Chapter 1: Introduction to Automobile Aerodynamics...1

Transcription

1 Preface...xv Acknowledgments...xix Chapter 1: Introduction to Automobile Aerodynamics Scope The Role of Aerodynamics in Vehicle Design The Character of Vehicle Aerodynamics Related Fields Historical Development of Vehicle Aerodynamics Literature Ahead of Its Time Dominant Reference Number c D Creating Shapes for Cars Borrowed Shapes The Streamline Era Early Investigations with Parameters From Horseless Carriage to Automobile Stamping Bathtub Body One-Volume Bodies Rear-End Shapes Kamm-Back Fastback Notchback Hatchback Directional Stability Commercial Vehicles Motorcycles and Helmets Internal Flows Engine Compartment Passenger Compartment Development Strategies Detail Optimization Shape Optimization Limit Strategy Design and Aerodynamics Development Tools Wind Tunnels Rating v 6584_Book.indb 5

2 Classical Approach CFD Integrated Methods Chapter 2: The Physical Principles of Aerodynamics Basic Equations in Fluid Dynamics Conservation Laws Kinematics and Dynamics of Flow Fields The Continuity Equation The Euler Equation The Bernoulli Equation Potential Theory The Navier- Stokes Equation Integral Forms of the Conservation Laws Dynamics of Inviscid Flow Interpreting Streamline Patterns Planar Model Flows Vortex Flows The Dynamics of the Frictional Flow The Reynolds Number The Prandtl Boundary Layer Concept Boundary Layer Separation Boundary Layer Turbulence Drag of Simple Bodies Multi-Body Systems Pipe Systems with Internal Flow Appendix Density and Viscosity of Air Compressibility Effects Chapter 3: Consumption and Performance The Significance of Aerodynamic Drag Theory of Driving Resistance Rolling Resistance Aerodynamic Drag Grade Resistance Acceleration Overall Driving Resistance Example Performance Acceleration and Elasticity Ascending Ability Top Speed Consumption Calculating Fuel Consumption vi 6584_Book.indb 6

3 3.4.2 Consumption Measurement and CO 2 and Energy Equivalents Driving Cycles History New European Driving Cycle (NEDC) NEDC Cycle for Hybrid Drives United States Cycles Asian Cycles WLTP Worldwide Harmonized Light Vehicles Test Procedure Realistic Driving Cycles Possibilities for Reducing Fuel Consumption Energy Flow Diagram Engine Efficiency and Engine Maps Ancillary Components Transmission Vehicle Mass Rolling Resistance Aerodynamic Drag Reducing Aerodynamic Drag Possibilities for Reducing Resistance Weight Equivalency Amortization Analysis CO 2 Legislation and Labels EU Legislation CO 2 Labels in the EU Legislation in the United States CO 2 Labels in the United States Legislation in Asia Chapter 4: Aerodynamic Forces and Their Influence on Passenger Vehicles Aerodynamic Forces and Force Coefficients Buckingham Π Theorem Flow Field Around Cars Dead Wake Longitudinal Vortices Internal Flow Environmental Influences Influence of the Reynolds Number Analysis of Aerodynamic Drag Components Pressure and Friction Drag Microdrag Analysis by Individual Components vii 6584_Book.indb 7

4 4.4 Other Components of Aerodynamic Force and Aerodynamic Moment Lift and Pitching Moment Side Force and Yaw Moment Roll Moment Influence on Aerodynamic Forces The Influence of Basic Shape Cooling Air Effect Add-On Parts Interference The Aerodynamic Development Process Goal Definition Project Milestones and Tools Examples Drag and Lift of Passenger Cars in Production Overview of Competitors by Vehicle Class Drag Surface Area c D A x Intercomparison in Accordance with EADE Influence of Vehicle Concepts Influence of Equipment and Engine Driving on the Ceiling? Future Development Reference Bodies SAE Reference Body Ahmed Body DrivAer Body Chapter 5: Aerodynamics and Driving Stability Unsteady Aerodynamic Forces and Moments Overtaking Maneuvers Side Wind Dynamic Driving Effects Single-Track Model Reaction to Lift Forces Aerodynamic Axle Load Relief Settings Reaction to Crosswinds Chapter 6: Functionality, Safety, and Comfort Component Loads Component Loads and Pinpointing Them Doors, Flaps, and Outside Mirrors Windshield Wipers Comfort When Driving with the Top Down Objective viii 6584_Book.indb 8

5 6.2.2 Airflow with Convertible Top Open Wind Noise Thermal Comfort Design Solutions for Convertibles Design Solutions for Sunroofs Prevention of Vehicle Soiling Basics of Vehicle Soiling External Contamination Vehicle-Induced Contamination Chapter 7: Cooling and Internal Flow Cooling Requirements Representative Operating Conditions Components and Systems Other Requirements Cooling System Engine Cooling System Circuit Fundamentals of Heat Transfer Design of Heat Exchanger Heat Exchangers in the Vehicle Internal Flow Operating Conditions Cooling Module Fan Optimizing the Overall System Calculation of the Cooling Air Mass Flow Influence Parameters of the Internal Flow Air Intakes and Cooling Air Ducts Cooling Matrix Fan Engine Compartment Cooling Air Outlets Measurement Technology for Cooling Airflow Vane Anemometers Pressure Measurements Optical Measuring Methods Hot-Wire Anemometry Chapter 8: Aeroacoustics The Influence of Airflow on the Interior and Exterior Noise of Motor Vehicles Aerodynamic Noise Generation Aeroacoustic Measuring Systems Aeroacoustic Wind Tunnels ix 6584_Book.indb 9

