Master of Sciences (Engineering), Case Western Reserve University, 2014, EMC - Mechanical Engineering

To better understand the behavior of wind turbines placed in an urban environment, a study was performed to characterize the wind availability and performance of a 100-kilowatt Northern Power Systems wind turbine installed at Case Western Reserve University. It was found that the annual average wind speed was 4.0m/s, generating net energy of 67MWh at a rate of 8.0kW. It was also found that the winds rarely reach the required 15m/s for the turbine to output at its rated capacity. The winds that do reach 15m/s or faster exist only in short gusts, prevalently during the Winter 2011 and Spring 2012 months. Additionally, in studying the turbine performance, it was found that the turbine has a maximum efficiency of 65-70% relative to the Betz Limit, at a wind speed of approximately 6.75m/s.

Committee: Iwan Alexander (Advisor); Jaikrishnan Kadambi (Committee Chair); Paul Barnhart (Committee Member) Subjects: Aerospace Engineering; Energy; Engineering; Mechanical Engineering

Master of Science in Renewable and Clean Energy Engineering (MSRCE), Wright State University, 2017, Renewable and Clean Energy

People understand and have seen that renewable energy has many advantages over conventional energy sources. Because of these advantages, more and more emphasis has been given to generating electrical energy with renewable sources. Among the many renewable and conventional ways currently available for a society to generate electrical power, wind turbines are one of the cheapest ways of doing this. The main objective of this thesis work is to develop a computer program that assesses the wind resource at a given location, designs a wind turbine rotor for optimum power capture for one wind speed, and analyzes the performance of this designed rotor over a range of wind speeds. A key output of this computer program is the energy that a wind turbine can produce over a one year period, at a given location. Many other results are produced by this newly developed computer program as well. This computer program allows for three different air foil types to be used on a single blade. Using more than one airfoil type along a single blade is necessary for good performance of larger diameter wind turbines. While the computer model developed for this thesis work is applicable to any location, any elevation, and any time period; results are produced for only one location and one hub height. The location studied is Eaton, Ohio and the hub height is 70 meters above the ground. Plots and single numbers that describe the Eaton wind resource are presented. A 20-meter radius wind turbine rotor is designed using three NREL S-series airfoils along the length of each blade of a three-bladed wind turbine rotor. For the root section of the blade a S818 airfoil is used, for the primary section of the blade a S816 airfoil is used, and for the tip section of the blade a S817 airfoil is used. A couple of design parameters are surveyed along with one operational parameter.

Committee: James A. Menart Ph.D. (Advisor); Hong Huang Ph.D. (Committee Member); Zifeng Yang Ph.D. (Committee Member) Subjects: Alternative Energy; Mechanical Engineering; Mechanics

Master of Science in Engineering, Youngstown State University, 2010, Department of Civil/Environmental and Chemical Engineering

The siting of modern wind turbines to generate electricity requires accurate wind flow data over at least an annual weather cycle for optimum selection of both the wind turbine and its installed height, as well as for predicting the expected annual energy production at the site. Since wind energy is a relatively new industry in North America, detailed annualized data are often not available, especially in rural areas, except for a single prediction of the average annual wind speed that is modeled by interpolating weather data from sensors that may be located several miles from the intended wind turbine site. This has led to several user disappointments when the actual energy obtained from a wind turbine was less than predicted. In response, the present study focused on the development of a more realistic predictive model of power generation based on actual wind patterns at the site. Data on wind flow and energy output were obtained from an installation of three industrial-sized wind turbines at a local K-12 school. Minute-by-minute wind data were sorted and aggregated to provide the model input. The empirical model developed predicted energy output within 4.1% of that observed over a period of 78 days; that is, an estimate of 13,875 kWh versus 14,470 kWh actually produced. A simpler model applicable to lower wind speeds (up to a “Moderate Breeze” of 7.5 m/s) was also developed that yielded a good energy output estimate of 11.5 kWh versus the full model's estimate of 11.7 kWh for an actual day's wind conditions.

