Other Civil and Environmental Engineering Commons^™

Effects Of Wind Turbine Rotor Positioning On Tornado Induced Loads, Juan P. Lopez Ortiz

Electronic Thesis and Dissertation Repository

This study investigates the loads induced by a large-scale tornado simulation on a horizontal axis wind turbine (HAWT) to assess the influence of three-dimensional flows with respect to the HAWT position. The loads were analyzed under two rotor operational conditions, idling and parked, at five radial distances. Subsequently, experimental validation of the numerical code HIW-TUR was conducted by evaluating the induced moments for various yaw and pitch angles. The experimental results demonstrated that the bending moment was the most important in terms of magnitude and variation with respect to the HAWT position. Furthermore, The HIW-TUR code accurately identified the magnitude …

Erosion Control Of Steep Open Channels Using Articulated Concrete Blocks, Mohammadomid Marandi

Electronic Thesis and Dissertation Repository

Overtopping flow can undermine the stability of hydraulic structures including embankments and spillways through the shear stress and the subsequent soil erosion. Increased flow velocity can cause scour, which can result in the failure of dams, bridges, and overall open channel hydraulic structures. Sediment transport is another crucial issue in open channels that can cause severe socioeconomic and environmental consequences. Two general approaches are commonly considered for scour prevention. The first approach involves flow modifications to minimize the corresponding effects on the structures. The second approach is associated with bed armoring and placing physical barriers on the natural bedding such …

Implication Of City Growth On Wind-Induced Loads For Cladding And Structural Design, Hadil M. Abdallah

Electronic Thesis and Dissertation Repository

As cities grow, the urban topology changes in density resulting in continuous variations in wind flow. The interaction of flow with this changing surrounding environment drives the aerodynamics to become more complex and varying, subjecting the building to significant changes in wind-induced-loads both on structural and non-structural elements. In this study, a series of boundary layer wind tunnel tests are conducted to investigate the impact of city growth on cladding and structural loading by using a typical tall building adopted from the Commonwealth Advisory Aeronautical Council (CAARC) building model. The city growth is represented by five different generic surrounding configurations, …

Flow Visualization Study Of Wake-Stabilized Diffusion Flames In A Crossflow: Effects Of Crossflow Turbulence, Diya Cui

Electronic Thesis and Dissertation Repository

Effects of crosswind turbulence on the mechanisms and flow structures affecting emissions from non-premixed wake stabilized flames from elevated stacks are investigated. In the current work, two conditions of upstream crossflow are tested to investigate the effects of turbulence on the flame, including the turbulent flow with enhanced freestream turbulence that is generated by a passive grid placed upstream of the burner, and smooth flow with ambient turbulence for baseline comparisons. The experimental method of Mie scattering flow visualization is used to investigate the effects of turbulence. The addition of freestream turbulence has been found to make changes to the …

Experimental Study Of Tornado-Induced Pressures, Aya Kassab

Electronic Thesis and Dissertation Repository

The increased devastation associated with tornadic flow-fields in terms of human lives or destruction of properties and their subsequent economic losses highlights the significance of understanding the tornado vortex structure, particularly near the ground where the majority of this destruction happens. While the body of research in this area is increasing there is a lack of resolution associated with physical near-surface measurements in tornado-like vortices (TLVs) and the effects of translation, surface roughness, and surface vortex dynamics are not yet well understood.

In order to address these gaps, high spatial and temporal surface pressure measurements were carried out at WindEEE …

New Experimental Methods For Modelling Canopy Problems, Marilena Enus

Electronic Thesis and Dissertation Repository

The challenge in large scale experimental fluid dynamics comes from the demand to develop simple methods that can measure and model movement of flexible objects and wind flow over large three-dimensional volumes with readily available equipment. Representing and modelling the flow around trees is challenging mainly because of the complexity and variability of trees. In this research different methods were tested in the novel Wind Engineering Energy and Environment (WindEEE) Dome facility at Western University, Canada to capture displacements of a moving single tree and flow velocities over a model forest edge in a three-dimensional form. The tested measuring methods …

Effect Of The C-Source And Cod/N On Nitrite And Partial Nitrate Denitrification, Ahmed Fathy Elyas Badia

