Master Theses & Projects (FEAS)

Permanent URI for this collectionhttps://hdl.handle.net/10155/687

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Characterization of flow control using programmable multi-directional plasma actuators
(2023-09-01) Gustin, Samuel W.; Agelin-Chaab, Martin
This research explores the use of a novel plasma actuator geometry and electrical configuration to generate directionally programmable flow fields near the surface of arrays of such plasma actuators. Plasma actuators are unique ionothrusters which are reliant on geometry to define flow directionality. This thesis defines and makes use of a new class of plasma actuator which can generate directionally differentiated flows within a single geometry via use of high voltage switches and specialized geometries. The multidirectional plasma actuators are trialed individually and in arrays and the space defined by the directionality of flows which can be generated is defined. It is found that these devices are capable of generating flows sufficient to create flow modifications which are beneficial for the efficiency and control of lifting bodies and airframes. The research demonstrates that the described programmable, multi-directional, plasma actuators may be used to create an assortment of desired flows and to aid in the control of airframes.
Comparative study of various hydrogen production methods for vehicles.
(2014-12-01) Suleman, Fahad; Dincer, Ibrahim; Agelin-Chaab, Martin
Hydrogen as an energy carrier is a promising candidate to store green energy and it has a potential to solve various critical energy challenges. Although, hydrogen is a clean energy carrier, the possible negative impacts during its production cannot be disregarded. Therefore life cycle analyses for various scenarios have been investigated in this study. In this thesis, a comparative environmental assessment is presented for different hydrogen production methods. The methods are categorized on the basis of various energy sources such as renewables and fossil fuel. For the fossil fuel based hydrogen production, steam methane reforming (SMR) of natural gas is studied. Renewable based hydrogen production includes electrolysis using sodium chlorine cycle. Electrolytic hydrogen production is also compared using different cells such as membrane cell, diaphragm cell and mercury cell. Wind and solar based electricity is also used in electrolytic hydrogen production. Furthermore, vehicle cycle is studied on the basis of available literature to compare the hydrogen vehicle with gasoline vehicle. The investigation uses life cycle assessment (LCA), which is an analytical tool to identify and quantify environmentally critical phases during the life cycle of a system or a product and/or to evaluate and decrease the overall environmental impact of the system or product. The LCA results of the hydrogen production processes indicate that SMR of natural gas has the highest environmental impacts in terms of abiotic depletion, global warming potential, and in other impact categories. The abiotic depletion for SMR is found to be 0.131 kg Sb eq. which is the highest among all methods. The second highest abiotic depletion value comes under electrolysis using mercury cell which is 0.00786 kg Sb eq. However, thermodynamic results suggested that SMR is the efficient method of hydrogen production because the amount of hydrogen energy produced as output in the system is larger than any other method. The energy efficiency of the system in this method is about 76.8% and the exergy efficiency is about 72.4%. In terms of vehicle cycle comparison, it is found that the gasoline vehicle appears to be the largest contributor in energy consumption and GHGs emissions. The energy consumption of gasoline vehicle is three times higher than hydrogen vehicle. Moreover, GHGs emissions of the hydrogen vehicle are 8% of the gasoline vehicle.
Design and analysis of a sustainable energy system for a military base in the Canadian Arctic
(2023-08-01) Ironside, Mark J.; Agelin-Chaab, Martin
The purpose of this thesis was to propose and thermodynamically analyze a sustainable energy system for a military base in the Canadian Arctic for heating, electricity, farming, fresh water, hot water and waste management. This study is relevant because of the opening up of the Arctic passages and the consequent increase of military presence there. Therefore, an integrated wind powered energy generation system has been proposed and thermodynamically analyzed. The system was designed with a capacity of 51 MW and hydrogen storage of 229 tons. The results show promise with energy and exergetic efficiencies of 64% and 41%, respectively. Furthermore, the proposed system has lower lifecycle costs and emissions than that of its diesel counterparts, which are generally employed in northern Canada.
Design and analysis of an active underbody aerodynamic device for tractor trailers
(2018-04-01) Ibrahim, Mohamed; Agelin-Chaab, Martin
At highway speeds, up to 65 % of the total energy used by large trucks is for overcoming aerodynamic drag. The underbody region of a tractor-trailer is responsible for up to 30 % of the aerodynamic drag on tractor-trailers, which is the highest drag created by any region on the vehicle. In this study, a novel concept of an active underbody drag reduction device is developed and investigated. The device was evaluated and optimized using computational fluid dynamics (CFD) techniques. It successfully decreased the drag coefficient of the tractor-trailer model by 4.1 %. Additionally, the device eliminated the underbody recirculation region and reduced the negative adverse pressure in the wake. A novel mechanism is also developed to allow for the active deployment of the device to mitigate some operational issues such as roadway protrusions, parasitic drag at low speeds, snow and dirt accumulation.
