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CONTENTS
Volume 40, Number 5, May 2025 (Special Issue)
 

Abstract
This study presents a series of innovative modifications to the traditional Savonius-Wind-Turbine (SWT) design, aiming to boost its performance for utilization in metropolitan areas with low wind speeds. The advancements include five key parts: (i) Integration of an Airfoil Enclosure System (AES) around the rotor to prevent wind interference with the returning blades and to accelerate airflow. (ii) Assessing the effects of gaps within the AES. (iii) Developing a new airfoil-shaped blade profile that harnesses lift and drag forces simultaneously. (iv) Implementation of a big shaft within the novel rotors to allow for the generator's installation and evaluation of its effect. (v) Investigation of the optimum vertical gap in the AES. The result of these enhancements demonstrated a remarkable increase in efficiency (CP=0.3) by a factor of 2.3 versus the conventional/traditional SWT design (CP=0.13). This significant improvement was achieved with a three-bladed rotor featuring a novel airfoil-shaped blade profile, a 60 mm rotor shaft, and the AES containing a 100 mm vertical gap.

Key Words
Airfoil Enclosure System (AES); Computational Fluid Dynamics (CFD); Large Eddy Simulations (LES); Savonius Wind Turbine; Vertical Axis Wind Turbine (VAWT)

Address
Daniel Gemayel:Civil Engineering Department, Toronto Metropolitan University, 350 Victoria, St. M5B 2K3, Toronto, Canada

Athanasios Verros:Civil Engineering Department, Toronto Metropolitan University, 350 Victoria, St. M5B 2K3, Toronto, Canada

Mohamed Abdelwahab:Civil Engineering Department, Toronto Metropolitan University, 350 Victoria, St. M5B 2K3, Toronto, Canada

Haitham Aboshosha:Civil Engineering Department, Toronto Metropolitan University, 350 Victoria, St. M5B 2K3, Toronto, Canada

Abstract
The uncertainty of climate-related challenges, including cold climates, wildfires, flooding, and high winds, is increasing throughout Canada due to the escalating effects of climate change. Therefore, climate data is a crucial source of information for a wide range of activities, from agriculture and transportation to infrastructure design and disaster preparation. In remote regions throughout Canada, accessibility and reliability of weather data can become a critical factor for the sustainability and well-being of Indigenous communities. Thus, this study investigates weather station reliability and correlates it with the geographical locations of case-specific Indigenous communities. The study first analyzes a specific geographical distribution of Indigenous communities and proximate weather stations in northern Manitoba and Ontario. The study then assessed the quality of the historical wind data using an extreme value analysis and return period for the peak wind velocities. While some regions throughout Canada have a robust network of weather stations and data, others lack acceptable coverage. Therefore, this analysis identifies the weather station reliability from the provided wind data based on the longevity and quality of the provided data. Reliability conducted in the study refers to the quality of the weather data and geographical proximity and relevance of weather stations to Indigenous communities. Wind records revealed significant differences in peak wind velocities at the stations surrounding the Bunibonibee Cree Nation due to the geographical distance and terrain. Wind record lengths also allowed for forecasting peak wind gusts, with outcomes showing increases and decreases based on historical data. Accumulating more wind records tended to stabilize fluctuations in peak wind gusts. By improving the accessibility and quality of climate data in these areas, we can better support Indigenous communities in their efforts to adapt to a changing climate and manage their resources sustainably.

