Description

Electric Aircraft Dynamics: A Systems Engineering Approach surveys engineering sciences that underpin the dynamics, control, monitoring, and design of electric propulsion systems for aircraft. It is structured to appeal to readers with a science and engineering background and is modular in format. The closely linked chapters present descriptive material and relevant mathematical modeling techniques. Taken as a whole, this groundbreaking text equips professional and student readers with a solid foundation for advanced work in this emerging field. Key Features: Provides the first systems-based overview of this emerging aerospace technology Surveys low-weight battery technologies and their use in electric aircraft propulsion Explores the design and use of plasma actuation for boundary layer and flow control Considers the integrated design of electric motor-driven propellers Includes PowerPoint slides for instructors using the text for classes Dr. Ranjan Vepa earned his PhD in applied mechanics from Stanford University, California. He currently serves as a lecturer in the School of Engineering and Material Science, Queen Mary University of London, where he has also been the programme director of the Avionics Programme since 2001. Dr. Vepa is a member of the Royal Aeronautical Society, London; the Institution of Electrical and Electronic Engineers (IEEE), New York; a Fellow of the Higher Education Academy; a member of the Royal Institute of Navigation, London; and a chartered engineer. Cover Half Title Title Page Copyright Page Dedication Table of Contents Preface Acronyms Chapter 1 Introduction 1.1 Introduction to Electric Aircraft 1.2 The Systems Engineering Method 1.3 Hybrid and All-Electric Aircraft: Examples 1.4 Battery Power 1.5 Range and Endurance of Electric Aircraft 1.6 Propulsion Motors 1.7 Propellers, Aeroacoustics and Low Noise Design 1.8 Electric Propulsion Issues 1.9 Key Technology Limitations 1.10 Future Work Chapter Summary References Chapter 2 Electric Motors 2.1 Introduction to DC Motors 2.1.1 DC Motor Principles 2.1.2 DC Motor Characteristics 2.1.3 Classification of DC Motors 2.1.4 Dynamic Modeling of DC Motors 2.1.5 Control of DC Motors 2.2 Introduction to AC Motors 2.2.1 Synchronous Motors 2.2.2 Three-Phase Motors 2.2.3 Loading and Back-EMF in Synchronous Motors 2.2.4 Characteristics of AC Motors 2.2.5 Induction Motors 2.2.6 Squirrel-Cage Rotor 2.2.7 Controlling AC Motors 2.3 Reluctance Motors: Reluctance Principle 2.3.1 Types of Construction 2.3.2 Reluctance Torque 2.3.3 Switched Reluctance Motor 2.3.4 Operation of a Switched Reluctance Motor 2.4 Brushless DC Motors 2.4.1 Brushless or Electronic Commutation 2.4.2 Dynamic Modeling 2.4.3 Switching and Commutation Chapter Summary References Chapter 3 Batteries 3.1 Introduction to Batteries 3.1.1 Battery Structure and Specifications 3.1.2 Rechargeable Batteries 3.1.3 Charge, Capacity and Discharge Features 3.1.4 Temperature Effects and Capacity Fading 3.2 Battery Dynamic Modeling: Physical, Empirical, Circuit and Hybrid Models 3.2.1 Battery SOC Estimation 3.3 Types and Characteristics of Batteries 3.3.1 Lithium-Ion (Li-Ion) Batteries 3.3.2 Gel Polymer Electrolytes 3.3.3 Lithium–Sulfur (Li–S) Batteries 3.3.4 Metal-Air and Li-Air Batteries 3.4 Applications 3.4.1 Batteries for Electric Aircraft Chapter Summary References Chapter 4 Permanent Magnet Motors and Halbach Arrays 4.1 Motors for All-Electric Propulsion 4.2 High Torque Permanent Magnet Motors 4.2.1 Rare Earth