Wind Energy In The Built Environment:

Designing buildings that maximize wind harvest and drive a set of turbines that provide power for buildings is the architectural concept presented in this scientific analysis. The practicalities presented in this design concept will interest engineers and architects, while the possibilities of wind power being used at a domestic level will delight proponents of renewable energy.

Sander Mertens is a professor at the Technical University of Delft, whose wind energy research program is preeminent in Europe.

Summary

iii

List of Symbols

vii

Introduction

1

(2)

Basic Theory

3

(15)

Drag-driven rotor versus lift-driven rotor

3

(4)

Drag-driven wind turbines

3

(1)

Lift-driven wind turbines

4

(2)

Hybrid-driven wind turbines

6

(1)

Comparison of the wind turbines

7

(1)

Constraints

7

(6)

Built environment

8

(2)

Wind turbine

10

(2)

Building

12

(1)

The Building-Augmented Wind Turbine

13

(1)

The twisted H-Darrieus wind turbine

14

(4)

Wind Characteristics

18

(26)

Global wind in the built environment

18

(5)

Log-law

18

(4)

Step in roughness height

22

(1)

Turbulence

23

(1)

Local wind in the built environment

23

(9)

Building characterization

23

(2)

Flow characterization

25

(3)

Wind speed probability distribution

28

(4)

Wind at buildings

32

(12)

Stagnation point

32

(1)

Separation

33

(1)

Wake and recirculation zone models

34

(5)

Reattachment distance

39

(1)

The cavity model

39

(3)

Influencing the separation velocity and backpressure

42

(2)

Analysis Tools

44

(21)

Mathematical

44

(3)

Potential flow

44

(1)

Vortex sheets

45

(2)

Momentum theorem

47

(1)

Experimental

47

(6)

The open jet wind tunnel

47

(1)

Tunnel correction

48

(2)

Error in power coefficient from measurements

50

(1)

Scaling rules

51

(1)

Wind turbine power

51

(2)

Computational Fluid Dynamics

53

(12)

The turbulence model

53

(4)

Near-wall region

57

(1)

The grid

58

(1)

The atmospheric boundary layer

59

(1)

Some initial verifications

60

(5)

Wind Turbines Close to Buildings

65

(31)

The wind turbine's performance close to a building

65

(7)

Performance in partly accelerated flow

65

(5)

The acceleration at the roof

70

(2)

The lift-driven HAWT in skewed flow

72

(2)

The H-Darrieus in skewed flow

74

(17)

Induction factor at small load

74

(5)

Induction factor at high load

79

(3)

Power coefficient

82

(3)

Performance

85

(1)

Verification of the model

86

(2)

Discussion on the validity of the model

88

(3)

The energy yield at the roof

91

(2)

The energy yield at the sides of a building

93

(3)

Wind Turbines Between Airfoil-Shaped Buildings

96

(28)

Momentum Theory

98

(5)

Shrouded wind turbine

99

(2)

Diffuser-augmented wind turbine

101

(2)

2D Vortex model for a shrouded rotor

103

(12)

Set-up of the model

104

(2)

Induced velocities

106

(1)

Resulting velocities

107

(2)

Power coefficient

109

(1)

Verification of the model

109

(4)

Discussion on the validity of the model

113

(2)

Application of vortex model results to momentum theory

115

(1)

Finite aspect ratio effects

115

(1)

The ducted small wind turbine

116

(3)

Allowed stream tube size

117

(1)

Velocity between the 1/4-chord points

118

(1)

The shrouded H-Darrieus

119

(1)

Yawed and opposite flow

119

(3)

Yawed flow

120

(1)

Opposite flow

121

(1)

Zero power output

122

(1)

The energy yield of the shrouded rotor

122

(2)

Wind Turbines in Ducts Through Buildings

124

(15)

The plate concentrator model

124

(4)

Power coefficient

125

(1)

Jet contraction

126

(2)

Verification of the plate concentrator model

128

(5)

Verification of the jet velocity

128

(1)

Verification of the jet contraction

129

(1)

Verification of the pressure drop across the actuator

130

(2)

Verification of the power coefficient

132

(1)

Approximated plate concentrator model

133

(1)

Discussion on the validity of the model

134

(1)

Yawed flow

134

(1)

The energy yield of a plate concentrator

135

(1)

Energy yield of a combined plate concentrator

136

(3)

Results and Conclusions

139

(8)

Summary of results for general use

139

(2)

Summary of results for wind energy in the built environment

141

(4)

Integration of wind turbine and building

141

(1)

Energy yield examples of Building-Augmented Wind Turbines

142

(2)

Wind Turbines for the built environment

144

(1)

Expectations

145

(2)

Expectations for wind energy in the built environment

145

(1)

Research on aerodynamics of Building-Augmented Wind Turbines

145

(2)

References

147

(22)

Appendices

Appendix A Stream tube length in viscous flow

152

(2)

Appendix B Measurements plate concentrator

154

(1)

Appendix C Used turbulence models CFD calculations

155

(1)

Appendix D Data high-lift cambered airfoil Da2-1999

156

(1)

Appendix E Induced velocities by a wake

157

(2)

Appendix F Prony brake

159

(2)

Appendix G Triangular chord-wise vortex distribution

161

(5)

Appendix H Suitable turbulence model for calculation of flow around airfoil

166

(1)

Appendix I Calculated lift- and drag coefficient data for a NACA 0018 airfoil

167

(2)

Appendix J Quick siting guideline

169

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Wind Energy In The Built Environment: Concentrator Effects of Buildings

Summary

Author Biography

Table of Contents

Supplemental Materials

FREE SHIPPING

Rent More, Save More! Use code: BBRENTAL

5% off 1 book, 7% off 2 books, 10% off 3+ books

Wind Energy In The Built Environment: Concentrator Effects of Buildings

Summary

Author Biography

Table of Contents

Supplemental Materials

Digital License