Electronic Thesis and Dissertation Repository

The main objectives of this study were: (i) to investigate dynamic specific denitrification rates (SDNR) from nitrite at various chemical oxygen demand (COD) / nitrogen (N) ratios using municipal wastewater (MWW) and acetate, and to study the kinetic parameters, (ii) to investigate the dynamic specific denitrification rates (SDNRs) from nitrite at various COD/N ratios in a system that uses methanol as a complementary carbon source, and studying the effect in case if nitrate replaced nitrite, and (iii) to investigate and compare between the nitrite shunt and N-PDN-anammox technologies through studying the dynamic specific denitrification rates (SDNRs) from nitrate and nitrite …

Machine Learning Prediction Of Mechanical And Durability Properties Of Recycled Aggregates Concrete, Itzel Rosalia Nunez Vargas

Electronic Thesis and Dissertation Repository

Whilst recycled aggregate (RA) can alleviate the environmental footprint of concrete production and the landfilling of colossal amounts of demolition waste, there need for robust predictive tools for its effects on mechanical and durability properties. In this thesis, state-of-the-art machine learning (ML) models were deployed to predict properties of recycled aggregate concrete (RAC). A systematic review was performed to analyze pertinent ML techniques previously applied in the concrete technology field. Accordingly, three different ML methods were selected to determine the compressive strength of RAC and perform mixture proportioning optimization. Furthermore, a gradient boosting regression tree was used to study the …

Comparative Assessment Of Downscaling Methods And Application Towards Analysis Of Climate Change Impact On Urban Regions, Markus Eichenbaum

Electronic Thesis and Dissertation Repository

Global climate models (GCM) are sophisticated numerical models used to make long term climate projections. However, the resolution of their output is too coarse for climate change related local impact studies on urban regional scales. Downscaling efforts are taken to address this and increase GCM projection resolution. Physical Scaling (SP) downscaling methodology attempts to incorporate the physical basis of dynamical downscaling efforts with the computational efficiency of statistical methods. In this study, North American Regional Reanalysis surface skin temperature and precipitation data for a 1°x1° region centered on Houston, TX are downscaled to a resolution of 500m via SP and …

Future Changes Of Hydroclimatic Extremes In Western North America Using A Large Ensemble: The Role Of Internal Variability, Mohammad Hasan Mahmoudi

Electronic Thesis and Dissertation Repository

Increases in the intensity and frequency of extreme events in Western North America (WNA) can cause significant socioeconomic problems and threaten existing infrastructure. In this study we analyze the impacts of climate change on hydroclimatic extremes and assess the role of internal variability over WNA, which collectively drain an area of about 1 million km². We used gridded observations and downscaled precipitation, maximum and minimum temperature from seven General Circulation Models (GCMs) that participated in the Coupled Model Intercomparison Project Phase 5 (CMIP5) and a large ensemble of CanESM2 model simulations (CanESM2-LE; 50 members) for this analysis. Spatial …

Commercial Water Claims: City Of London Assessment Of Claims Made By London Residents, Jonathan Abbruzzese, Yousir Aldin, Christine Eagles, Karen Lemon, Alexander Watson

Community Engaged Learning Final Projects

The City of London has a mandate to provide its residents with high grade water and yet there have been complaints concerning the impurities, otherwise known as residuals, and the overall quality. This paper delves into the truth about the contents of the municipal water system and what the effects of its components are to the London populace. A public survey asked residents questions about their concerns and water drinking habits. The survey pointed to concerns about fluoride, residual chlorine and overall taste of water among others. Fluoride is known to reduce tooth decay (CDC, 2018) and any negative consequences …

Electroflotation For Treatment Of Paint Wastewater: Experiments, Kinetics And Hydrodynamics, Syed Reza Mohtashami

Electronic Thesis and Dissertation Repository

Electroflotation (EF) is a process used to remove suspended particles from water using the gas bubbles generated from the water electrolysis. This dissertation focuses on the fundamental principles and applications of EF in the treatment of industrial wastewaters, and in particular, treatment of automotive paint wastewater. In the first part, an extensive review of applications of electroflotation in the treatment of different categories of industrial wastewaters, including the fundamentals of the process, electrode materials, design aspects and process variables, is conducted. The second part is focusing on the kinetic study, statistical analysis and empirical modeling of available experimental data from …