Design of a residential air source heat pump for extremely cold climates
(2023-05-01) Besada, Wahid; Agelin-Chaab, Martin
Air source heat pumps are energy efficient systems suitable for space heating applications, however, their performance drastically degrades in low ambient temperatures. An innovative design is proposed in this thesis that can switch operating modes to allow efficient heating operation in an ambient temperature range of -50 °C to +20 °C. The proposed design is modeled and analyzed in detail, and the system performance is applied to weather data of two northern Canadian cities. The results show remarkable performance improvement, with around 30% annual energy savings compared to similar systems available in the market. The coefficient of performance is above 2.0 and 1.5 for temperatures as low as -30 °C and -50 °C, respectively. In addition, the heating capacity is almost steady despite decreasing lower ambient temperatures, thereby solving one of the biggest challenges of this technology and eliminating the need for auxiliary heating systems, as is the current practice.
Design optimization of aerodynamic drag at the rear of generic passenger cars using nurbs representation
(2013-05-01) Ghani, Osama Abdul; Barari, Ahmed; Agelin-Chaab, Martin
The rear geometry of a passenger car has the most significant influence on its aerodynamic characteristics. This thesis studied aerodynamic shape optimization of the rear geometry of passenger cars. The Non-uniform rational B-spline (NURBS) curve was used to represent the rear body of a generic passenger car model (the Ahmed Body) and the NURBS parameters were employed for geometry parameterization. These geometry parameters were systematically modified using design of experiments to obtain different geometries of the simplified car model. The computational fluid dynamics (CFD) simulations were performed on these geometries to obtain drag coefficients. Once the results of CFD simulations were available, a response surface model was constructed using linear regression technique. Finally, the design exploration was performed using the response surface model instead of actual CFD simulations. This technique resulted in a radical simplification of the design process as the behaviour of the aerodynamic drag was predicted using a simple polynomial. The proposed methodology was implemented to perform design exploration of a generic fast back model. The response surface model was able to predict the aerodynamic drag coefficients within an error of 5%. Aerodynamic shape optimization was also performed on a generic notch back model using the response surface technique and the optimized geometry parameters for minimum drag were obtained in only 18 iterations. On the basis of the results, it can be concluded that the proposed methodology is inexpensive, simple and robust. It can therefore provide the basic framework for the design and development of low drag passenger cars.
Design synthesis of NLMPC-based tracking controller for autonomous vehicles with active aerodynamic control
(2022-12-01) Mao, Chunyu; He, Yuping; Agelin-Chaab, Martin
The past three decades have witnessed extensive studies on tracking-control for autonomous vehicles (AVs). However, there is a lack of studies on effective design methods in this field. To tackle this problem, this thesis proposes a design synthesis method which is featured a design framework with two layers: at the upper layer, a particle swarm optimization algorithm is used to find optimal solutions with desired trajectory-tracking performance; at the lower layer, a comprehensively coupled dynamic analysis is conducted among the three subsystems, including a nonlinear vehicle model with active aerodynamic control for mechanical vehicle representation, a motion-planning module with given perception data, and a tracking controller based on non-linear model predictive control (NLMPC) for direction and lateral stability control. The design optimization demonstrates that the proposed method can effectively determine the desired design variables to achieve optimal trajectory-tracking performance. The insightful findings from this study will provide valuable guidelines for designing autonomous vehicles.
Development and analysis of a new direct steam generation-based parabolic trough collector power plant hybridized with a biomass boiler
(2016-10-01) Alhayek, Bashar; Agelin-Chaab, Martin; Reddy, Bale
Direct steam generation (DSG) is the process by which steam is directly produced in parabolic trough fields and supplied to a power block. This process simplifies parabolic trough plants and improves cost effectiveness by increasing the permissible temperature of the working fluid. In the present work, an innovative DSG plant hybridized with a biomass boiler is proposed and analyzed in detail. Two additional configurations comprising indirect steam generation in parabolic trough collector (PTC) plants were also analyzed in order to compare their energy and exergy performance. In addition, energy and exergy analyses of DSG are conducted and compared to an existing indirect steam generation PTC power plants such as the Andasol. To further understand the biomass subsystem, multiple fuels were presented and analyzed in detail. The obtained results indicate that the proposed DSG-based PTC plant is able to increase the overall system efficiency by 3% in comparison to indirect steam generation when linked to a biomass boiler that supplies 50% of the energy.