Committee: Scott Martin PhD (Advisor); Javed Alam PhD (Committee Member); Salvatore Pansino PhD (Committee Member) Subjects: Area Planning and Development; Civil Engineering; Energy; Environmental Engineering

Master of Science in Mechanical Engineering, Cleveland State University, 2013, Fenn College of Engineering

This project involves study of 2-Blade and 3-Blade Savonius vertical wind turbines positioned at different orientations. For a 2-Blade turbine the orientations considered were 0 degree, 45 degree, 90 degree and 135 degree in reference to the direction of the prevailing wind and for the 3-Blade turbine the orientations taken into account were 0 degree, 30 degree, 60 degree and 90 degree in reference to the direction of the prevailing wind. The basic aim of this thesis was to study how the two designs are different from each other and which design produces more power when applied with constant wind velocity of 10mps. Computational Fluid Dynamics (CFD) analyses were conducted for every case to find out the torque and power generated by the turbines for each orientation. To ensure the accuracy of the results, CFD techniques were applied using Gambit 2.2.30 and Fluent 6.2.16. All cases were run using “transition-SST” flow model and the faces were meshed using `Quadrilateral Pave' meshing scheme. The turbine was also tested for varying wind velocities of 5mps, 20mps, and 30mps for a constant orientation of turbine. The results were later compared and graphs were created for easy comparison of power and torque generated by turbines at different velocities. Maximum change in pressure occurs when 2-Blade turbine in perpendicular to direction of wind flow direction i.e. at 90 degree and when 3-Blade turbine is at 60 degree orientation. The 2-Blade Turbine generates higher value of torque (215.28 N) as compared to 3-Blade turbine, generating torque of value 110.92 N for any given constant wind velocity; 30mps in this case. This information can help the designer of the system to select the proper wind turbine considering the efficiency and stability along with other factors.

Committee: Majid Rashidi PhD (Committee Chair); Rama Gorla PhD (Committee Member); Asuquo Ebiana PhD (Committee Member) Subjects: Mechanical Engineering

Master of Sciences (Engineering), Case Western Reserve University, 2010, EMC - Fluid and Thermal Engineering

In this study, a code ‘Wind Farm Optimization using a Genetic Algorithm' (referred as WFOG) is developed in MATLAB for optimizing the placement of wind turbines in large wind farms to minimize the cost per unit power produced from the wind farm. A genetic algorithm is employed for the optimization. WFOG is validated using the results from previous studies. The grid spacing (distance between two nodes where a wind turbine can be placed) is reduced to 1/40 wind turbine rotor diameter as compared to 5 rotor diameter in previous studies. Results are obtained for three different wind regimes: Constant wind speed and fixed wind direction, constant wind speed and variable wind direction, and variable wind speed and variable wind direction. Cost per unit power is reduced by 11.7 % for Case 1, 11.8 % for Case 2, and 15.9 % for Case 3 for results obtained using WFOG. The advantages/benefits of a refined grid spacing of 1/40 rotor diameter (1 m) are evident and are discussed.

Committee: J. Iwan D. Alexander PhD (Committee Chair); Alexis R. Abramson PhD (Committee Member); Jaikrishnan R. Kadambi PhD (Committee Member); Joseph M. Prahl PhD (Committee Member) Subjects: Energy; Mechanical Engineering

Master of Science in Mechanical Engineering, University of Toledo, 2012, Mechanical Engineering

This thesis examines the effects of surface ice sheets on an offshore wind turbine. First, the main ice load cases are presented, and methods used to calculate the loads from each of these cases are explained. These load cases consist of loads from moving ice sheets, loads from non-moving ice sheets, and loads from agglomerated masses of ice, called ice ridges. Next, the data required to conduct the load calculations are presented from sources applicable to an offshore site in Lake Erie, which is the location of interest in this work. The load calculation methods were implemented into a wind turbine simulation software package, and simulations were run subjecting an offshore wind turbine to extreme ice loads combined with a large representative wind load. Results from these simulations are presented, which show the relative magnitude of the effects of the ice loads compared to the magnitude of the effects of the wind load. It was found that the effects on the foundation due to extreme ice loads can be much larger than the effects caused by a large representative wind load. Also presented in this work is an examination of how the ice loads would influence the design of an offshore wind turbine foundation (i.e. how much bigger should the foundation be to support the ice loads). The simulation results presented in this study indicate that the surface ice sheet loads can be much larger than the wind loads and could be the driving parameter of the design of offshore wind turbine foundations in areas where ice can occur.