Modeling Of Suspended Sediment Concentration Using Conventional And Machine Learning Approaches, In Thames River, Canada, Issam Mohamed

Electronic Thesis and Dissertation Repository

Water resource management, planning, hydraulic design, environmental conservation, reservoir management and operation all require reliable information and data about Suspended Sediment Concentration (SSC). To predict such data, direct sampling and Sediment Rating Curves (SRC) are commonly utilized. Since direct sampling can be risky during extreme weather events and SRC cannot provide satisfactorily dependable results, engineers are trying to propose new precise fore-casting approaches. Various soft computing techniques have been applied to model different hydrological and environmental problems and have showed promising results in this regard. Although many studies have been performed to simulate the phenomena of SSC at numerous rivers …

Modelling Of Future Flood Risk Across Canada Under Climate Change, Ayushi Gaur

Electronic Thesis and Dissertation Repository

Climate change has induced changes in key climate variables and hydrological cycle in Canada. In this study, future runoff projections made by 21 GCMs following four Representative Concentration Pathways (RCPs) are used as inputs into a macro-scaled hydrodynamic model: CaMa-Flood to simulate 25 km resolution daily streamflow across Canada for historical (1961-2005) and future (2061-2100) time-periods. Future changes in flood-hazard as a consequence of changes in flooding frequencies of historical 100-year and 250-year return period flood events, and changes in the month of occurrence of extreme flows are analyzed. Changes in flood risk at Canada’s 100 most populous cities and …

Full-Scale And Wind Tunnel Investigation Of The Flow Field Over A Coastal Escarpment, Julien Lotufo

Electronic Thesis and Dissertation Repository

A multiscale experimental approach, consisting of full-scale measurements and physical modeling in a laboratory environment, was conducted to investigate the flow field over a coastal escarpment on the Wind Energy Institute of Canada’s research and development wind park. The influence of sea breeze inflow conditions, thermal stability and local topographic features on the flow field were examined.

The results of the full-scale study show that the near surface flow field is significantly influenced by the sea breeze circulatory coastal flow regime, creating larger shear layers with a smaller recirculation regions compared to cases of typical boundary layer flow typical boundary …

Microbial Repopulation Following In Situ Star Remediation, Gavin Overbeeke

Electronic Thesis and Dissertation Repository

In situ STAR (Self-sustaining Treatment for Active Remediation) is an emerging remediation technology which uses smouldering combustion to destroy nonaqueous phase liquid (NAPL) contamination in the subsurface. Since STAR smouldering travels through contaminated soils slowly (~0.5 to 5 m/day) and subjects them to high temperatures (400–1000°C), it is expected that this technology will thoroughly dry and sterilize the zones which it treats. Further, soils surrounding the treatment zone which are not smouldered will be heated, although not smouldered, by virtue of their proximity to STAR, impacting microbial communities within them. Therefore, the objectives of this work are to quantify the …

Multiscale Wind Modelling For Sustainability And Resilience, Djordje Romanic

Electronic Thesis and Dissertation Repository

The research presented herein is a mix of meteorological and wind engineering disciplines. In many cases, there is a gap between these two fields and this thesis is an attempt to bridge that gap through multiscale wind modelling approaches. Data and methods used in this study cover a multitude of spatial and temporal scales. Applications are in the fields of sustainability and resilience. This relationship between multiscale wind modelling and sustainability and resilience is investigated examining several case studies of three different developments: urban, rural and coastal.

An urban wind modelling methodology is proposed and applied for a specific development …

A Systems Approach To Modelling The Effects Of Climate Change On Agroforestry: A Case Study In Western Tanzania, Elaine M. Samuel

Electronic Thesis and Dissertation Repository

Climate change is anticipated to have significant effects on agricultural production in sub-Saharan Africa as the magnitude of weather events increase in severity. Smallholder farmers in western Tanzania are potentially vulnerable to climate change impact as crops rely on precipitation as the only source of water. It is prudent to evaluate different modes of agricultural adaptations, such as agroforestry, that these farmers can easily adopt to improve their resiliency to the effects of climate change. System dynamics modelling is a cost-effective tool to simulate the long-term behaviour of agroforestry systems under future climate conditions. Water, Nutrient, and Light Capture in …