Development and analysis of techniques to improve air-cooling and temperature uniformity in battery packs
(2017-08-01) Shahid, Seham; Agelin-Chaab, Martin
One of the challenges to the advancement of electric vehicles is the requirement of an effective thermal management system to maintain the temperature, and temperature uniformity of the battery pack and the cell within the operating limits. In this study, a novel concept has been developed to improve air-cooling and temperature uniformity in a simple battery pack by incorporating inlet plenum, jet inlets, and vortex generators. The proposed battery pack concept reduced the maximum temperature by about 6%. Furthermore, the temperature difference between the maximum temperature and the minimum temperature exhibited by the battery pack was reduced by 24%. Additionally, up to 37% improvement in the temperature uniformity within a single cell was achieved. Moreover, the new concept developed in this study achieved the desired temperature uniformity at the cell level and the pack level to within 5 ºC.
Development and application of an integrated aerodynamic and thermodynamic testing system for cars
(2015-06-01) Abdel-Rahman, Abdalla; Agelin-Chaab, Martin
In this thesis an integrated aerodynamic and thermodynamic testing system was developed. It consists of an incremental force measuring system (FMS) that was designed and constructed. In addition, a testing protocol was developed to integrate aerodynamic and thermodynamic testing in the climatic wind tunnel at UOIT. The FMS was calibrated and used to improve the aerodynamics of four race cars. Furthermore, a thermodynamic test consisting of temperature measurements, and a flow visualization study using tufts were conducted. The aerodynamic study showed that a set of aerodynamic devices can significantly alter the drag force and downforce on cars. However, a little angularity of a device, such as the side front canards, to the flow direction, can significantly alter its function. The flow visualization test showed that the local flow direction strongly depends on the local geometry. The temperature study revealed that the underbody cooling was jeopardized by a rear underbody diffuser.
Development and experimental analysis of a novel hybrid cooling concept for electric vehicle batteries
(2018-03-01) Wei, Yuyang; Agelin-Chaab, Martin
In this thesis, a novel hybrid cooling concept for electric batteries is developed and studied at both the cell-level and pack-level experiments. The concept is based on a simple air-cooling duct that utilizes enhanced water vaporization by convection to achieve an effective cooling. A series of hydrophilic fiber channels containing a water coolant is exposed to a forced air coolant to extract the latent heat from the battery. Air-cooling and water-cooling methods are also studied to compare and prove the cooling performance. From the test results, the hybrid cooling showed a much greater potential for battery packs with higher energy and power density. At the cell level, the contacted hybrid cooling method was able to decrease the highest temperature rise by 82.9%, 69.6%, and 57.3% compared to that of the no-cooling, the air-cooling, and the water-cooling tests, respectively; and the temperature decreased by 60.9% and 47.0% compared to the air- and water-cooling respectively for the contactless hybrid cooling. The maximum cell-level temperature non-uniformity by the contacted and contactless hybrid cooling tests are 4 ℃. and 2℃, respectively. At the pack level, the contactless hybrid cooling provided more than 70% improvement in both the cooling efficiency and the temperature uniformity compared to the no-cooling baseline.
Development and validation of an Active Grille Shutter testing platform
(2020-09-01) Rana, Shaurya; Agelin-Chaab, Martin
In this thesis, a testbench is developed for testing the functionality of Active Grille Shutters (AGS) and radiators in wind tunnels. Additionally, a generic pressure plate is designed to mimic commercial radiators, and a testing procedure is developed for AGS testing. Together, they provide a comprehensive and consistent platform for AGS testing with or without the radiator in a wind tunnel. The platform has been validated using an actual test vehicle in a full-scale wind tunnel. The results show that the testbench produces data consistent with those obtained from the actual test vehicle for validation. Furthermore, leakage characteristics of the testbench were quantified and can be used to replicate the engine bay conditions of any production vehicle.
