前言

          目前研究船舶螺旋桨结构与性能的书籍有很多，而对船舶螺旋桨射流以及船舶螺旋桨射流对海底冲刷的研究则很少。本书系统地介绍了船舶螺旋桨射流的速度分布，并利用了计算流体力学方法和试验方法对其进行研究。

          本书的主要内容包括：螺旋桨射流的基础理论、数值模拟方法的介绍与应用、激光多普勒测速法的试验研究、螺旋桨射流揣流强度的讨论。本书介绍了轴向动量理论、平射流理论等关于螺旋桨旋转射流的基础理论。读者可以通过图片结合理论方程对螺旋桨射流有直观的理解。

          本书阐述了如何利用计算流体力学方法中的standard k-e 和standard k-w 等揣流模型对

尾流进行模拟，预测径向速度，切向速度，轴向速度和揣流强度。读者可以了解如何建立螺旋桨几何模型、生成网格的方法，并学会了如何预测螺旋桨尾流的流场。试验利用激光多普勒测速法，对射流速度进行测量，并对实验布置、数据采集、误差来源进行详细的描述，与数值模拟的结论互为补充。读者可以从中学习如何设置激光多普勒测速仪，并深入了解螺旋桨射流的物理现象和理论模型的改进。本书适合从事海洋工程、港口工程、流体力学、水力学相关的工程师、研究员、教师、研究生、高年级本科生。

         作者感谢英国贝尔法斯特女王大学对科研的资助， Hamill 博士、Robinson 博士和Raghunathan教授的在作者博士期间的细心指导。本书还获得国家自然科学基金创新群体项目（项目编号51621092 ） 、水利工程仿真与安全国家重点实验室、高新船舶与深海开发装备协同创新中心、教育部海洋能源利用与节能重点实验室、马来亚大学海洋与地球科学研究所的资助。

                                         Contents

Chapter 1 Introduction …….................…..................…..................………. 1

1. 1 Characteristics of the Ship’s Propeller Jet.............................................1

1. 2 Applications of the Ship’s Propeller Jet ……………………………………………… 2

1. 3 Scope of the Book …………………………………………………………………… 3

Chapter 2 Equations used to Predict the Velocity Components · · · · · · · · · · · · · · · · · · 5

2. 1 Concept of Propeller Jet ……………………………………………………………… 5

2. 1. 1 Plain Water Jet …………………………………………………………………… 5

2. 1. 2 Axial Momentum The。可………·……………………………………………….. 6

2. 2 Limitations of Plain Water Jet and Axial Momentum Theory ………………………… 8

2. 3 Semi-empirical Equations for a Propeller Jet ………………………………………… 9

2. 3. 1 Efflux Velocity …………………………….........……………………………… 9

2. 3. 2 Contraction of the Propeller Jet ………………………………………………… 10

2.3.3 Len♂h of the Zone of Flow Establishment ……………………………………… 11

2. 3. 4 Zone of Flow Establishment …………………………………………………… 11

2. 3. 5 Zone of Established Flow ……………………………………………………… 14

2. 3. 6 RotationaVtangential Component of Velocity …………………………………… 16

2. 3. 7 Radial Component of Velocity ………………………………………………… 17

Chapter 3 Numercial Simulations …......................….....................…… 22

