Preface
Contents
Editors andย Contributors
1 Rotorcraft Aerodynamics
1.1 Introduction
1.2 The Rotor Aerodynamic Environment
1.2.1 Figure-of-Eight Diagram
1.3 Rotorcraft Aerofoil SectionsโHistory and Current Trends
1.3.1 Modern Aerofoil Developments
1.3.2 BERP Rotor Aerofoils
1.4 Planform Effects on Rotor Performance
1.4.1 BERP Blade
1.5 Modern Rotor Design, Methods and Approaches
References
2 Experimental Methods for Aerodynamics
2.1 Introduction
2.2 The Wind Tunnel
2.3 Benefits of Wind Tunnel Instrumentation Types
2.4 Force and Moment Measurements
2.4.1 Model Positioning System and Balance Systems
2.4.2 Balance Calibration
2.5 Flow Visualisation
2.6 Pressure Measurement
2.7 Thermal Anemometry
2.7.1 Theory of Thermal Anemometry
2.7.2 Calibration
2.7.3 Use of Hot Wires
2.8 Flow Tracer Methods
2.8.1 Tracer Particle Dynamics in 1-D Flows
2.8.2 Optical Characteristics of Tracer Particles
2.8.3 Particle Image Velocimetry
2.8.4 Laser Doppler Anemometry
2.9 Case Studies and Results
2.9.1 Forces and Moments on a Model Helicopter Near an Obstacle
2.9.2 Dynamic Stall: Surface-mounted Pressure Transducers
2.9.3 Inflow to a Rotor: Flow Measurement with LDA
2.9.4 Smoke Flow Visualisation and Pressure Measurement
2.9.5 PIV of Rotor in Ground Effect in Forward Flight
2.9.6 PIV of Rotor Vortex Ring State
References
3 Rotorcraft Propulsion Systems
3.1 Rotorcraft Power Plants
3.1.1 Architecture of a Turboshaft Engine
3.2 Transmission and Power Train
3.2.1 Gearbox Considerations
3.3 Engine Power Ratings and Limitations
3.3.1 Specific Fuel Consumption
3.3.2 Engine Performance Degradation
3.4 Engine Performance Envelopes
3.4.1 Engine Simulation Models
3.4.2 Engine Emissions
3.5 Engine Intake Protection Systems
3.6 Airframe-Engine Integration
3.7 Case Study: Optimal Operation of a Multi-engine Helicopter
References
4 Rotorcraft Flight Performance
4.1 Introduction
4.2 Reliability, Availability and Maintenance
4.3 Certification Types
4.4 Point Performance Parameters
4.5 Take-off and Landing Procedures
4.6 Emergency Landing Operations
4.7 Vertical Flight Performance
4.8 Climb Performance
4.9 Ground Effects
4.9.1 Ground Operations
4.9.2 Ground Resonance
4.10 Static Trim Conditions
4.11 Helicopter Speed Stability
4.12 Mission Planning
4.13 Payload-Range
4.14 Direct Operating Costs
4.15 Performance Augmentation
4.15.1 Lift Compound
4.15.2 Thrust Compound
References
5 Tiltrotor Aeromechanics
5.1 The Tiltrotor Configuration
5.1.1 Flight Mode Classification
5.1.2 The Conversion Corridor
5.2 Tiltrotor Design Challenges
5.2.1 Hybrid Rotor/Propeller Design
5.2.2 Rotor/Wing Design
5.2.3 Whirl Flutter
5.2.4 Interaction Aerodynamics
5.3 Control Methodology
5.4 Modelling and Simulation
5.4.1 Generic Flight Mechanics Model
5.4.2 Vehicle Geometry
5.4.3 Overview of Component Aerodynamics
5.4.4 Pilot Gearings
5.4.5 Key Operating Parameters
5.5 Numerical Example
5.5.1 Effect of Control Gearings
References
6 Rotor Acoustics
6.1 Introduction
6.2 Noise Certification
6.2.1 Noise Metrics
6.3 Acoustic Sources
6.3.1 Harmonic Noise
6.3.2 Broadband Noise
6.4 Acoustic Modelling
6.4.1 Thickness and Loading
6.4.2 Compact Chord Formulation
6.4.3 Numerical Implementation
6.4.4 Blade-Vortex Interaction Noise (BVI)
6.4.5 HSI
6.4.6 Broadband Noise
6.5 Noise Reduction
References
7 Rotorcraft Control Systems
7.1 Feedback Control
7.2 Flight Dynamic Models for Rotorcraft Flight Control Design
7.3 Stability, Robustness and Performance of Feedback Control Systems
7.3.1 Feedback Stability
7.3.2 Feedback Robustness
7.3.3 Performance Assessment: Time-domain
7.3.4 Performance Assessment: Frequency-Domain
7.4 Control Design for Flight Control
7.4.1 Stability Augmentation
7.4.2 Autopilot System
7.5 Rotorcraft Flight Control System DesignโNumerical Example
7.5.1 Stability Augmentation
7.5.2 Autopilot System
7.6 Concluding Remarks
References
8 Rotorcraft Preliminary Design
8.1 Design Requirements
8.2 Design of the HelicopterโA Multi-disciplinary Task
8.2.1 Rotor Systems Team
8.2.2 Mechanical Team
8.2.3 Structures and Materials Team
8.2.4 Avionics and Electrical Systems Team
8.3 Analysis of Requirements
8.3.1 Overall Dimensions
8.3.2 Mission Requirements
8.3.3 Rotorcraft Weights
8.4 Main Rotor Sizing
8.4.1 Rotor Head Architecture
8.5 Tail Rotor Design
8.5.1 Tail Rotor Concepts
8.5.2 Tail Rotor Sizing
8.6 Blade Design Concepts
8.7 Fuselage Sizing
8.8 Landing Gear Design
8.9 Empennage Design
8.10 Aerodynamic Drag of the Helicopter
8.11 Helicopter Engine Sizing
8.11.1 Engine Power Requirements
References
Appendix A Numerical Solution of Acoustic Problems
Index