Application Of Treated Oil Sands Drill Cuttings Waste In Micropiles Construction, Moustafa Ahmed Raafat Mohamed Aboutabikh

Electronic Thesis and Dissertation Repository

A micropile is constructed by drilling a hole, placing a steel reinforcing element, grouting it using neat cement. However, cement production consumes energy and generates carbon dioxide. Implementing waste materials in construction applications represents a sustainable solution for many waste management problems. On the other hand, oil sands drill cuttings waste represents one of the most difficult challenges for the oil sands mining sector. Reducing the amount oil sands drill cutting waste sent to landfill offers one of the best solutions for waste management. This thesis presents an innovative solution for application of treated oil sands waste (TOSW) in grout …

Tropical Cyclone Wind Hazard Assessment For Southeast Part Of Coastal Region Of China, Sihan Li

Electronic Thesis and Dissertation Repository

Tropical cyclone (TC) or typhoon wind hazard and risk are significant for China. The return period value of the maximum typhoon wind speed is used to characterize the typhoon wind hazard and assign wind load in building design code. Since the historical surface observations of typhoon wind speed are often scarce and of short period, the typhoon wind hazard assessment is often carried out using the wind field model and TC track model. For a few major cities in the coastal region of mainland China, simple or approximated wind field models and a circular subregion method (CSM) have been used …

Multi-Method Modeling Framework For Support Of Integrated Water Resources Management, Vladimir V. Nikolic

Electronic Thesis and Dissertation Repository

The existing definition of integrated water resources management (IWRM) promotes a holistic approach to water resources management practice. The IWRM deals with planning, design and operation of complex systems in order to control the quantity, quality, temporal and spatial distribution of water with the main objective of meeting human and ecological needs and providing protection from water disasters. One of the main challenges of IWRM is development of tools for operational implementation of the concept and dynamic coupling of physical and socio-economic components of water resources systems. This research examines the role of simulation in IWRM practices, analyses the advantages …

Influence Of Water Chemistry Parameters On The Dissolution Rate Of The Lead (Ii) Carbonate Hydrocerussite, Caitlin Se Kushnir

Electronic Thesis and Dissertation Repository

This work has focused on the kinetic dissolution of the lead (II) carbonate hydrocerussite (Pb₃(CO₃)₂(OH)₂) under four pH conditions (7.5, 8, 9, 10), three dissolved inorganic concentrations (DIC; 10, 20, 50 mg C/L), and three initial hydrocerussite concentrations (10, 20, 50 mg/L) in batch experiments. Experiments were performed in at least duplicate to determine total dissolved lead dissolution curves at short time scales (hr.). All equilibrium dissolved lead concentrations were achieved in 40 minutes or less, and matched trends from previous studies; pH 7.5 and pH 10 corresponding to the highest and …

Characterization Of The Green Roof Growth Media, Ginevra Alessandra Perelli

Electronic Thesis and Dissertation Repository

Green roofs are becoming a popular solution to manage the stormwater, to reduce the energy consumption in highly urbanized environment and provide many additional benefits. One of the key components that characterize the green roof system is the growth medium; the medium supports the plants, providing water and nutrient storage, and contributes to the roof insulation.

The object of this thesis is to investigate the hydraulic and the thermal properties of the green roof growth medium and to study the relationship among these properties through extensive laboratory analyses. In addition, the laboratory results are compared with direct measurements in the …

Full-Scale Tests Of A Wood-Frame Structure Under Extreme Wind Loads, Derek A. Stedman

Electronic Thesis and Dissertation Repository

Tornadoes can produce some of the strongest winds on earth; these highly localized storms can cause massive damage. Assessments of tornado wind speeds are done using post-event observations of damage via the Enhanced Fujita Scale.

