Wind Energy Exploitation in Urban Environment: TUrbWind 2018 Colloquium (Research Topics in Wind Energy Book 8)

This book presents numerical and experimental research in the field of wind energy exploitation in urban environments. It comprises a selection of the best papers from the international colloquium “Research and Innovation on Wind Energy Exploitation in Urban Environment” (TUrbWind), held in Riva del Garda, Italy in September 2018. The book includes contributions from different research fields in urban wind resources, wind energy conversion systems, and urban integration, mainly focusing on the following topics: · turbine concepts for urban and sub-urban environment; · measuring and modelling wind resource; · rotor aerodynamics, wakes and noise; · design, loads, and supporting structures; · novel shapes and materials; · building concepts for wind energy exploitation; · planning approaches for wind exploitation in urban areas. It is a valuable resource for researchers and practitioners interested in the integration of wind energy systems and turbines in urban areas. Preface 6 Contents 7 A Preliminary Assessment of the Impact of Gurney Flaps on the Aerodynamic Performance Augmentation of Darrieus Wind Turbines 9 1 Introduction 11 1.1 Background 11 1.2 Motivation 12 2 Methodology 13 2.1 Case Study 13 2.2 Numerical CFD Approach 15 3 Results 18 3.1 Assessment of GF Effect on Static Polars 18 3.2 Sensitivity Analysis on the GF Configuration 19 3.3 Sensitivity Analysis on the GF Height 20 3.4 Sensitivity Analysis on TSR and Power Curves Prediction 22 4 Conclusions 25 References 26 Experimental Characterization of VAWT Airfoils Under Turbulent Flows 28 1 Introduction 29 2 Methodology 30 2.1 Wind Tunnel Settings 30 2.2 Turbine Prototype 33 2.3 Airfoil Model 34 2.4 Data Analysis 35 3 Results 37 3.1 Turbine Power Curves 37 3.2 Airfoil Measurements 38 3.3 VAWT Performance Prediction Using Single Streamtube Model 42 4 Conclusions 43 4.1 Future Developments 44 References 44 Numerical Simulation and Measurement for Location Optimization of a Vertical Axis Wind Turbine (VAWT) 46 1 Introduction 46 2 Additive Manufacturing and Model Validation 48 2.1 Design Workflow 49 2.2 Mathematical Model and Numerical Simulation 50 2.3 Design Generation and Boundary Conditions 52 2.4 Discretization of Physical Domain 53 2.5 Numerical Results 54 3 Low Speed Wind Tunnel Experiments 56 3.1 Validation of Airfoil Flow Field 58 4 Conclusions and Outlook 60 References 60 The Effect of Tail Fin Size on the Yaw Performance of Small Wind Turbines Operating in Unsteady Flow 62 1 Introduction 62 2 Tail Fin Theory 65 2.1 Unsteady Slender Body Theory 65 2.2 Approximation Method 66 2.3 Experimental Estimation 67 2.4 Relative Motion of the Tail Fin 67 2.5 Wake Velocity 68 2.6 Unsteady Wind Term 69 3 Experimental Work 69 4 Comparison Between Measurements and Yaw Modelling Theory 71 4.1 Large Tail Fin Simulations 72 4.2 Small Tail Fin Simulations 75 5 Discussion and Conclusions 76 References 76 Installation of a Small Building-Mounted Wind Turbine: A Case Study from Idea to Implementation 78 1 Introduction 78 2 Feasibility Study for the South Tower 79 2.1 Micro-siting 81 2.2 Stability Assessment 82 2.3 Environmental Concerns 84 2.4 Economic Viability 90 2.5 Building Permit and Future Installation 93 2.6 Summary of the Approach 94 3 Conclusions 94 References 95 Evaluation of the Causes of Vibration and Oscillation in a Vertical Axis Small Wind Turbine (VASWT) and Its Reduction 96 1 Introduction 