3. 1 Selection of CFD Software …………………………………………………………… 2

3. 2 Selection of Hardware ………………………………………………………………… 24

3 . 3 Propeller ……………………………………………………………………………… 25

3 . 3 . 1 Propeller Configuration ………………………………………………………… 25

3. 3. 2 Basic Characteristic of Propeller ……………………………………………… 26

3. 3. 3 Propellers in Current Studies …………………………………………………… 26

3. 4 Geometry Creation …………………………………………………………………… 28

3. 5 Grid Generation ……………………………………………………………………… 30

3. 5. 1 Grid Generation Using Unstructured Grid ……………………………………… 31

3. 5. 2 Grid Generation Using Structured Grid ………………………………………… 32

3. 6 Domain Sensitivity …………........……………………….........…………………· 34

3. 6. 1 Cuboidal Domain or Cylindrical Domain ……………………………………… 34

3. 6. 2 Domain Independence for Structured Mesh …………………………………… 35

3. 6. 3 Domain Independence for Unstructured Mesh ………………………………… 36

3. 7 Grid Sensitivity ……………………………………………………………………… 36

3. 7. 1 Grid Independence of a Structured Mesh ……………………………………… 37

3. 7. 2 Grid Independence of an Unstructured Mesh …………………………………… 37

3. 8 Propeller 3 D Scanning ……………………………………………………………… 38

3. 9 Boundary Conditions and Continuum Specification ………………………………… 38

3. 10 Governing Equations of CFD ……………………………………………………… 39

3. 11 Turbulence Model …………………………………………………………………… 41

3. 11. 1 Standard k-e Turbulence Model ……………………………………………… 41

3. 11. 2 RNG k-e Turbulence Model ………………………………………………….. 42

3. 11. 3 Realizable k-e Turbulence Model …………………………………………… 43

3 . 11. 4 Standard ιw Turbulence Model ……………………………………………· 43

3 . 11 . 5 Shear Stress Transport ( SST) k-w Model …….................................... 44

3 . 11. 6 Spalart-Allmaras Model ……………………………………………………… 44

3. 11. 7 Reynolds Stress Model ( RSM)………………………………………………… 44

3. 12 Computational Demand ……………………………………………………………… 45

1 日Mesh Movement …………………………………………………………………… 45

3. 14 Discretisation Scheme ……………………………………………………………… 47

3. 15 Near-wall Treatment ………………………………………………………………… 4

3. 16 Solution Algorithm ………………………………………………………………… 48

3. 17 Convergence ………………………………………………………………………… 49

3. 18 Concluding Comments ……………………………………………………………… 49

Chapter 4 Investigation of CFD Models …........................….................. 88