Key Words
extreme value analysis; indigenous communities; mean wind velocity; return period; weather station reliability

Address
Tristen Brown:Department of Civil Engineering, Lakehead University, 955 Oliver Rd, Thunder Bay, ON P7B 5E1, Thunder Bay, Canada

Ahmed Elshaer:Department of Civil Engineering, Lakehead University, 955 Oliver Rd, Thunder Bay, ON P7B 5E1, Thunder Bay, Canada

Anas Issa:Department of Civil Engineering, United Arab Emirates University, United Arab Emirates, Abu Dhabi

Abstract
The global expansion of wind energy capacity, as reported by the International Energy Agency, has led to a significant rise in wind turbine farm installations. Most of the wind turbines, approximately 93%, are situated onshore, primarily in rural areas. This onshore placement exposes them to a heightened risk of encountering High-Intensity Wind events (HIW), including tornadoes. Tornadoes, due to their unpredictable and localized nature, present a formidable challenge for ensuring the structural integrity of onshore wind turbines. Remarkably, design guidelines for onshore wind turbines, such as the International Electrotechnical Commission (IEC) 61400-1, do not incorporate tornado wind loads. This study endeavors to fill the void by developing a numerical code to assess the structural response of three-blade onshore wind turbines subjected to 3D tornado wind loads, with a specific focus on the influence of the angle of twist. This research exclusively examines F2 tornado wind fields. The research methodology involves an extensive parametric study aimed at identifying critical F2 tornado configurations that induce maximum straining actions on both wind turbine blades and the supporting tower. Additionally, the study explores the optimal blade pitch angle that can mitigate the impact of these tornado-induced loadings. Three distinct wind turbines are analyzed, each with power capacities of 1.5MW, 5.0MW, and 10.0MW, respectively. The result shows that setting the blade pitch angle as 90 degrees could minimize the strain actions on the blade roots and the resultant bending moment at the tower base. With the presence of angle of twist, the resulted bending moments will be increased by 1% to 3% for all wind turbines considered in the current study. A comparison of the above findings with the design load cases given in IEC guidelines revealed that the flap-wise bending moments induced by F2 tornado wind loads exceed those calculated using standard design load cases for the wind turbines considered in this study.

Key Words
angle of twist; blade pitch angle; parametric study; tornado; wind turbine

Address
Shaoqing Yu:Department of Civil and Environmental Engineering, Western University, London ON N6A 5B9, Canada

Ashraf El Damatty:1) Department of Civil and Environmental Engineering, Western University, London ON N6A 5B9, Canada
2)Department of Construction Engineering, The American University in Cairo, Cairo 11835, Egypt

Abstract
With the growth of mankind's demand for green energy, it is frequently reported that the vortex-induced vibration of the wind turbine tower (WTT) may occur under the self-supporting state during construction. In order to ensure the normal construction and structural safety of the wind turbine, it is necessary to study the vortex-induced vibration (VIV) of the turbine tower under the self-supporting state. Most of theoretical studies on VIV of the column are built based on numerical simulation results or displacement identification of wind tunnel tests, which leads to the existing theories cannot accurately predict the VIV characteristics. In order to accurately predict the VIV characteristics of the WTT under the self-supporting state, the spring suspended sectional model and the force and vibration synchronous measurement with built-in balances were employed in experimental simulation of the WTT's VIV. The results indicate that Reynolds number effect can be effectively corrected by increasing the surface roughness. The vibration measurement method with a sectional model successfully simulates the WTT's VIV, and the built-in balance technique successfully identifies the nonlinear vortex-induced force. The vortex-induced force calculated based on the existing empirical models are deviate greatly from the experimental test results, which indicate the empirical modes may overestimate or underestimate the VIV response. Increasing damping can effectively suppress the WTT's VIV, and the amplitude varies almost linearly with the damping ratio.

Key Words
Reynolds number effect; vortex-induced force; vortex-induced vibration; wind tunnel test; wind turbine tower

Address
Qi Zhou:1)Department of Civil Engineering and Smart Cities, Shantou University, Shantou, Guangdong, China
2)Department of Civil and Environmental Engineering, Western University, London, Ontario, Canada

Ke Li:Department of Civil Engineering and Smart Cities, Shantou University, Shantou, Guangdong, China

Zhou Xu:Department of Civil Engineering and Smart Cities, Shantou University, Shantou, Guangdong, China