Committee: Abdollah Afjeh Dr. (Committee Co-Chair); Sorin Cioc Dr. (Committee Co-Chair); Efstratios Nikolaidis Dr. (Committee Member) Subjects: Mechanical Engineering

Master of Science in Engineering, Youngstown State University, 2024, Department of Mechanical, Industrial and Manufacturing Engineering

This research investigates the optimization of vertical axis wind turbine (VAWT) systems to harvest energy from vehicle-induced highway winds. The primary objective is to enhance the efficiency of small-scale VAWTs mounted on the side of highways, enabling the generation of electrical energy or clean hydrogen production. Computational fluid dynamics (CFD) modeling was employed to systematically optimize the turbine design and to develop wind guides that further increase the efficiency. The study found that an elliptical VAWT design demonstrated a 4.4% higher power coefficient compared to a Savonius VAWT. Introducing a single flat or curved guide between the turbine and the road increased the power output by 145.33%. Further refinements, including the use of three guides with optimized angles and radii, culminated in a remarkable 393.16% improvement over the initial non-guided-guided configuration. In the non-guided-guided scenario, simulating the VAWT's exposure to the wake flow induced by a bus traveling at 32 m/s, the CFD analysis predicted an energy output of 30.41 Nm. However, when the three guide vane configuration was employed, the energy output exhibited a substantial increase, reaching 100.41 Nm under the same bus speed conditions. The comparative analysis between the Non-guided-guided and three-guide vane setups for the bus wake simulations revealed a remarkable 230% enhancement in energy capture when the guide vanes were incorporated. This significant performance improvement highlights the favorable impact of the optimized guide vane arrangement on the aerodynamic behavior of the VAWT, facilitating more effective extraction of energy from the wake flows generated by larger vehicles such as buses. The results showcase the significant potential of vehicle-induced highway winds as a viable source of renewable energy. The optimized VAWT system, incorporating multiple flow guides, demonstrates the ability to effectively harness this untapped resourc (open full item for complete abstract)

Committee: Stefan Moldovan PhD (Advisor); Hazel Marie PhD (Committee Member); Eric Haake MSE (Committee Member) Subjects: Alternative Energy; Energy; Engineering; Mechanical Engineering; Sustainability

Doctor of Philosophy (Ph.D.), University of Dayton, 2018, Aerospace Engineering

So-called wind-lens turbines offer the potential for improved energy efficiency and better suitability for urban and suburban environments compared to unshrouded or bare wind turbines. Wind-lenses, which are typically comprised of a diffuser shroud equipped with a flange, can enhance the wind velocity at the rotor plane due to the generation of a lower back pressure. This work comprises of two main studies which aim to develop fast and accurate simulation tools for the performance prediction and design of shrouded horizontal axis wind turbines. In the first study, a low-order theoretical model of ducted turbines is developed to establish a better understanding of the basic aerodynamics of shrouded wind turbines. Then a cost-effective CFD tool coupled with a multi-objective genetic algorithm is developed and employed to improve the performance of shrouded wind turbines. A low-order semi empirical model, which offers performance prediction for the power and thrust coefficients, is developed and applied to shrouded turbines. This 1D model is based on assumptions and approximations to calculate optimal power coefficients and power extraction, as well as augmentation ratios. It is revealed that the power enhancement is proportional to the mass stream rise produced by the nozzle diffuser-augmented wind turbine (NDAWT). Such mass flow rise can only be accomplished through two essential principles: an increase in the area ratios and/or by reducing the negative back pressure at the exit. The thrust coefficient for optimal power production of a conventional bare wind turbine is known to be 8/9, whereas the theoretical analysis of the NDAWT predicts an ideal thrust coefficient either lower or higher than 8/9 depending on the back-pressure coefficient at which the shrouded turbine operates. Computed performance expectations demonstrate a good agreement with numerical and experimental results, and it is demonstrated that much larger power coefficients than for traditional win (open full item for complete abstract)