6 8.3.2 Measuring Interior Noise Measuring Exterior Noise Measuring Structure- Borne Sound Sound Source Location with Special Instruments Main Noise Sources and Options for Their Reduction Leaks Rear View Mirrors Windshield Wipers Antennas A-Pillar Cavity Resonances Sun Roof Opening Noise Wheel Housings Underbody Reduction of Interior Noise by Using Special Acoustic Glass Windows Convertibles Psycho-Acoustic Aspects Assessing Different Behavior Under Yaw Conditions Simulation with Static Vortex Generators Simulation with Dynamic Vortex Generators Noise Synthesis Chapter 9: High-Performance Vehicles Introduction Definition Preview Outline of the History Racing Cars Record-Breaking Vehicles Sports Cars Vehicle Classes Race Tracks Regulations Aerodynamics, Performance, and Handling Characteristics Drag Downforce Balance Road Performance Efficiency Cooling and Ventilation Oblique Incident Flow Slipstream x 6584_Book.indb 10

7 9.7 Aerodynamics of Components Basic Body Wings Spoiler and Gurneys Ground Effect Diffusers Inlets and Outlets Air Guiding Elements (Vanes) Wheels Chapter 10: Commercial Vehicles Target Group Driving Resistances and Fuel Consumption History of Commercial Vehicle Aerodynamics Principles of Commercial Vehicle Aerodynamics Straight/Oblique Flow Legislative Framework Tools for Optimizing Commercial Vehicle Aerodynamics Challenges Posed by Commercial Vehicles Model- Scale Wind Tunnel Full- Scale Wind Tunnel CFD Simulation Test Drives with Wheel Hub Measurement Device Optimizing Aerodynamic Drag on Trucks Characteristic Airflow and Pressure Conditions Cab Mirrors and Attachments on the Cab Airflow Through the Engine Compartment Chassis Semitrailers and Bodies Concept Vehicles Optimizing Aerodynamic Drag on Buses and Coaches Characteristic Airflow and Pressure Conditions Front Rear View Mirrors Windscreen Wipers Underbody Wheels and Wheel Covers Airflow Through the Engine Compartment Rear Aerodynamic Interaction Nose-to-Tail Driving Tipping and Susceptibility to Side Winds Aerodynamic Loads on Components xi 6584_Book.indb 11

8 Dust Turbulence Intake of Warm Air Management of Exhaust Gas Vehicle Soiling Task Description and Testing Methods Foreign Soiling Self-Soiling Chapter 11: Motorcycle Aerodynamics Introduction Historical Review and Current Types History of Motorcycle Aerodynamics Current Motorcycle Categories Special Bikes Aerodynamic Tasks Aerodynamic Forces and Moments Aerodynamics and Longitudinal Dynamics Aerodynamics and Lateral Dynamics Cooling and Internal Flow Wind and Weather Protection Aeroacoustics Development Methods Development Process Simulation (CFD) Wind Tunnel Road Test Outlook The Future of Development Methods Aerodynamic Design Practical Examples Measures to Optimize Drag and Lift Design of Internal Flows, Cooling, and Heat Protection Measures for Wind and Weather Protection Outlook Chapter 12: Helmets Head Protection Technology Motorcycle Helmets Aerodynamics Aeroacoustics Ventilation and Rain Tests Helmets for Open Race Cars History Aerodynamics and Ventilation Acoustics xii 6584_Book.indb 12

9 12.4 Measurement and Simulation Technology Introduction Wind Tunnel Aerodynamic Forces Aeroacoustic and Artificial-Head-Measurement Technology Computational Fluid Dynamics (CFD) Chapter 13: Wind Tunnels and Measurement Technique Scope of Wind Tunnels Wind Tunnel Physics Design and Function of Wind Tunnels Wind Tunnel Nozzle The Test Section The Collector Plenum Diffusers Turning Vanes Flow Conditioning Screens Honeycombs Acoustic and Anti- Buffeting Measures Ground Simulation Unsteady Flow and Gust Simulation Wind Tunnel Correction Methods Wind Tunnel Measurements Test Sequence Measurement of Flow Velocity Pressure Measurements Measurements of Aerodynamic Loads Flow Visualization Investigation of Vehicle Soiling Engine Cooling Tests Heating and Climatization Tests On-Road Measurements Additional Equipment in Climatic and Thermal Wind Tunnels Model Testing Dimensionless Numbers Existing Wind Tunnels for Motor Vehicles Full- Scale Wind Tunnels Model- Scale Wind Tunnels Climatic and Thermal Wind Tunnels Overview and Correlation Measurements Outlook xiii 6584_Book.indb 13

10 Chapter 14: Numerical Methods Simulation of Three- Dimensional Viscous Flows Requirements and Properties of CFD Methods Basics of Kinetic Theory Lattice Methods Navier-Stokes Methods Potential Flow Methods (BEM) One- Dimensional Methods for Cooling Module Design Rotating Geometries (Wheels, Fans) Porous Media (Heat Exchanger) The Solution Process Hardware and Benchmarking Integration of CFD in the Development Process Outlook Computational Aeroacoustics for Motor Vehicles Introduction Calculation of Aerodynamic and Aeroacoustic Sources Sources and Exterior Sound Field Transfer into the Vehicle Cabin Examples of Applications Conclusion and Outlook Abbreviations Symbols Literature The Authors Index xiv 6584_Book.indb 14