A very commonly observed failure occurs at the roof-to-wall connection where the roof breaks up or flies away, typically leaving the walls in place. However, once the roof is gone the walls are more vulnerable to the wind. If a wall subsequently fails, it increases the risk of injury or death for occupants. Significant research has been done for failures of roof-to-wall connections and roof …

Experimental Modeling Of Wind Farm Topography And Canopy, Dan S. Parvu

Electronic Thesis and Dissertation Repository

As an important renewable energy source for electricity generation, wind energy must rely on efficient and accurate wind resource assessment for the siting and the design of wind farms. Traditionally relying on numerical modeling, current wind farms built in Canada, notably, experience an under-performance in terms of power generation. This work studies an alternative approach to wind farm modeling through experimental wind tunnel testing.

The objective of the work is to develop methodologies on how topographic and forest canopy models should be built as scale models of full scale wind farms. The models developed are validated by comparing the data …

Hydrogeological And Thermal Sustainability Of Geothermal Borehole Heat Exchangers, S. Emad Dehkordi

Electronic Thesis and Dissertation Repository

Assessment of the current approach taken by guidelines and design methods of vertical closed loop heat exchangers shows that often groundwater flow is either disregarded or is not methodically incorporated. The state of scientific research in this arena reveals that overlooking the groundwater flow in the design procedure may not always be a correct assumption. The significance of advective heat transport compared to conduction is defined by the groundwater flux or Darcy velocity which heavily depends on the hydraulic conductivity of the ground, followed by the hydraulic gradient which has a relatively limited range. A sensitivity analysis on ground and …

Climate Change Impact On Flood Hazard In The Grand River Basin, Ontario, Canada, Abhishek Gaur

Electronic Thesis and Dissertation Repository

Rapidly changing climatic conditions across the globe are believed to have an impact on key climate variables and the hydrologic cycle. Changes in magnitude and frequency of peak flow patterns have been noted in rivers worldwide. The associated risk is projected to increase many folds during the 21^st century. Therefore, it is necessary to quantify these impacts for effective water resource planning and management in future. Methodology chosen to do so should be able to capture variations in climate variables at fine temporal, spatial and distributional scales. Also, it should be able to cover uncertainties associated with future climatic, …

Load-Sharing Of Toe-Nailed, Roof-To-Wall Connections Under Extreme Wind Loads In Wood-Frame Houses, Mohammad Khan

Electronic Thesis and Dissertation Repository

A typical wood frame house roof consists of trusses which are nailed to the top-plates of the wall assembly. These are known as roof-to-wall connections (RTWCs). A load-sharing mechanism is developed between adjacent RTWCs via roof elements such as roof-sheathing, fascia beams, etc., during high wind loads. An experimental setup was developed to observe the load-sharing behavior between seven connections. To mimic the roof bending stiffness in the direction perpendicular to the trusses, two steel beams with representative bending stiffness were connected across the RTWCs in a simple way. Identical ramp and identical fluctuating wind loads were applied to all …

Uncertainty Estimation Of Extreme Precipitations Under Climate Change: A Non-Parametric Approach, Tarana A. Solaiman

Electronic Thesis and Dissertation Repository

Assessment of climate change impacts on hydrology at watershed scale incorporates (a) downscaling of global scale climatic variables into local scale hydrologic variables and (b) assessment of future hydrologic extremes. Atmosphere-Ocean Global Climate Models (AOGCM) are designed to simulate time series of future climate responses accounting for human induced green house gas emissions. The present study addresses the following limitations of climate change impact research: (i) limited availability of observed historical information; (ii) limited research on the detection of changes in hydrologic extremes; and (iii) coarse spatio-temporal resolution of AOGCMs for use at regional or local scale. Downscaled output from …

Early-Age Shrinkage Of Ultra High-Performance Concrete: Mitigation And Compensating Mechanisms, Ahmed Mohammed Soliman

Electronic Thesis and Dissertation Repository

The very high mechanical strength and enhanced durability of ultra high-performance concrete (UHPC) make it a strong contender for several concrete applications. However, UHPC has a very low water-to-cement ratio, which increases its tendency to undergo early-age shrinkage cracking with a risk of decreasing its long-term durability. To reduce the magnitude of early-age shrinkage and cracking potential, several mitigation strategies have been proposed including the use of shrinkage reducing admixtures, internal curing methods (e.g. superabsorbent polymers), expansive cements and extended moist curing durations. To appropriately utilize these strategies, it is important to have a complete understanding of the driving forces …