Browsing by Author "Bandhauer, Todd M., committee member"

Now showing 1 - 4 of 4

Open Access
Evaluation of power-assist hydraulic and electric hybrids for medium- and heavy-duty vehicle applications
(Colorado State University. Libraries, 2014) Wagner, Justin Taylor, author; Bradley, Thomas H., advisor; Bandhauer, Todd M., committee member; Sega, Ronald M., committee member
Under pressure from rising fuel costs, emissions constraints, and new government regulations on medium- and heavy-duty vehicles, hybrid technologies for these classes of vehicles are becoming more prevalent. A variety of technologies have been proposed to meet these requirements including power-assist hybrid electric and hybrid hydraulic systems. Although there has been great discussion about the benefits surrounding each of the technologies individually, no direct comparisons are available on the basis of economics and fuel economy. This study focuses on comparing these power-assist technologies on these bases as well as determines the ability of these technologies to fulfill the newly adopted fuel economy regulations. In order to accomplish this goal, three computational models of vehicle dynamics, thermal behavior and fuel economy were created and validated to simulate the conventional vehicle and hydraulic and electric hybrids. These models were simulated over the Heavy-Duty Urban Dynamometer Driving Schedule, the HTUF Class 4 Parcel Delivery Cycle, and the Orange County Bus cycle. These drive cycles were chosen on their ability to characterize the variety of operating conditions observed in medium- and heavy-duty vehicles. Using these models, cross technology comparisons were constructed comparing commercially available systems, systems with a fixed mass, and systems with a fixed incremental cost. The results of the commercially available systems showed that the Azure Dynamics HEV provided greater fuel economy improvement than the Lightning Hybrids HHV for drive cycle kinetic intensities less than 3.19 miles-1. Although this system showed a cost of fuel savings over the HHV, it was seen that the incremental cost of the HEV exceeded the cost of fuel savings over the HHV. The fixed mass comparison case, which compared vehicles with equal cargo carrying utility, showed similar results to that of the commercially available case. Although the increase in incremental cost for the varying HEV systems designed for the fixed mass case correlated to an improvement in fuel savings, the cost associated with the systems surpassed the savings seen. Lastly, the fixed cost case provided results which were also similar to the commercially available case. Due to the fixed system cost, it was seen that for these systems, the fuel economy benefits and associated cost showed the greatest benefits for the HEV. This study concluded that given the evaluation, the HEV was the only power-assist hybrid technology which could fulfill the regulated fuel economy improvement of 15%. Although the HEV was the only technology which could fulfill the requirements, the HHV showed an improvement upwards of 7% greater than the HEV for the Orange County Bus Drive Cycle.
Open Access
Financial and environmental impacts of new technologies in the energy sector
(Colorado State University. Libraries, 2015) Duthu, Ray C., III, author; Bradley, Thomas H., advisor; Bandhauer, Todd M., committee member; Carlson, Kenneth H., committee member; Suryanarayanan, Siddharth, committee member
Energy industries (generation, transmission and distribution of fuels and electricity) have a long history as the key elements of the US energy economy and have operated within a mostly consistent niche in our society for the past century. However, varieties of interrelated drivers are forcing changes to these industries’ business practices, relationship to their customers, and function in society. In the electric utility industry, the customer is moving towards acting as a fuller partner in the energy economy: buying, selling, and dispatching its demand according to its own incentives. Natural gas exploration and production has long operated out in rural areas farther from public concerns or regulations, but now, due to hydraulic fracturing, new exploration is occurring in more urbanized, developed regions of the country and is creating significant public concern. For these industries, the challenges to their economic development and to improvements to the energy sector are not necessarily technological; but are social, business, and policy problems. This dissertation seeks to understand and design towards these issues by building economic and life cycle assessment models that quantify value, potential monetization, and the potential difference between the monetization and value for two new technologies: customer-owned distributed generation systems and integrated development plans with pipeline water transport in hydraulically fractured oil and gas fields. An inclusive business model of a generic customer in Fort Collins, Co and its surrounding utilities demonstrates that traditional utility rates provide customers with incentives that encourage over-monetization of a customer’s distributed generation resource at the expense of the utilities. Another model which compares customer behavior incented by traditional rates in three New England cities with the behavior incented through a real-time pricing market corroborates this conclusion. Daily customer load peak-shaving is shown to have a negligible and unreliable value in reducing the average cost of electricity and in some cases can increase these costs. These models support the hypothesis that distributed generation systems provide much greater value when operated during a few significant electricity price events than according to a daily cycle. New business practices which foster greater cooperation between customers and utilities, such as a real-time price market with a higher fidelity price signal, reconnect distributed generation’s potential monetization to its value in the marketplace. These new business models are required to ensure that these new technologies are integrated into the electric grid and into the energy market in such a way that all of the market participants are interested and invested stakeholders. The truck transport of water associated with hydraulic fracturing creates significant local costs. A life cycle analysis of a hypothetical oil and gas field generic to the northern Colorado Denver-Julesburg basin quantifies the economic, environmental, and social costs associated with truck transport and compares these results with water pipeline systems. A literature review of incident data demonstrates that pipelines historically have spilled less hazardous material and caused fewer injuries and fatalities than truck transport systems. The life cycle analysis demonstrates that pipeline systems also emit less pollutants and cause less local road damage than comparable trucking systems. Pipeline systems are shown to be superior to trucking systems across all the metrics considered in this project. In each of these domains, this research has developed expanded-scope models of these new technologies and systems to quantify the tradeoffs that are present between monetization, environment, and economic value. The results point towards those business models, policies, and management practices that enable the development of more equitable, efficient, and sustainable energy systems.
