Book contents
- Frontmatter
- Contents
- Preface
- Nomenclature
- Abbreviations
- Figure Acknowledgements
- 1 Introduction
- 2 Propulsive Power
- 3 Components of Hull Resistance
- 4 Model-Ship Extrapolation
- 5 Model-Ship Correlation
- 6 Restricted Water Depth and Breadth
- 7 Measurement of Resistance Components
- 8 Wake and Thrust Deduction
- 9 Numerical Estimation of Ship Resistance
- 10 Resistance Design Data
- 11 Propulsor Types
- 12 Propeller Characteristics
- 13 Powering Process
- 14 Hull Form Design
- 15 Numerical Methods for Propeller Analysis
- 16 Propulsor Design Data
- 17 Applications
- Appendix A1 Background Physics
- Appendix A2 Derivation of Eggers Formula for Wave Resistance
- Appendix A3 Tabulations of Resistance Design Data
- Appendix A4 Tabulations of Propulsor Design Data
- Index
- References
12 - Propeller Characteristics
Published online by Cambridge University Press: 07 September 2011
- Frontmatter
- Contents
- Preface
- Nomenclature
- Abbreviations
- Figure Acknowledgements
- 1 Introduction
- 2 Propulsive Power
- 3 Components of Hull Resistance
- 4 Model-Ship Extrapolation
- 5 Model-Ship Correlation
- 6 Restricted Water Depth and Breadth
- 7 Measurement of Resistance Components
- 8 Wake and Thrust Deduction
- 9 Numerical Estimation of Ship Resistance
- 10 Resistance Design Data
- 11 Propulsor Types
- 12 Propeller Characteristics
- 13 Powering Process
- 14 Hull Form Design
- 15 Numerical Methods for Propeller Analysis
- 16 Propulsor Design Data
- 17 Applications
- Appendix A1 Background Physics
- Appendix A2 Derivation of Eggers Formula for Wave Resistance
- Appendix A3 Tabulations of Resistance Design Data
- Appendix A4 Tabulations of Propulsor Design Data
- Index
- References
Summary
Propeller Geometry, Coefficients, Characteristics
Propeller Geometry
A marine propeller consists of a number of blades (2–7) mounted on a boss, Figure 12.1. Normal practice is to cast the propeller in one piece. For special applications, built-up propellers with detachable blades may be employed, such as for controllable pitch propellers or when the blades are made from composite materials.
The propeller is defined in relation to a generator line, sometimes referred to as the directrix, Figure 12.1. This line may be drawn at right angles to the shaft line, but more normally it is raked. For normal applications, blades are raked aft to provide the best clearance in the propeller aperture. For high-speed craft, the blades may be raked forward to balance bending moments due to centrifugal forces against those due to thrust loading.
- Type
- Chapter
- Information
- Ship Resistance and PropulsionPractical Estimation of Propulsive Power, pp. 261 - 295Publisher: Cambridge University PressPrint publication year: 2011