Committee: Markus Rumpfkeil Ph.D. (Advisor); Kevin Hallinan Ph.D. (Committee Member); Andrew Chiasson Ph.D. (Committee Member); Youssef Raffoul Ph.D. (Committee Member) Subjects: Aerospace Engineering; Mechanical Engineering

Master of Sciences, Case Western Reserve University, 2018, Physics

Boundary Labs, LLC is an early-stage company composed of three students at Case Western Reserve University which aimed to evaluate the feasibility of commercialization of a novel dielectric barrier discharge (DBD) plasma actuator as an active flow control (AFC) method in wind turbines. The hypothesized benefits of DBD plasma actuators for AFC include improved energy capture from wind, low cost, and ease of implementation. This thesis is a two-part case study. The first part emulates a Small Business Innovation Research (SBIR) Phase I Proposal for the technology and includes discussions arguing that a strong commercial potential for the proposed technology exists in the United States and that technical development is feasible. The second part includes miscellaneous sections outside the scope of an SBIR proposal, leading to a discussion of the Boundary Labs team decision to discontinue development of this technology.

Committee: Edward Caner (Committee Chair); Robert Brown (Committee Member); Michael Martens (Committee Member) Subjects: Alternative Energy; Energy; Entrepreneurship; Physics

Master of Engineering, Case Western Reserve University, 2016, EECS - Electrical Engineering

Finnish Engineer Sigurd Savonius introduced a vertical drag rotor in 1922 and named it Savonius turbine. It consists of two semi cylindrical blades in an “S” shape from the top view. Savonius turbines provide some advantages such as a simple and low-cost structure, self-starting capabilities and the ability to use wind speed from any direction. Savonius machines are widely used in many ways, including pumping and sailing. However, it has a poor power coefficient, typically in the range of 10% to 15%. In order to find new solutions to improve the aerodynamic efficiency, this project designs, manufactures and tests experimentally six Savonius prototypes. The prototypes combine different geometric characteristics. Coefficient of torque and coefficient of power for each prototype are measured. The experimental validation is conducted at the fully instrumented wind tunnel. The results give guidelines to improve the efficiency and reduce the cost of the Savonius wind turbines. Maximum power point tracking for Savonius turbine is also investigated.

Committee: Mario García-Sanz (Advisor); Marija Prica (Committee Member); Vira Chankong (Committee Member) Subjects: Electrical Engineering

Master of Sciences, Case Western Reserve University, 2014, EECS - System and Control Engineering

WindLCOE is a novel new tool developed through this project for wind turbine designers to promote return on investment by calculating the Levelized Cost of Energy (LCOE) for wind energy systems. The purpose of this MATLAB tool is to allow designers to calculate and find the optimal parameters for wind turbine design under multiple scenarios. These scenarios can vary in both the design of the wind energy system and the wind distribution it would be operating within. The WindLCOE tool is valuable to the wind energy field by providing an adaptable way to calculate the Levelized Cost of Energy that can be easily updated to reflect changes and advancements in wind energy design.

Committee: Mario Garcia-Sanz (Advisor); Francis Merat (Committee Member); Christos Papachristou (Committee Member) Subjects: Systems Design

Master of Science, The Ohio State University, 2012, Electrical and Computer Engineering

Wind turbine has been popular in the area of renewable energy source. Wind turbine has shown the biggest growth in the past 10 years compared to other renewable sources. Permanent Magnet Synchronous Generator (PMSG) used as wind turbine generator. PMSG is suitable for the application due to its high efficiency, high torque-to-size ratio, and low maintenance requirement. The intermittent characteristic of wind requires a wind turbine to have good control system. This thesis discusses the Field Oriented Control (FOC) and Hysteresis Current Control (HCC) technique used to control the generator-side and grid-side respectively. In order to perform these controls, good understanding of the PMSG and electrical grid are required. In addition, reference frame theory and Space Vector Modulation are explained as supplement theories used for the Field Oriented Control. A MATLAB/Simulink simulation has been developed to simulate the control algorithms.