Elements 4.2.2 Neodymium Magnets and Samarium–Cobalt Magnets 4.3 Magnetic and Electromagnetic Effects 4.3.1 Magnetic Materials on a Microscopic Scale 4.3.2 Diamagnetism 4.3.3 Paramagnetism 4.3.4 Remnant Magnetic Moment 4.3.5 Ferromagnetism 4.3.6 Curie Temperature 4.3.7 Magneto-Striction 4.3.8 Ferrimagnetism 4.3.9 The Maximum Energy Product 4.3.10 Coercivity 4.3.11 High Temperature Coercivity 4.3.12 Curie Temperature of NdFeB 4.3.13 Intrinsic Coercivity 4.3.14 Intrinsic and Normal Coercivity Compared 4.3.15 Permanent Magnets with Reduced Rare Earth Elements 4.4 Halbach Array Motors 4.4.1 Complex Halbach Arrays 4.4.2 Ring Type Structures 4.5 Modeling the Magnetic Field Due to a Halbach Array Chapter Summary References Chapter 5 Introduction to Boundary Layer Theory and Drag Reduction 5.1 Principles of Airfoil and Airframe Design 5.2 Flow Over an Aerofoil 5.3 Aerodynamic Drag 5.4 Boundary Layer Flow 5.4.1 The Navier–Stokes (NS) Equations 5.4.2 Viscous Energy Dissipation 5.4.3 Non-Dimensionalizing and Linearizing the NS Equations 5.4.4 Analysis in the Boundary Layers 5.4.5 Boundary Layer Equations 5.4.6 Vorticity and Stress in a Boundary Layer 5.4.7 Two-Dimensional Boundary Layer Equations 5.4.8 The Blasius Solution 5.4.9 The Displacement, Momentum and Energy Thicknesses 5.5 Computation of Boundary Layer Velocity Profiles 5.5.1 The von Karman Method: The Integral Momentum Equation 5.5.2 Wall Shear Stress, Momentum Thickness, Displacement Thickness and Boundary Layer Thickness for the Blasius Solution 5.5.3 The Methods of Pohlhausen and Holstein and Bohlen 5.5.4 Refined Velocity Profiles within the Boundary Layer 5.5.5 Laminar Boundary Layers: Integral Methods Using Two Equations 5.5.6 Effect of Suction, Blowing or Porosity 5.5.7 Reduction of the Equations 5.5.8 Special Cases 5.5.9 Thwaites Correlation Technique 5.6 Transition and Separation 5.6.1 Walz–Thwaites’ Criterion for Transition/Separation 5.6.2 The Transitional Boundary Layer 5.7 Turbulent Boundary Layers 5.7.1 Predicting the Turbulent Boundary Layer 5.7.2 The Entrainment Equation Due to Head 5.7.3 Drela’s Method for a Turbulent Boundary Layer 5.8 Strategy for Aircraft Drag Reduction Chapter Summary References Chapter 6 Electric Aircraft Propeller Design 6.1 Introduction 6.2 Aerofoil Sections: Lift and Drag 6.3 Momentum Theory 6.4 Actuator Disk 6.5 Blade Element Theory 6.6 Dynamics and Modeling of the Inflow 6.7 Integrating the Thrust and Torque 6.8 Blade Element Momentum Theory 6.8.1 Application to Ducted Propellers 6.9 Lifting Line Theory 6.10 Blade Circulation Distribution: Potential Flow-Based Solutions 6.11 Standard Propeller Features and Design Considerations 6.12 Propellers for Distributed Propulsion Chapter Summary References Chapter 7 High Temperature Superconducting Motors 7.1 High Temperature Superconductors (HTS) 7.1.1 The Meissner State and the Meissner Effect 7.1.2 Features of Superconducting Materials 7.2 HTS Motors 7.2.1 HTS DC Motors 7.2.2 HTS Synchronous and Induction Motors 7.2.3 Cryostats for HTS Motors 7.2.4 Control of 3-Phase HTS PMSM 7.3 Homopolar Motors 7.3.1 Superconducting Homopolar Motors 7.4 Design of HTS Motors for Aircraft Propulsion Chapter Summary References Chapter 8 Aeroacoustics and Low Noise Design 8.1 Aeroacoustic Analogies 8.1.1 Sound Pressure Level 8.2 Integral Methods of Lighthill, Ffowcs Williams and Hawkings, and Kirchhoff 8.3 Monopoles, Dipoles and Quadrupoles 8.3.1 Tonal Characterization of Aeroacoustically Generated Noise 8.4 Application to