4. 1 Notation ……………………………………………………………………………… 88

4. 2 Geometry Analysis …………………………………………………………………… 88

4. 3 Structured Grid or Unstructured Grid ……………………………………………… 90

4. 4 Modelling the Rotation ……………………………………………………………… 91

4. 5 Turbulence Model …………………………………………………………………… 92

4. 5. 1 Standard k-e Model in the Structured Grid …………………………………… 92

4. 5. 2 RNG k-e Model in the Structured Grid ………………………………………94

4. 5. 3 Realizable k-e Model in the Structured Grid …………………………………… 95

4. 5. 4 Standard k-w Model in the Structured Grid …………………………………… 96

4. 5. 5 SST k-w Model in the Structured Grid ………………………………………… 97

4. 5. 6 Spalart-Allmaras Model in the Structured Grid ………………………………… 97

4. 5. 7 Reynolds Stresses Model ( RSM) in the Structured Grid ……………………… 98

4. 6 Discretisation Scheme ………………………………………………………………… 98

4. 6. 1 Discretisation Scheme Using Structured Grid …………………………………… 98

4. 6. 2 Discretisation Scheme Using Unstructured Grid ………………………………… 99

4. 6. 3 Numerical Instability due to Second Order Scheme …………………………… 101

4. 7 Proposed Method …………………………………………………………………… 101

4. 8 Concluding Comments ………………………………·…………………………….. 102

Chapter 5 Application of CFD Models ….......…..... ...…………...............… 154

5. 1 Grid Generation …………………………………………………………………… 154

5. 2 Grid Independence …………………………………··……………………………· 154

5. 3 Decay of the Maximum Axial Velocity ……………………………………………… 155

5. 4 Axial Velocity Distribution ………………………………………………………… 155

5. 4. 1 Axial Velocity Distribution at Efflux Plane …………………………………… 155

5. 4. 2 Extent of the Zone of Flow Establishment …………………………………… 155

5. 4. 3 Extent of the Zone of Established Flow ……………………………………… 156

5. 5 Decay of the Maximum Tangential Velocity ………………………………………… 156

5. 6 Extent of the Tangential Component of Velocity …………………………………… 156

5. 7 Decay of the Maximum Radial Velocity …………………………………………… 157

5. 8 Extent of the Radial Component of Velocity ……………………………………… 157

5. 9 Concluding Comments ……………………………………………………………… 157

Chapter 6 LDA Setup ………………………………………………………........…· 168

6. 1 Experimental Set-up ………………………………………………………………… 168

6. 1. 1 Propeller Model ……………………………………………………………… 169

6. 1. 2 Scaling of Experimental Model ………………………………………………… 169

6. 2 Data Acquisition …………………………………………………………………… 171

6. 2. 1 Measurement Grid …………………………………………………………… 171

6. 2. 2 Laser Doppler Anemometry ………………………………………………··…· 172

6. 2. 3 Dantec LDA Measurement System …………………………………………… 173

6. 3 Source of Errors …………………………………………………………………… 174

6. 4 Particle Image Velocimetry ………………………………………………………… 175

6. 5 Concluding Comments …………·………………………………………………….. 175

Chapter 7 Experimental Measurement …........….......…..............….......… 187

7. 1 Axial Component of Velocity ……………………………………………………… 187

7. 1. 1 Axisymetric about Rotation Axis ……………………………………………… 188

7. 1. 2 Efflux Velocity ………………………………………………………………… 189

7. 1. 3 Position of the Efflux Velocity ………………………………………………… 189

7. 1. 4 Contraction of the Propeller Jet ……………………………………………… 190

7 .1. 5 Len阱of Zone of Flow Establishment…..........................… 190

7. 1. 6 Decay of the Maximum Axial Velocity within the Zone of Flow Establishment … 191

7. 1. 7 Position of Maximum Velocity from the Rotation Axis within the Zone of Flow Estahlishmen……………………………………………………… 191

7. 1. 8 Extent of the Zone of Flow Establishment …………………........…………· 192

7. 1. 9 Extent of the Zone of Established Flow ……………………………………… 193

7. 2 Tangential Component of Velocity ………………………………………………… 193

7. 2. 1 Decay of Maximum Tangential Velocity ……………………………………… 193

7. 2. 2 Extent of the Tangential Component of Velocity …………………………·….. 194

7. 3 Radial Component of Velocity ……………………………………………………… 195

7. 3. 1 Decay of the Maximum Radial Velocity ……………………………………… 195

7. 3. 2 Extent of the Radial Component of Velocity ………………………………… 195

7. 4 Concluding Comments ……………………………………………………………… 196

Chapter 8 Turbulence Intensity · · · · · · · ·….........………........…........…......... 212

8. 1 Definition of Turbulence Intensity ………………………………………………… 212

8. 1. 1 Definition of Turbulence Intensity from Dantec LDA System ………………… 213

8. 1. 2 Definition of Turbulence Intensity from Fluent ……………………………… 214

8. 1. 3 Reference Velocity for Turbulence Intensity ………........…………………· 215

8. 2 Investigation of LDA’s and CFD’s Outputs Used in Turbulence Intensity Comparison ............ 215

8. 2. 1 Component Turbulent Fluctuation …………………………………………… 216

8. 2. 2 Turbulence Intensity …………………………………………………………· 218

8. 3 Turbulence Intensity within a Ship’s Propeller Jet ………………………………… 219

8. 4 Turbulence Intensity within a Ship’s Propeller Jet Using Standard k-e Turbulence Model..................................... 221

8. 5 Turbulence Intensity within a Ship’s Propeller Jet Using RNG k-e, Realizable k-e,

Standard k-w and SST k-w Models ………………………………………………………… 221

8. 6 Turbulence Intensity within a Ship’s Propeller Jet Using Reynolds Stress Model ( RSM)...........................…223

8. 7 Turbulence Intensity within a Ship’s Propeller Jet Using Spalart-Allmaras Model

…224

8. 8 Concluding Comments ……………………………………………………………… 225

· Chapter 9 Conclusions & Recommendations …….....…...............….......... 241

9. 1 Conclusions ………………………………………………………………………… 241

9. 2 Recommendations for Future Research …………………………………………… 245

References ………………………………………………………………………………… 247