Committee: Ali Keyhani PhD (Advisor); Mahesh Illindala PhD (Committee Member) Subjects: Alternative Energy; Energy; Engineering

Master of Arts, The Ohio State University, 2010, East Asian Languages and Literatures

This thesis focuses on China's wind energy development, focusing on data pertaining to effects of wind energy development on economic, environmental, and social issues. It also reviews the Chinese government's Wind Energy development policy, laws that encourage the development of wind energy, as well as wind energy development problems and future development plans. I will also address current trends in China's wind energy development, as well as present the results of my field research.

Committee: Galal Walker Dr. (Advisor); Jianqi Wang (Advisor) Subjects: Energy

Master of Science, The Ohio State University, 2009, Electrical and Computer Engineering

The global electrical power demand is steadily increasing. The absolute dependence of conventional energy resources such as oil, coal or natural gas to meet this demand is problematic for many reasons: its environmental impacts such as pollution and global warming caused by greenhouse emissions, the rising and unstable prices for fossil fuels and for some nations energy security is considered as indispensable part of the national security.Therefore, renewable energy technologies have been playing a key role in the worldwide electrical power production. The advancement of power electronics in terms of efficiency and functionality along with their declining cost all have increased the contribution of renewable energy systems in the electricity generation and solved significant problems in integrating those technologies with existing power systems . Among renewable wind energy is the fastest growing, however world has abundant amount of usable wind energy which has not been utilized. This thesis firstly discusses the contributions of some conventional energy sources in electricity generation , then it covers essential topics about wind turbine systems such as the power content of wind , the components and operation of wind turbine system , power and speed control methods implemented in modern turbine systems and the electrical systems for wind turbines with focus on generators and power converters used. Finally, it deals with the core topic which is the bi-directional three-phase power converter using pulse width modulation (PWM). PWM techniques in power converters are gaining importance especially for harmonics control. The thesis presents the mathematical modeling of the converter and a computer simulation for its operation using Matlab/Simulink , then the analysis of the input/output characteristics is presented.

Committee: Ali Keyhani Prof. (Advisor); Donald Kasten Prof. (Committee Member) Subjects: Electrical Engineering

BA, Oberlin College, 2008, Economics

As concern over global climate change and fears of rising energy costs permeate our collective and individual decision making, more and more private institutions are seeking out innovative and feasible solutions to meet these issues. Many colleges and universities throughout the United States have been among the first private and public institutions to dedicate themselves to positions of climate neutrality and have begun to incorporate the ethics of conservation and commitment to environmental sustainability into their primary objectives. To date nearly five hundred institutions of higher education have signed the American College and Universities Climate Change Commitment, pledging to take immediate and prolonged action to reduce their foot print of carbon dioxide and other greenhouse gas emissions. Undoubtedly many of these schools will be able to implement extensive and inexpensive improvements in the efficiency of current facilities and practices in order to meet their objectives. However for those that have committed to complete climate neutrality, such as Oberlin College, additional measures extending beyond the traditional endeavors of an educational institution may also become necessary. One such option that has received attention from the Oberlin community is the construction of a utility scale wind turbine. Although there are many other alternatives that the College may investigate, the choice to be considered here is between investing in a wind turbine or purchasing carbon offsets commercially. Naturally the college faces tradeoffs as it allocates its budget between turbines, offsets, and its myriad other operational activities, so a cost benefit analysis is particularly useful in comparing the advantages and disadvantages of investment in various turbine models. This paper addresses several primary objectives. First, the analysis conducted here will update previous research on the topic of the viability of wind power in Oberlin by incorporating spot mark (open full item for complete abstract)

