Thermodynamics of. Turbomachinery. Fluid Mechanics and. Sixth Edition. S. L. Dixon, B. Eng., Ph.D. University of Liverpool, C. A. Hall, Ph.D.

Size: px

Start display at page:

Download "Thermodynamics of. Turbomachinery. Fluid Mechanics and. Sixth Edition. S. L. Dixon, B. Eng., Ph.D. University of Liverpool, C. A. Hall, Ph.D."

Mariah Preston
5 years ago
Views:

1 Fluid Mechanics and Thermodynamics of Turbomachinery Sixth Edition S. L. Dixon, B. Eng., Ph.D. Honorary Senior Fellow, Department of Engineering, University of Liverpool, UK C. A. Hall, Ph.D. University Lecturer in Turbomachinery, University of Cambridge, UK AMSTERDAM BOSTON HEIDELBERG LONDON NEW YORK OXFORD PARIS SAN DIEGO ELSEVIER SAN FRANCISCO SINGAPORE SYDNEY TOKYO Butlerworth-Heinemann is an imprint of Elsevier

2 Contents Preface to the Sixth Edition Acknowledgments List of Symbols xi xl" xv CHAPTER 1 Introduction: Basic Principles Definition of a Turbomachine Coordinate System The Fundamental Laws The Equation of Continuity The First Law of Thermodynamics The Momentum Equation The Second Law of Thermodynamics Entropy Bernoulli's Equation 1' 1.9 Compressible Flow Relations Definitions of Efficiency Small Stage or Polytropic Efficiency IB 1.12 The Inherent Unsteadiness of the Flow within Turbomachines 24 References 26 Problems 26 CHAPTER 2 Dimensional Analysis: Similitude Dimensional Analysis and Performance Laws Incompressible Fluid Analysis Performance Characteristics for Low Speed Machines Compressible Fluid Analysis Performance Characteristics for High Speed Machines Specific Speed and Specific Diameter Cavitation 47 References 49 Problems 50 CHAPTER 3 Two-Dimensional Cascades Introduction Cascade Geometry Cascade Flow Characteristics Analysis of Cascade Forces Compressor Cascade Performance 68 V

3 vi Contents 3.6 Turbine Cascades 78 References 92 Problems 94 CHAPTER 4 Axial-Flow Turbines: Mean-Line Analysis and Design Introduction Velocity Diagrams of the Axial-Turbine Stage Turbine Stage Design Parameters Thermodynamics of the Axial-Turbine Stage Repeating Stage Turbines Stage Losses and Efficiency Preliminary Axial Turbine Design Styles of Turbine Effect of Reaction on Efficiency Diffusion within Blade Rows The Efficiency Correlation of Smith (1965) Design Point Efficiency of a Turbine Stage Stresses in Turbine Rotor Blades Turbine Blade Cooling Turbine Flow Characteristics 133 References 136 Problems 137 CHAPTER 5 Axial-Flow Compressors and Ducted Fans Introduction Mean-Line Analysis of the Compressor Stage Velocity Diagrams of the Compressor Stage Thermodynamics of the Compressor Stage Stage Loss Relationships and Efficiency Mean-Line Calculation Through a Compressor Rotor Preliminary Compressor Stage Design Simplified Off-Design Performance Multi-Stage Compressor Performance High Mach Number Compressor Stages Stall and Surge Phenomena in Compressors Low Speed Ducted Fans Blade Element Theory Blade Element Efficiency Lift Coefficient of a Fan Aerofoil 176 References 177 Problems 179

4 Contents vii CHAPTER 6 Three-Dimensional Flows in Axial Turbomachines Introduction Theory of Radial Equilibrium The Indirect Problem The Direct Problem Compressible Flow Through a Fixed Blade Row Constant Specific Mass Flow Off-Design Performance of a Stage Free-Vortex Turbine Stage Actuator Disc Approach Computer-Aided Methods of Solving the Through-Flow Problem Application of Computational Fluid Dynamics to the Design of Axial Turbomachines Secondary Flows 210 References 212 Problems 213 CHAPTER 7 Centrifugal Pumps, Fans, and Compressors Introduction Some Definitions Thermodynamic Analysis of a Centrifugal Compressor Diffuser Performance Parameters Inlet Velocity Limitations at the Eye Optimum Design of a Pump 7.7 Optimum Design of a Centrifugal Compressor Inlet 230 Inlet Slip Factor Head Increase of a Centrifugal Pump Performance of Centrifugal Compressors The Diffuser System Choking In a Compressor Stage 256 References 258 Problems 259 CHAPTER 8 Radial Flow Gas Turbines Introduction Types of Inward-Flow Radial Turbine Thermodynamics of the 90 IFR Turbine Basic Design of the Rotor Nominal Design Point Efficiency Mach Number Relations Loss Coefficients in 90 IFR Turbines 276

5 viii Contents 8.8 Optimum Efficiency Considerations Criterion for Minimum Number of Blades Design Considerations for Rotor Exit Significance and Application of Specific Speed Optimum Design Selection of 90 IFR Turbines Clearance and Windage Losses Cooled 90 IFR Turbines 297 References 298 Problems 299 CHAPTER 9 Hydraulic Turbines Introduction Hydraulic Turbines The Pelton Turbine Reaction Turbines The Francis Turbine The Kaplan Turbine Effect of Size on Turbomachine Efficiency Cavitation Application of CFD to the Design of Hydraulic Turbines The Wells Turbine Tidal Power 346 References 349 Problems 350 CHAPTER 10 Wind Turbines Introduction Types of Wind Turbine Outline of the Theory Actuator Disc Approach Estimating the Power Output Power Output Range Blade Element Theory The Blade Element Momentum Method Rotor Configurations The Power Output at Optimum Conditions HAWT Blade Section Criteria Developments in Blade Manufacture Control Methods (Starting, Modulating, and Stopping) Blade Tip Shapes Performance Testing 406

6 10.16 Performance Prediction Codes Environmental Considerations 408 References 411 Problems 413 Appendix A: Preliminary Design of an Axial Flow Turbine for a Large Turbocharger 415 Appendix B: Preliminary Design of a Centrifugal Compressor for a Turbocharger 425 Appendix C: Tables for the Compressible Flow of a Perfect Gas 433 Appendix D: Conversion of British and American Units to SI Units 445 Appendix E: Answers to Problems 447 Index 451

Principles of. Turbomachinery. Seppo A. Korpela. The Ohio State University WILEY A JOHN WILEY & SONS, INC., PUBLICATION

Principles of. Turbomachinery. Seppo A. Korpela. The Ohio State University WILEY A JOHN WILEY & SONS, INC., PUBLICATION Principles of Turbomachinery Seppo A. Korpela The Ohio State University WILEY A JOHN WILEY & SONS, INC., PUBLICATION CONTENTS Foreword xiii Acknowledgments xv 1 Introduction 1 1.1 Energy and fluid machines