IN THE WAKE OF A MARINE CURRENT TURBINE

1,43
MB

111
stron

5277
ID University of Strathclyde

2006
rok

Table of Contents

ABSTRACT i

ACKNOWLEDGEMENT. ii

CHAPTER ONE - INTRODUCTION. 1

1.0 Background 1

1.2 Marine Current Resource. 1

1.3 Marine Current Technology 2

1.4 Environmental Impacts 2

1.5 Aims of this Project . 3

1.6 Structure of the report 3

CHAPTER TWO - LITERATURE REVIEW. 5

2.0 Introduction . 5

2.1 Marine Current Energy Resource 5

2.1.1 Resource Basics 5

2.1.2 Resource Estimates . 8

2.2 Marine Current Energy Extraction Technologies 9

2.2.1 Mode of Operation 10

2.2.2 Support Structure Concepts 11

2.2.3 Prototypes 12

2.2.3.1 Seaflow. 13

2.2.3.2 Tidal Stream Turbine . 14

2.2.3.3 Tidal Fence (Davis Hydro Turbine). 15

2.2.3.4 The Stingray Tidal Stream Generator 16

2.2.4 Emerging Technologies 18

2.2.4.1 TidEI Tidal Stream Generator 18

2.2.4.2 Lunar system 19

2.2.5 Technology Challenges. 19

2.3 Environmental Impacts of Marine Current Development . 21

2.3.1 The Marine Environment 22

2.3.3 Salinity 23

2.3.3.1 Salinity Profiles 23

2.3.3.2 Importance of Salinity 25

2.3.4 Water Temperature . 26

2.3.4.1 Temperature Profile . 26

2.3.4.2 Significance of Temperature 28

2.3.5 Sediment Transport . 28

2.3.6 Turbidity 29

2.3.6.1 Significance of Turbidity . 29

2.4 Overview of Computational Fluid Dynamics (CFD) 30

2.4.1 What is Computational Fluid Dynamics? . 31

2.4.2 How does a CFD code work? . 32

2.4.2.1 Pre- processor. 32

2.4.2.2 Solver . 33

2.4.2.3 Post-processor 36

2.4.3 Problem Solving With CFD 36

2.5 Wind Analogy 37

2.5.1 CFD Modelling in Wind Energy Industry 37

2.5.2 Sample Studies 38

CHAPTER THREE - ANALYTICAL FRAMEWORK . 40

3.0 Introduction . 40

3.1 Natural Open Channels 40

3.2.1 Velocity Distribution in a Channel Section 40

3.3 Energy Conversion Principles . 44

3.4 Turbulence Modelling . 46

3.4.1 General Equations . 47

3.4.3 Turbulence Models . 48

3.4.4 Turbulence Models in FLUENT. 49

3.4.4.1 The Zero-Equation Model 49

3.4.4.1 The One- Equation Model 50

3.4.4.1 The Two-Equation Model 50

CHAPTER FOUR: METHODOLOGY. 53

4.0 Introduction . 53

4.1 Modelling and Simulation Procedure 53

4.1.1 Pre-processing. 53

4.1.1.1 Creation of the Simulation Model 53

4.1.1.2. Processing of Simulation Model for Simulation. 54

4.1.3 Initialisation and Solving the Model. 55

4.1.4 Post-processing . 56

4.1.5 Validation of CFD Solution 56

4.1.6 Further Investigation . 56

4.2 Inputs and Assumptions. 56

4.2.1 Channel Dimension. 56

4.2.2 Turbine Configuration. 57

4.2.3 Meshed Model. 58

4.2.4 Fluid Properties . 59

4.2.5 Boundary Types and Conditions. 60

4.3 Model Validation. 62

4.3.1 Flow Equations of a Simple Channel 62

4.3.2 Boundary Conditions 64

4.3.3 Determination of Average Velocity along Channel Length . 64

CHAPTER FIVE – RESULTS AND DISCUSSION 66

5.0 Introduction . 66

5.1 Results for a Surface Current Speed of 3 m/s 66

5.1.1 Resource 66

5.1.2 Turbine 1 . 69

5.1.2.1 Plan View of Turbine 1 in Channel . 69

5.1.2.2 Front View of Turbine 1 in Channel 71

5.1.2.3 Side View of Turbine 1 in Channel . 72

5.1.3 Turbine 2 . 74

5.1.3.1 Plan View of Turbine 2 in Channel . 75

5.1.3.2 Front View of Turbine 2 in Channel 76

5.1.3.3 Side View of Turbine 2 in Channel . 77

5.1.4 Comparison of Results for Turbine 1 and Turbine 2 78

5.2 Results for a Surface Current Speed of 4 m/s 79

5.2.1 Resource 79

5.2.2 Turbine 1 . 80

5.2.2.1 Plan View of Turbine 1 in Channel . 80

5.2.2.2 Front View of Turbine 1 in Channel 81

5.2.2.3 Side View of Turbine 1 in Channel . 82

5.2.3 Turbine 2 . 83

5.2.3.1 Plan View of Turbine 2 in Channel . 83

5.2.3.2 Front View of Turbine 2 in Channel 84

5.2.3.3 Side View of Turbine 2 in Channel . 85

5.2.4 Comparison of Results 86

5.3 Results for a Surface Current Speed of 1 m/s 87

5.3.1 Resource 87

5.3.2 Turbine 1 . 88

5.3.2.1 Plan View of Turbine 1 in Channel . 88

5.3.2.2 Front View of Turbine 1 in Channel 89

5.3.2.3 Side View of Turbine 1 in Channel . 90

5.3.3 Turbine 2 . 91

5.3.3.1 Plan View of Turbine 2 in Channel . 91

5.3.3.2 Front View of Turbine 2 in Channel 92

5.3.3.3 Side View of Turbine 2 in Channel . 93

5.3.4 Comparison of Results 94

CHAPTER SIX – CONCLUSION AND FUTURE WORK. 95

6.1 Conclusion . 95

6.1.1 Depth of Deployment 95

6.1.2 Changing Current Speed . 95

6.2 Recommendation . 96