Committee: Jordan Suter (Advisor); Barbara Craig (Other); Hirschel Kasper (Other); David Cleeton (Other); Shreemoy Mishra (Other); John Scofield (Other) Subjects: Alternative Energy; Economic Theory; Economics

Master of Science (M.S.), University of Dayton, 2010, Aerospace Engineering

An investigation into wake and solid blockage effects of Vertical-Axis Wind Turbines (VAWTs) in closed test-section wind tunnel testing is described. Static wall pressures have been used to derive velocity increments along a wind tunnel test-section which in-turn are applied to provide evidence of wake interference characteristics of rotating bodies interacting within this spatially restricted domain. Vertical-axis wind turbines present a unique aerodynamic obstruction in wind tunnel testing whose blockage effects have not been extensively investigated.The flow-field surrounding these wind turbines is asymmetric, periodic, unsteady, separated and highly turbulent. Static pressure measurements are taken along a test-section sidewall to provide a pressure signature of the test models under varying rotor tip-speed ratios (freestream conditions and model RPM's). To provide some guidance on the scaling of the combined effects of wake and solid blockage, wake characteristics and VAWT performance produced by the same vertical-axis wind turbine concept have been tested at different physical scales in two different wind tunnels. This investigation provides evidence of the effects of large wall interactions and wake propagation caused by these models at well below generally accepted standard blockage figures.

Committee: Aaron Altman PhD (Committee Chair); Jewel Barlow PhD (Committee Member); Eric Lang PhD (Committee Member) Subjects: Aerospace Materials; Engineering; Experiments; Fluid Dynamics; Mechanical Engineering

Master of Sciences, Case Western Reserve University, 2011, EMC - Mechanical Engineering

Two-dimensional shape of a wind turbine blade was optimized by means of Particle Swarm Optimization. By following blade element theory, lift coefficient Cl and drag coefficient Cd were used as objective functions. In order to compute the objective functions, flow field around airfoils were calculated by Re-Normalization Group (RNG) k-ε model. Shapes of airfoils were defined by modified PARSEC method with 10 parameters.Two optimization cases were conducted with maximum thickness limited to 10% and 20% of the chord length respectively. In both cases, Reynolds number was set at 2.0×106, which is the design condition of S809 airfoil. S809 airfoil is a well known airfoil used in wind turbines and many experimental data are available. The angle of attack for the optimization was set at 5.13 deg., the mount angle of S809. Non-dominated solutions obtained by this research were compared with the performance of S809 at several angles of attack. The results of optimization showed that 1) there is a strong influence of maximum thickness of airfoil to its performance, 2) non-dominated solutions constitute a gradual relationship which implies that there are many airfoil shapes that could be considered as an optimum. The resulting shape along this Pareto front showed higher performance than the existing blade section (i.e. NREL S809) in certain conditions.

Committee: James S. T'ien PhD (Committee Chair); Meng-Sing Liou PhD (Committee Member); J. Iwan D. Alexander PhD (Committee Member) Subjects: Aerospace Materials; Ecology; Energy; Engineering; Fluid Dynamics; Mechanical Engineering

Master of Science, Miami University, 2024, Mechanical and Manufacturing Engineering

A new method is proposed to mitigate ice accretions on wind turbine blades via the creation of a microstructural gradient surface geometry that facilitates spontaneous water droplet motion along the surface. The wettability gradients are formed by laser etching 35𝜇m wide, 35𝜇m deep channels into aluminum to form a surface with a gradually increasing solid area fraction. Different design permutations are then proposed and systematically evaluated on the merits of their performance. An analytical model is also derived based on a balance of hysteresis and drag forces to predict the critical airspeed necessary for droplet movement as a function of the droplet size and surface contact angle. Experimentation has shown good agreement with the model for both the baseline and fixed-pitch channel surfaces and has also demonstrated that, in certain cases, up to 70% lower critical airspeeds are needed to initiate droplet motion on these microstructured surfaces. Finally, the effects of frozen droplets on aerodynamic performance were studied via 3D-printed airfoil prototypes. This work demonstrated that at airspeeds under <15m/s and angles of attack between 0 – 20 degrees, frozen droplets on the top surface of the airfoil can be used to strengthen the lift-to-drag ratio by up to 184