Development of a method for genetic optimization of aerodynamic devices
(2021-06-01) Lace Aranha, Raphael; Agelin-Chaab, Martin
Driving stability, fuel efficiency and soiling reduction are important for modern vehicles. This thesis has developed a novel method for genetic optimization of aerodynamic devices for road vehicle applications with the objective of minimizing drag and lift. The method involves the integration of genetic algorithms, B-spline shape optimization and computational fluid dynamic using OpenFOAM. The method can generate multiple devices in a single run. It allows the user to decide the objective functions and number of devices to be generated. The method was successfully applied to generate unique device geometries based on the Ahmed body by optimizing the top flap device and bottom diffuser, as well as the combination of the two devices. In addition, advanced vortex identification techniques were applied to the novel aerodynamic devices developed. The study provided physical insight into the drag and lift reduction as well as soiling mitigation mechanisms by the new devices.
Experimental and numerical studies of flows over forward facing steps in pressure gradients
(2016-04-01) Iftekhar, Hassan; Agelin-Chaab, Martin
This thesis reports experimental and numerical studies of the effects of adverse pressure gradients (APG) and Reynolds numbers on flows over forward facing steps (FFS). For the experimental work, particle image velocimetry was used to conduct velocity measurements at several locations downstream of the FFS. Proper orthogonal decomposition and two-point correlation were applied to the experimental data to study the large scale structures. For the numerical analysis, turbulence models in ANSYS Fluent were used to study the reattachment length XL for blockage ratios from 5.8% to 29.5% and step inclination angles from 22.5˚ to 135˚. The experimental results show that XL increases with the increase in Reynolds number without APG, but remains nearly constant for increasing APG. The CFD results show that as the step angle is increased, XL decreased. Furthermore, increasing the blockage at constant Reynolds number, the XL values decrease.
Experimental study of turbulent boundary layer flows over forward facing steps with different surface conditions.
(2014-09-01) Shao, Weijie; Agelin-Chaab, Martin
This thesis is a fundamental study that was conducted experimentally to investigate the effects of different surface types on turbulent flows over forward facing steps. A particle image velocimetry technique was employed to conduct field velocity measurements at the mid-plane of the test channel at selected locations downstream to 68 step heights. Three surface conditions were investigated. A reference smooth acrylic step and two rough steps created using sandpaper 24-grits and 36-grits. Reynolds numbers based on step height and centerline mean velocities of 1200, 3600 and 4800 were employed. The results show that the mean reattachment length increases as Reynolds number increases over the smooth step. However, the mean reattachment length decreases with increasing surface roughness at a given Reynolds number. The mean velocities, Reynolds stresses, triple velocity products and production of Reynolds stresses are used to examine the effects of different surface types on the turbulent characteristics downstream. The results reveal that surface roughness reduced the turbulent quantities in the recirculation and early redevelopment regions. On the other hand, the effects on turbulent flow at downstream locations show no consistent trends. In addition, proper orthogonal decomposition (POD) was used to study the effects of roughness on the large scale structures downstream and to reconstruct flow structure. Results show that low order POD modes can capture up to 90% of the peaks of the Reynolds shear stress profiles using only the first 100 modes. Furthermore, the two-point correlation was employed to quantity the extent of larger scale structures embedded in the flow and how the turbulence is correlated. The results indicate that surface roughness generally decreased the extent of turbulence correlations in both the recirculation and redevelopment regions.
An integrated wind-powered energy system for residential applications in cold regions
(2021-09-01) Addo–Binney, Bismark; Agelin-Chaab, Martin
This thesis proposed an integrated direct wind-powered energy system that can provide drinking water, domestic hot water, space heating as well as electricity for residential applications of a remote community in a cold region. The novelty of the system is that it uses a wind turbine to directly power the heat pump, with the sea water as the evaporator that provides a constant temperature, without the need to use the wind turbine to convert the wind energy to electricity to power the heat pump. Environmental data from the selected location and the Engineering Equation Solver were used to perform the thermodynamic analyses of the system. The results indicate that the proposed system is promising. It is shown that in addition to being more environmentally benign, purchasing a wind turbine is more cost-effective over its lifetime than purchasing electricity from the local grid.
Investigation of a hydrogen production process through aluminum and water chemical reaction
(2019-12-01) Bolt, Andre; Dincer, Ibrahim; Agelin-Chaab, Martin
This thesis reported a novel hydrogen production experimental set up, which utilized the chemical reaction between aluminum and water to produce hydrogen. The constructed experimental setup had an aluminum powder spraying subsystem integrated within the overall setup. The effectiveness of this experimental set up was improved by using a fine size aluminum powder of 149 microns, and nitrogen gas as the medium to facilitate the spraying of the aluminum powder. In order to remove the oxide layer, this thesis study utilized sodium hydroxide as the reaction promoter. The various experimental conditions implemented during the testing process included changes in water temperature and system performance. The criteria used to evaluate system performance were the conversion efficiency, hydrogen production rate and the overall energy and exergy efficiencies. Although the tap water and additional sodium hydroxide displayed better results, seawater achieved a conversion efficiency of 58.8% which can be considered a viable option for future testing.