Ashraf El Damatty:Department of Civil and Environmental Engineering, Western University, London, Ontario, Canada

Abstract
This paper introduces a framework designed to estimate post-hurricane disaster housing needs to enhance community resilience by streamlining the recovery process and facilitating logistics planning for emergency management agencies. The modeling approach commences with defining the study domain using housing data sourced from the National Structure Inventory and demographic information from the US Census, organized by Census Tracts. Next, a full-track hurricane impacting the study domain is selected from either a catalog of historical or simulated events. The peak wind speed at each Census Tract during the hurricane's passage is then calculated using a parametric wind field model. Building fragility curves and loss functions obtained from the FEMA HAZUS program are utilized to assess damages and losses to single-family residential dwellings, multi-family apartments, and multi-unit hospitality buildings. Demographic and socio-economic factors such as income, age, and insurance coverage combined with the estimated direct building losses are used to predict the number of short term and long-term displaced households. As part of the modeling framework validation study, the predicted numbers of long term displaced households for four prior hurricane events are compared and calibrated against the actual numbers of direct housing assistance or maximum amount of individual assistance grants provided by FEMA. While the total number of long-term displaced households predicted by the model does not align precisely with the actual assistance provided by FEMA, it was found that the model-predicted long-term displaced households by ZIP codes exhibit a high correlation with FEMA assistance figures. On average, FEMA extended assistance to approximately 20-60% of the model-predicted long-term displaced households. Discrepancies are attributed partly to factors such as eligibility requirements for FEMA assistance and availability of governmental funding, which are not accounted for in the current model.

Key Words
community resilience; displaced households; fragility curve; hurricane; disaster housing; logistics planning; loss function; residential buildings

Address
Adish D. Shakya:Glenn Department of Civil Engineering, Clemson University, Clemson, South Carolina 29634, USA

Susmita Bhowmik:Glenn Department of Civil Engineering, Clemson University, Clemson, South Carolina 29634, USA

Weichiang Pang:Glenn Department of Civil Engineering, Clemson University, Clemson, South Carolina 29634, USA

Michael W. Stoner:Glenn Department of Civil Engineering, Clemson University, Clemson, South Carolina 29634, USA

Yongjia Song:Industrial Engineering, Clemson University, Clemson, South Carolina 29634, USA

Dustin Albright:School of Architecture, Clemson University, Clemson, South Carolina 29634, USA

David Vaughn:Glenn Department of Civil Engineering, Clemson University, Clemson, South Carolina 29634, USA

Abstract
When using the wind tunnel procedure, the ASCE 7 and NBCC 2020 suggest additional testing to determine the impact on wind loads when specific influential buildings are removed. The unsheltered test configuration informs the lower limit of the design wind loads. For example, loads based on the wind tunnel test are not to be less than 80% of the analytical prediction based on ASCE 7, but an unsheltered configuration can justify reducing the lower limit to 50%. Determining the influential sheltering building requires engineering experience and judgement and is inevitably subjective. The absence of an influential building usually results in the proposed building being more exposed to higher wind loads. The removal of the influential building creates an arbitrary case that assumes it would be demolished and not replaced during the design working life of the proposed building. Removing multiple influential buildings simultaneously is more onerous and even less likely. Therefore, this study uses building service life datasets for many high-rise buildings to develop a probabilistic model of the removal scenario. This model combines wind tunnel test data to examine the effect of the service life of the influential buildings on the determined design wind loads in the unsheltered configuration. The results provide insights into designing and determining the unsheltered wind tunnel test configuration and recommend lower limits based on the unsheltered wind tunnel test configurations.

Key Words
design working life; future condition; probability model; unsheltered; wind loads

Address
Si Han Li:Rowan Williams Davies & Irwin Inc., Guelph, ON., Canada

John Kilpatrick:Rowan Williams Davies & Irwin Inc., Guelph, ON., Canada

Jason Garber:Rowan Williams Davies & Irwin Inc., Guelph, ON., Canada

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