Committee: Andrew Sommers (Advisor); Medhi Zanjani (Committee Member); Edgar Caraballo (Committee Member) Subjects: Alternative Energy; Energy; Engineering; Fluid Dynamics; Mechanical Engineering

Doctor of Philosophy, Case Western Reserve University, 2022, EECS - System and Control Engineering

In this thesis, a control methodology that merges the adaptive extremum seeking control (ESC) with the robust quantitative feedback theory (QFT) into one compact control scheme is proposed. It utilizes the properties inherent in both methods to develop a novel control law that guarantees the convergence of a systems performance function driven by a plant model to meet multiple robust control performance objectives simultaneously. The system structure is set up to have the output of a linear time-invariant (LTI) model with structured uncertainties as the operating variable for a nonlinear objective function with possibly time-varying parameters. A new bound called the extremum seeking bound (ESB) is introduced to the QFT design process. By utilizing the information derived from tuning the ESC scheme for the systems static function, an ESB can be constructed that accounts for the speed of convergence of the ESC scheme and then combined with the other classical QFT bounds to design a controller that is both adaptive and robust for the system structure presented. The control architecture for this design is presented and used to develop the conceptual basis and detailed mathematical justification for the control law. The robust extremum seeking control (RESC) design is validated on two engineering problems using MATLAB and Simulink. One is a nonlinear system with time-varying parameters driven by a dynamical model with uncertain parameters that is described at a high level of abstraction to demonstrate the general applicability of the design method. The second, a specific engineering problem, is the design of a generator torque controller of a 10 kilowatts (KW) wind turbine for maximum power point tracking (MPPT) in region 2 operation.

Committee: Mario Garcia-Sanz (Advisor); Christian Zorman (Committee Member); Evren Gurkan-Cavusoglu (Committee Member); Vira Changkong (Committee Member) Subjects: Applied Mathematics; Electrical Engineering; Engineering; Mechanical Engineering; Systems Design

Master of Science in Mechanical Engineering, Cleveland State University, 2021, Washkewicz College of Engineering

This study presents a mathematical modeling of behavior of a wind deflecting structure having trap doors supported by gravity hinges. The function of the trap doors is to be fully closed at low wind speeds (under 6.1 m/s), thereby increasing the wind speed, and directing the air flow to a pair of roof top wind turbines (1.3 kW nameplate rating). With wind speeds higher than 6.2 m/s the trap doors will start to open, letting the air move though the structure rather than directing the air flow to the turbines. The opening and closing of the trap doors take place with the help of gravity hinges. Under high-speed wind conditions, the follower of the gravity hinge climbs up the cam surface. As long as the wind speed stays high, the trap door stays open. When the wind speed falls below a prescribed value, the force of gravity acting on the trap doors is a restoring force to bring the trap door into its closed configuration. This study includes the drag force calculations on the trap doors, the torque created by this drag force in an analysis to examine the opening and closing behavior of the trap door under various wind speed conditions. Under the closed trap door position, wind velocity analysis was performed in order to demonstrate the intended function of the wind deflecting structure for amplifying the natural wind speed. A detailed static analysis of the gravity hinge was performed to examine the condition of opening of the trap doors under high wind conditions. A series of parametric studies were performed to demonstrate the behavior of trap doors under low and high wind speed conditions. A gravity hinge of a 5-degree incline was considered in this study and the analysis shows the trap doors stay closed for wind speeds of 6.2 m/s and below. Furthermore, the analysis shows that the trap door is fully open for wind speeds above 18 m/s. A range of friction coefficient between 0.01 and 0.1 was considered acting on the components of the gravity hinge.

Committee: Majid Rashidi (Advisor); Maryam Younessi Sinaki (Committee Member); Michael Gallagher (Committee Member) Subjects: Mechanical Engineering