Open Access
Insight into alternative battery technologies using 3D configurations, protective coatings, and characterization of resistive properties
(Colorado State University. Libraries, 2025) Windsor, Daniel S., author; Prieto, Amy L., advisor; Neilson, James R., committee member; Shores, Matthew P., committee member; Bandhauer, Todd M., committee member
The omni presence of lithium-ion batteries (LIBs) have revolutionized the modern world due to this technology's implementation as an energy storage device in smart phones, wearable electronics, and electric vehicles. Lithium-ion batteries are well suited for these applications owing to the light weight of these systems and their ability to store a large amount of charge. For these reasons, LIBs are classified as energy dense systems, which describes the amount of energy a technology can store per unit mass. A battery metric where LIBs struggle in terms of performance is power density, or the amount of power a technology can produce per unit mass. These systems, also, require expensive feedstock materials that are geographically isolated which has profound impacts on economics and supply chain considerations for LIBs. Thus, if rechargeable batteries are to continue to advance, alternative battery configurations and chemistries must be studied. Chapter 1 describes the field of LIBs, in terms of the advantages and disadvantages of this technology. This discussion is followed by brief mentions of some of the champion materials found in the anodes, cathodes, and electrolytes currently implemented in LIBs. The discussion on the champion materials for LIBs also covers the drawbacks of each material, and ways in which future investigations can improve their performance. This is then followed by a section which highlights how alternative battery configurations and chemistries can address some of the inherent disadvantages of the LIBs system. This chapter concludes with a discussion on some important soft skills the author learned during the completion of this degree. Chapter 2 covers the development and advances made in the field of 3D batteries. This chapter begins with an introduction of the 3D battery field and includes a section which discusses the current advances made in the literature. This is then followed by a discussion on the computational advances made in the field of 3D batteries, where there is a critical need to develop digital twins of 3D batteries to better understand the chemo-mechanical dynamics of these complex systems. The following portion of this chapter covers the development of 3D batteries through the lens of critical performance metrics, being power density, energy density, and cyclability and scalability. For 3D batteries, this chapter identified that improvements in energy density is the area where further advances are most needed. Finally, this chapter discuss efforts being made in industry toward the commercialization of these 3D battery systems. Chapter 3 covers an investigation into the fundamental effect of a polymer protective coating, cyclized-polyacrylonitrile (cPAN), on the Na-ion (de)insertion chemistry of antimony-based anodes in sodium-ion batteries (NIBs). This investigation was able to determine that the cPAN coating had the most pronounced effect on the early cycle (cycles 1-10) Na-ion (de)insertion chemistry of the antimony-based anodes. The interfacial resistance was, also, diminished by the presence of the cPAN protective layer which implies that the cPAN helps to facilitate Na-ion transport at the electrode-electrolyte interface. Chapter 4 discusses a practical and beginners' approach to the learning electrochemical impedance spectroscopy (EIS) for rechargeable batteries. This chapter begins with a simple deconvolution of the EIS acronym, such that the reader has a deeper understanding of how each component of the acronym combines to create this technique. The chapter continues by discussing how to preform both qualitative and quantitative EIS analyses on rechargeable batteries, and finishes with a discussion on the EIS specifics of rechargeable battery systems. Chapter 5 covers the future areas in which the work presented in Chapter 3 can be extended. In particular this chapter discusses the critical need to quantify the SEI products of a cPAN coated antimony electrode, as early cycle numbers, and ways in which cPAN can be applied to high surface area substrates to ideally formulate a 3D sodium-ion battery.
Open Access
Tailoring solid-liquid interactions to control droplet wetting and dynamics
(Colorado State University. Libraries, 2019) Vahabi, Hamed, author; Kota, Arun K., advisor; Dasi, Lakshmi Prasad, committee member; Tavener, Simon, committee member; Bandhauer, Todd M., committee member
Recent advances in micro/nano-scale fabrication techniques and synthesis of novel chemicals with a variety of functionalities have opened up new avenues in tailoring solid-liquid interactions. In this work, by systematically tuning the wettability and slipperiness of solid surfaces, we developed a multitude of novel surfaces and strategies. First, we developed metamorphic superomniphobic surfaces that display wetting transition in response to heat. Second, we systematically studied the dynamics of droplets of various liquids during coalescence-induced jumping on textured super-repellent surfaces. Third, we developed a simple and passive strategy consisting of superomniphobic surfaces with a protruding macrotexture to demonstrate coalescence-induced jumping with significantly higher energy conversion efficiency, compared to state-of-the-art surfaces. Fourth, we developed a simple "grafting to" technique to fabricate a novel non-textured hydrophilic surface that is counterintuitively slippery with unprecedented potential to enhance the heat transfer coefficient in dropwise condensation. Fifth, we developed a novel triboelectric-based droplet manipulation technique on smooth hydrophobic slippery surfaces that is very simple without any complex fabrication of manipulation platform or expensive actuation system. Overall, the novel surfaces and strategies developed in this work have significant implications for phase-change heat transfer, liquid transportation, anti-fouling, self-cleaning, drag reduction, corrosion control, and manipulation of liquid droplets.