96 1.1 Scientific Issue 97 1.2 Aim of Work 98 1.3 Method 99 2 Vibration and Oscillation of Small Wind Turbines 99 2.1 Natural Frequencies 100 2.2 Excitation Frequencies 100 3 Measurement Concept 101 3.1 Measurement Set-Up 102 4 Results 104 4.1 Measurement Without Decoupling Element 104 4.2 Measurement Results with Decoupling 109 5 Discussion 110 5.1 Range of Oscillation and Vibration in VASWTs 111 5.2 Influence on the Immediate Environment 112 5.3 Effectiveness of Decoupling Elements 112 6 Conclusion 113 References 113 Assessment of the Impact of a Low-Rise Flat Roofed Building on Ambient Wind Conditions 115 1 Introduction 116 2 Measurement Set-Up 116 2.1 Lichtenegg Energy Research Park 116 2.2 Set-Up 117 3 Measuring Execution 119 3.1 Data Basis 119 3.2 Binning 119 4 Results 121 4.1 Horizontal Wind Speeds 121 4.2 Vertical Wind Speeds 124 4.3 Horizontal Turbulence Intensity 127 4.4 Vertical Turbulence Intensity 131 5 Conclusion 132 References 133 A Detailed Analysis of the Centrifugal Pumping Phenomenon in HAWTs Through the Use of CFD Models 135 1 Introduction 135 2 Numerical Models 138 2.1 CFD 3D Rotor Model 138 2.2 CFD 3D Fixed Blade Model 139 3 Results and Discussions 142 3.1 2D–3D Aerodynamic Coefficient Comparison 142 3.2 2D–3D Post-processing Analysis 144 3.3 Force Analysis in the Separated Layer 148 3.4 Fixed Blade Simulation Results 151 4 Conclusions 153 References 154 Measuring the Torque and Thrust Loading on the Blades of a Small Horizontal Axis Wind Turbine Operating in Highly Turbulent Flow Regimes 156 1 Introduction 156 2 Blade Loads 158 3 Instrumentation and Data Acquisition 159 4 Blade Load Hub System 160 5 Blade Load Hub System 164 6 Discussion and Conclusions 168 References 169 Dynamic Identification of a Vertical Axis Wind Turbine 170 1 Introduction 170 2 Experimental Facility 171 3 Wind Field and Power Production 174 4 Structural Response 175 5 Conclusions and Perspectives 180 References 180 Experimental Assessment of an Actuator-Line Simulation Tool for VAWTs 181 1 Introduction 183 2 Wind Tunnel Tests 184 3 CFD Model 185 3.1 ACL Code 185 3.2 Construction of Polar Data 187 3.3 Sub-models 190 4 Results 192 4.1 Rotor Aerodynamics and Performance 193 4.2 Wake Analysis 198 5 Conclusions 202 References 203 Wind Regimes in Urban Environments: Experimental Comparison with the IEC 61400.2-2013 Open Terrain Wind Model 205 1 Introduction 205 2 Methodology 207 2.1 Aerogenesis 5 KW Wind Turbine 207 2.2 Wind Resource Assessment 207 2.3 Normal Turbulence Model 210 3 Results and Discussions 211 3.1 IEC Wind Model and Comparison with the Callaghan Site Data 211 3.2 Vertical Component of Wind Velocity 211 4 Conclusions 216 References 217 Structural Optimisation of 3D Printed Small Diffuser Augmented Wind Turbine Blade Using Bi-directional Evolutionary Layout Optimisation Method 219 1 Introduction 219 2 Method 222 2.1 Modelling Overview 222 2.2 BELO Optimisation 223 3 PET-G Material Properties 224 3.1 Three-Point Bending Test 224 3.2 Blade Tip Deflection Test 226 4 Optimisation Results 228 5 Summary and Conclusions 230 References 231 Experimental Investigation of the Aerodynamic Interaction Between Ducts and Actuator Discs 233 1 Introduction 234 2 The DWT Momentum Theory 235 3 Experimental Setup 238 3.1 Wind Tunnel Description 238 3.2 Aerofoil Model and Screen Model 238 3.3 Measurement Techniques 239 4 Results and Discussion 240 4.1 Thrust Measurement 240 4.2 The Velocity Fields of the Empty Duct and the Duct with Screen 243 4.3 Pressure Distributions