Propellers and Motors 8.4.1 Sources of Airfoil and Propeller Noise 8.4.2 Hamilton-Standard Procedure for Estimating the Noise Due to Propeller Aerodynamic Loading 8.5 Theoretical Modeling of the Noise Fields 8.5.1 Theoretical Modeling of the Propeller Noise Fields 8.5.2 Farassat’s Formulation of the FW–H Equation 8.5.3 Formulation of the Far-Field Noise Based on a Rotating Source 8.5.4 Lilley’s Analogy and Its Application to Ducts Chapter Summary References Chapter 9 Principles and Applications of Plasma Actuators 9.1 Flow Control and Plasma Actuation 9.2 Passive Methods of Flow Control 9.2.1 Riblets 9.2.2 Dimples 9.2.3 Fences 9.2.4 Vortex Generators (VGs) and Micro-VGs 9.2.5 Vortilons 9.2.6 Winglets 9.2.7 Cavities 9.2.8 Gurney Flaps 9.3 Passive Methods Coupled with Plasma Actuation 9.4 Reduction of Skin-Friction Drag by Feedback 9.4.1 Feedback Control of Transition 9.4.2 Modeling the Flow Due to DBD Plasma Actuators 9.4.3 Decomposition of Simulated Flow Features 9.4.4 Application of Wavelet Decomposition and De-Noising 9.4.5 A Review of Wavelet Decomposition Based on the Wavelet Transform 9.4.6 Application to the Regulation of Laminar Flow over an Airfoil 9.5 Control Laws for Active Flow Control 9.5.1 Integral Equations for the Boundary Layer 9.5.2 The Inverse Boundary Layer Method: Uniform Solutions 9.5.3 Uniform and Prescribed Shape Factor 9.5.4 The Vorticity–Velocity Formulation with Control Flow Inputs 9.5.5 Active Control of Velocity Profiles 9.5.6 Hybrid Active Laminar Flow Control with Plasma Actuation 9.5.7 Application of the Control Laws to a Typical Airfoil Chapter Summary References Chapter 10 Photovoltaic Cells 10.1 History of the Photoelectric Effect 10.2 Semiconductors: Silicon Photo Diodes 10.3 Photoconductive Cells 10.4 The Photovoltaic Effect 10.4.1 The Photovoltaic Cell: The Solar Cell 10.4.2 Solar Cell Characteristics 10.4.3 Modeling the Power Output of a Solar Cell 10.4.4 Maximum Power Point Tracking 10.4.5 The Shockley–Queisser Limit 10.5 Multi-Junction Silicon PV Cells 10.5.1 Modeling the Power Output of Multi-Junction Cells Chapter Summary References Chapter 11 Semiconductors and Power Electronics 11.1 Semiconductors and Transistors 11.1.1 Semiconductors and Semiconductor Diodes 11.1.2 Transistors 11.2 Power Electronic Devices 11.2.1 Power Diodes: A Three-Layered Semiconductor Device 11.2.2 Thyristors and Silicon Controlled Rectifier (SCR) 11.2.3 Controlled Devices: GTO and GTR 11.2.4 The MOSFET 11.2.5 The IGBT 11.2.6 Applications Chapter Summary References Chapter 12 Flight Control and Autonomous Operations 12.1 Introduction to Flight Control 12.1.1 Range and Endurance of an Electric Aircraft 12.1.2 Equivalent Air Speed, Gliding Speed and Minimum Power to Climb 12.2 Flight Path Optimization 12.2.1 The Optimal Control Method 12.2.2 Cruise Optimization: Optimal Control Formulation 12.2.3 Optimization Procedure: Optimum Cruise Velocity, Optimum Trajectory Synthesis 12.2.4 Modeling with the Peukert Effect 12.3 Integrated Flight and Propulsion Control 12.3.1 Model-Based Design of Control Laws for Distributed Propulsion-Based Flight Control 12.4 Flight Management for Autonomous Operation 12.4.1 Autonomous Control Systems 12.4.2 Route Planning 12.4.3 Mission Planning for Autonomous Operations 12.4.4 Systems and Control for Autonomy 12.5 Flight Path Planning 12.5.1 Path Planning in Three Dimensions Using a Particle Model 12.5.2 Path Planning in the Horizontal Plane 12.5.3 Path-Following Control Chapter Summary References Index