Contents
Preface
Chapter 1 Overview 1
1.1 Contents of research 1
1.2 Objectives of research 4
1.3 Research status 4
1.4 Significance of research 9
1.5 Research approaches 12
Chapter 2 Theoretical Basis and Basic Relational Expressions 19
2.1 Analysis of the force on blade elements in design conditions 19
2.2 Basic relations among parameters 20
2.3 Differential formula of the pneumatic performance of blade element 22
2.4 Integral formula of the pneumatic performance of wind turbine 24
2.5 Summary of this chapter 26
Chapter 3 Structure of the Blade of Ideal Wind Turbine 27
3.1 The meaning of ideal blade 27
3.2 Calculating the optimal angle of attack 28
3.3 Calculation of ideal twist 30
3.4 Calculation of ideal chord 31
3.5 About ideal airfoil 33
3.6 The form of ideal blade 33
3.7 Summary of this chapter 34
Chapter 4 Highest Performance of Ideal Wind Turbine 36
4.1 Power performance and its limit 37
4.2 Torque performance and its limit 40
4.3 Lift performance and its limit 41
4.4 Thrust performance and its limit 42
4.5 Summary of this chapter 43
Chapter 5 General Performance of Ideal Wind Turbine 45
5.1 General performance of power 45
5.2 General performance of torque 51
5.3 General performance of lift 53
5.4 General performance of thrust 54
5.5 Summary of this chapter 54
Chapter 6 Flat Airfoil Wind Turbine and Its Performance 56
6.1 Flat airfoil and performance estimation 56
6.1.1 Brief introduction to the around flow lift at small angle of attack 57
6.1.2 Exploration of formula of around flow at large angle of attack 58
6.1.3 Drag coefficient of around flow at small angle of attack 65
6.1.4 The functional relationship between lift and drag 65
6.1.5 The regularity of change of lift and drag 67
6.1.6 Lift drag ratio of flat airfoil 68
6.2 Structure of ideal blade with flat airfoil 68
6.2.1 The optimal angle of attack 68
6.2.2 Ideal twist 69
6.2.3 Ideal chord 70
6.3 Performance of flat airfoil wind turbine 70
6.3.1 Power performance 72
6.3.2 Torque performance 74
6.3.3 Lift performance 76
6.3.4 Thrust performance 77
6.3.5 Startup performance 78
6.4 Summary of this chapter 80
Chapter 7 Function Airfoil and Its Main Performance 82
7.1 Function construction method for airfoil profile 82
7.1.1 Simplification of Joukowsky airfoil expression 82
7.1.2 Function construction method of general airfoil profile 84
7.1.3 Functional construction method of complex airfoil profile 86
7.1.4 Functional construction method of smooth trailing edge airfoil profile 87
7.1.5 Function expression of wind turbine blade airfoil 89
7.1.6 Airfoil parameter expression and airfoil ring view 91
7.2 Main performance calculation for function airfoil 97
7.2.1 Function airfoil speed distribution 97
7.2.2 Function airfoil pressure distribution 99
7.2.3 Function airfoil lift coefficient calculation 102
7.3 Function airfoil and flow calculation application 105
7.3.1 Airfoil expression extension 105
7.3.2 Main purpose of airfoil analytic calculation 107
7.3.3 Limitation of airfoil expression 108
7.4 Summary of the chapter 109
Chapter 8 Simplified Analysis on Ideal Blade 111
8.1 Blade chord and twist simplification 111
8.1.1 Simplification purpose and principle 111
8.1.2 Influence of drag coefficient on chord 113
8.1.3 Simplification method of chord curve 114
8.1.4 Blade lift and drag distribution 117
8.1.5 Blade attack angle and twist distribution 119
8.1.6 Outline example for simplified blade 121
8.2 Performance of simplified blade wind turbine 122
8.2.1 Power performance 122
8.2.2 Torque performance 124
8.2.3 Lift performance 126
8.2.4 Thrust performance 128
8.2.5 Starting performance 130
8.3 Impact analysis of simplification way on performance 131
8.3.1 Simplification way of blade chord 131
8.3.2 Impact of simplification way on performance 132
8.4 Summary of this chapter 133
Chapter 9 Highest Performance of Practical Wind Turbine 134
9.1 Influence of blade tip loss on structure 134
9.1.1 Basic expression 134
9.1.2 Chord curve correction 136
9.1.3 Twist curve correction 138
9.2 Highest performance calculation for practical wind turbine 139
9.2.1 Power performance calculation 139
9.2.2 Torque performance calculation 143
9.2.3 Lift performance calculation 145
9.2.4 Thrust performance calculation 148
9.3 Summary of this chapter 150
Chapter 10 Practical Blade Structure Design 151
10.1 Determination of airfoil and optimum attack angle 151
10.2 Determination of design tip speed ratio 151
10.3 Straight chord design 153
10.4 Twist correction and treatment 155
10.5 Practical blade shape design 157
10.6 Summary of this Chapter 158
Chapter 11 Practical Wind Turbine Performance Calculation 159
11.1 Power performance calculation 159
11.2 Torque performance calculation 161
11.3 Lift performance calculation 164
11.4 Thrust performance calculation 166
11.5 Summary of this Chapter 167
Chapter 12 Blade Function Design Methods 168
12.1 Mathematical model for blade of wind turbine 169
12.1.1 Coordinate transformation for airfoil function 169
12.1.2 Twist rotation transformation 170
12.1.3 Build blade mathematical model 171
12.1.4 Example for blade image generation 172
12.2 Smooth transition among airfoils 174
12.2.1 Sine curve fairing method 175
12.2.2 Transition of cylinder and airfoil 176
12.3 Functional design steps and examples 179
12.3.1 Blade functional design steps 179
12.3.2 Blade functional design example 181
12.3.3 Blade image generated by software 191
12.3.4 Solve wind turbine performance by software 196
12.4 Summary of this Chapter 198
Chapter 13 Steps of Designing Solid Model of Blade 199
13.1 Design idea 199
13.2 Insert section curves 199
13.2.1 Determine the surface equation 199
13.2.2 Insert section curves in SolidWorks 203
13.3 Do lofting to obtain surface 204
13.4 Repair and splicing of surface 204
13.5 Summary of this chapter 205
References 206
Appendices 210
Appendix Ⅰ Key terms interpretation 210
Appendix Ⅱ Meanings of main symbols 211
Appendix Ⅲ Common relation index 212