Along the Duct 245 5 Conclusions 247 References 248 Analyzing the Unsteady Dynamic Behaviour of a Small Wind Turbine for Urban Applications 249 1 Introduction 250 2 Methods 251 2.1 Experimental Tests 251 2.2 Numerical Modeling 252 3 Results 254 4 Conclusions 257 References 258 Effectiveness of Wind Turbines in Urban Environment 259 1 Introduction 261 2 Methodology and Data Processing 262 3 Results and Discussion 264 3.1 Wind Statistics on Wind Speed Magnitude 264 3.2 Wind Statistics on Wind Speed Direction 265 3.3 Energy Exploitation Under Wind Speed Gusts 268 3.4 Energy Exploitation Under Wind Direction Variation 270 4 Conclusions 272 References 273 Front Matter ....Pages i-viii A Preliminary Assessment of the Impact of Gurney Flaps on the Aerodynamic Performance Augmentation of Darrieus Wind Turbines (Daniele Di Rosa, Francesco Balduzzi, Alessandro Bianchini)....Pages 1-19 Experimental Characterization of VAWT Airfoils Under Turbulent Flows (Andreu Carbó Molina, Sander Van de Maele, Gianni Bartoli, Tim De Troyer, Mark Runacres)....Pages 21-38 Numerical Simulation and Measurement for Location Optimization of a Vertical Axis Wind Turbine (VAWT) (Giuseppe Ruffino, Susan Schaar, Daniel Lehser-Pfeffermann, Danjana Theis, Frank Ulrich Rückert, Tobias Müller et al.)....Pages 39-54 The Effect of Tail Fin Size on the Yaw Performance of Small Wind Turbines Operating in Unsteady Flow (David Bradney, Samuel Evans, Philip Clausen)....Pages 55-70 Installation of a Small Building-Mounted Wind Turbine: A Case Study from Idea to Implementation (Quentin Deltenre, Mark C. Runacres)....Pages 71-88 Evaluation of the Causes of Vibration and Oscillation in a Vertical Axis Small Wind Turbine (VASWT) and Its Reduction (Alexander Hirschl, Mauro Peppoloni, Kurt Leonhartsberger)....Pages 89-107 Assessment of the Impact of a Low-Rise Flat Roofed Building on Ambient Wind Conditions (Stefan Hübl, Mauro Peppoloni, Kurt Leonhartsberger, Alexander Hirschl)....Pages 109-128 A Detailed Analysis of the Centrifugal Pumping Phenomenon in HAWTs Through the Use of CFD Models (Stefano Mauro, Rosario Lanzafame, Michele Messina, Sebastian Brusca)....Pages 129-149 Measuring the Torque and Thrust Loading on the Blades of a Small Horizontal Axis Wind Turbine Operating in Highly Turbulent Flow Regimes (Shaun M. Nay, Philip D. Clausen)....Pages 151-164 Dynamic Identification of a Vertical Axis Wind Turbine (Luisa Pagnini, Giuseppe Piccardo, Maria Pia Repetto, Giuseppe Riotto)....Pages 165-175 Experimental Assessment of an Actuator-Line Simulation Tool for VAWTs (Pier Francesco Melani, Paolo Schito, Giacomo Persico)....Pages 177-200 Wind Regimes in Urban Environments: Experimental Comparison with the IEC 61400.2-2013 Open Terrain Wind Model (Muhammad Iftekharul Rakib, Shaun Nay, Samuel Evans, Philip Clausen)....Pages 201-214 Structural Optimisation of 3D Printed Small Diffuser Augmented Wind Turbine Blade Using Bi-directional Evolutionary Layout Optimisation Method (Mariana S. P. da Costa, Joss Kesby, Philip D. Clausen)....Pages 215-228 Experimental Investigation of the Aerodynamic Interaction Between Ducts and Actuator Discs (J. Tang, G. J. W. van Bussel)....Pages 229-244 Analyzing the Unsteady Dynamic Behaviour of a Small Wind Turbine for Urban Applications (Francesco Castellani, Francesco Berno, Matteo Becchetti, Davide Astolfi, Emanuele Piccioni)....Pages 245-254 Effectiveness of Wind Turbines in Urban Environment (L. Battisti, S. Dell’Anna, M. Raciti Castelli, A. Brighenti)....Pages 255-269