Optimization of residential buildings and renewable energy integration in small island developing states: the Bahamas as a case study
(2017-08-01) Bingham, Raymond D.; Agelin-Chaab, Martin; Rosen, Marc
An optimization approach is used to assess the energy performance and design of residential homes in The Bahamas with the goal of providing objective data for policy makers to achieve the sustainability goals in the country. EnergyPlus and jEPlus+EA provide the platform for this study, implementing the non-dominated sorting genetic algorithm II (NSGA-II) for optimization. Optimal solutions are compared to a building model developed from audited data. The results indicate that design alternatives presented here can be feasibly implemented that possibly achieve net zero energy and carbon negative status. The peak reduction in life cycle costs is 42%, in building energy consumption is 30%. Additionally, the optimal R-values in the wall and roof constructions vary between 5-15, and 7-25, respectively. It was also shown that tariff rates have little effect on the construction of buildings, but has a larger impact on the integration of photovoltaics and battery storage.
Performance analysis of gas turbine cogeneration systems.
(2014-06-01) Anagal, Ashutosh S.; Reddy, B.V.; Agelin-Chaab, Martin
Cogeneration is a highly efficient approach to generating electricity and process heat from the same fuel source. It is an approach of utilizing waste energy products for a useful purpose that significantly improves the optimal provision of the different grades of energy from high-quality, high-grade electricity or power to low quality and low-grade heat. As a result, combined heat and power can be applied to various situations using various technologies. In the present work, performance of two gas turbine cogeneration systems is analyzed using the first and second laws of thermodynamics. A basic gas turbine cogeneration system and a steam injection gas turbine cogeneration system are investigated. In the analysis the system components, compressor, combustion chamber, turbine and heat recovery steam generator are modeled. The CO2 emissions of both systems are also evaluated. In this investigation the decrease in CO2 emissions was found in the steam injected gas turbine cogeneration system as compared to the basic gas turbine cogeneration system. In the parametric study the influence of pressure ratio and turbine inlet temperature on the performance characteristics of the systems such as specific work, energy and exergy efficiencies are investigated. In the efficiency calculations all the three forms of outputs: power, heat and cogeneration are considered. Thus power generation, heat generation and cogeneration efficiencies are estimated. The carbon dioxide emissions are estimated for both systems. In addition, the effect of pressure ratio and turbine inlet temperature on the CO2 emissions is studied. The results show that pressure ratio and turbine inlet temperature are the key operating variables to optimize the performance of the cogeneration systems. The second law analysis revealed that the maximum exergy destruction occurs in the combustion chamber. In this analysis, the chemical and physical component of the exergy is considered. The role of specific heat as the function of temperature in estimating the performance of cogeneration is also investigated and the performance results are compared with the results assuming constant specific heat. The results with specific heat as the function of temperature are more realistic and accurate compared to the actual performance of the cogeneration systems. The analysis and the results are useful for optimizing the operating parameters of the gas turbine cogeneration systems and thereby enhancing the system performance. The study is also useful for choosing appropriate cogeneration system for a specific application.
A study of a piezoelectric energy harvesting system using magnetorheological fluids
(2020-08-01) Azangbebil, Hayford; Agelin-Chaab, Martin
This thesis reports the study of a piezoelectric energy harvesting system using a thin layer of magnetorheological fluid as a soft impact mechanism to enhance the frequency of the energy generator. Currently, the major bottleneck of vibration energy harvesting is the dynamic nature of vibrations in the environment which necessitates that vibration energy harvesters change their frequency to match that of the source. This work used the variable rheological properties of magnetorheological fluids to tune the frequency of a piezoelectric energy harvester. The study employed both numerical and experimental studies to investigate the effect of using the fluid in vibration energy harvesting. The results obtained show an increase in the output voltage and frequency of the device by 9.7% and 36%, respectively. For the first time, a soft impact frequency-increased piezoelectric energy harvesting system using magnetorheological fluid is studied in this thesis.

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Browsing Master Theses & Projects (FEAS) by Author "Agelin-Chaab, Martin"