Implementing multicomponent diffusion in numerical combustion studies is computationally expensive due to the challenges involved in computing diffusion coefficients. As a result, mixture-averaged diffusion treatments or simpler methods are used to avoid these costs. However, the accuracy and appropriateness of the mixture-averaged diffusion model has not been verified for three-dimensional...
Heat flux measurements of radiation emissions from turbulent premixed flames diluted with N 2 and CO 2 were taken to identify sensitivities of radiation heat loss to diluent fraction and species. This work is motivated by the desire to better characterise radiant heat transfer in the presence of combustion products,...
Digital Human Modeling (DHM) is a computational design tool that allows designers to use virtual prototypes of design for exploring ergonomics requirements. DHM brings in the advantage of reducing the time and finances committed to building the physical prototypes as well as minimizing the efforts put on performing human subject...
Topology optimization (TO) is a mathematical method to find the optimal size, shape and connectivity of a domain under specified conditions, and has had many applications in engineering design. However, challenges remain in realizing TO as an effective design tool for many design situations. Uncertainty is ubiquitous in nature and...
This dissertation details the application of digital image correlation (DIC) in novel methods for mechanical testing and shape characterization. The first usage manifested in the development of a novel composite test specimen that provided the ability to characterize the matrix compression energy release rate at initiation and subsequent crack propagation....
The behavior of the thin liquid film formed between a bubble and hydrophobic membrane is of high interest in applications where separating two-phase mixtures is beneficial. One such application is in-situ vapor extraction heat sinks. In these systems, high heat transfer rates are accomplished by taking advantage of the high...
The orb web is a multipurpose structure---serving as a home for its inhabitant spider, as a prey capture device, and as a physical extension of the spider’s sensing abilities. Biologists are particularly interested in the spider’s ability to locate prey trapped in its web by sensing the vibrations induced from...
The rising global trend to reduce dependence on fossil fuels has provided significant motivation toward the development of alternative energy conversion methods and new technologies to improve their efficiency. Recently, oscillating energy harvesters have shown promise as highly efficient and scalable turbines, which can be implemented in areas where traditional...
Microchannel high temperature recuperators have the advantage of higher heat transfer coefficients and lower size and weight than traditional high temperature recuperators. However, the industrial application of microchannel recuperators are restricted by the high cost of photochemical machining and diffusion bonding. The objective of this paper is to introduce a...
In order to solve some classic problems in traditional topology optimization, such as unknown material distribution, checker-boarding and curse of dimensionality, this thesis introduces a new method to construct a mechanical structure that can reduce mass and increase stiffness. It uses a graph to represent the skeleton of a structure....
The SpiderHarp is a bio-inspired electronic musical instrument that uses a localization algorithm developed at Oregon State University to translate plucks of its strings into musical notes. This localization algorithm was inspired by the way spiders locate prey in their webs. The SpiderHarp frame, sensors, and web design are also...
This thesis presents accurate and time-optimal smooth reference trajectory generation techniques for manufacturing equipment such as high-speed machine tools (MT) and industrial robots (IR). Typical machining tool-paths for MTs and IRs are defined as a series of discrete linear moves. Although Point-to-Point (P2P) feed motion can be generated by interpolating...
The aviation industry is pushing for better fuels and gas turbine engines for several reasons: cost, emissions, and to a lesser extent high-altitude relights. One aspect that research has been focused on to help reduce costs, emissions and better understand high-altitude relights is studying the combustion behavior of the fuel...
To investigate the melting stage of indirect freeze desalination three numerical models were developed. A zeroth, first, and second order analyses modeled the melting of ice around the outside of a pipe as a function of time. The zeroth order analysis assumes the system to be steady state. The first...
Controllers for robotic systems can be complex and difficult to write by hand. Learning offers an approach to improve a controller through direct feedback. Learning is not trivial, as the feedback does not tell the agent how to improve, only how well its current actions solve the given task. Learning...
Breakthroughs in heat sink design are now limited by conventional manufacturing techniques which can only produce basic fin shapes with homogenous surface structuring. Additive Manufacturing (AM) is a potential disruptive technology for heat sink design and other convective heat transfer solutions, as surface properties can be directionally varied to maximize...
This research presents a methodology to identify and analyze human-system interactions, and their potential failure modes using a functional decomposition approach during the early system design stage.
The fundamental research contribution of this work is the development of a framework to identify associations between physical user-product interactions, generic human errors...
Modern product development is a complex combination of multidisciplinary processes ranging from market research to design, engineering analysis, and logistics. The product development process has a significant impact on the success or failure of new product launches. The majority of consumer product launches fail, resulting in significant sunk cost in...
The leading edge of a sub-orbital, sounding rocket dictates an aerodynamically optimal profile which is difficult to manufacture. The university level offers no current standard to produce rocket nose cones made with pre-impregnated composites. Of particular interest is the molding technique used to fabricate a nose cone. The focus of...
In a seminal paper published in 1982, scientist have warned that humanity was pushing earth’s ecosystems beyond their capacities to support the web of life. One response to the concern was outlined by NASA with its vision for advanced fixed wing transport aircraft to be environmentally compatible and have revolutionary...
The fuzzy front end of engineering design can present a difficult challenge, and as such, recent engineering design research has focused on guiding and influencing the way a designer ideates. Early ideation can be especially difficult when attempting to integrate specific design objectives in product design, called Design for X...
Unmanned Aerial System (UAS) technology is a rapidly developing technological marketspace. This thesis focuses on micro, tethered, coaxial UASs and the development of an electrically-tethered observation platform (ETOP). The thesis details the current status of the technology as well as current products on the market. Stability considerations, critical when adding...
Legged robots, while advancing quickly, have far to go before they can recover from major disturbances safely and consistently. Reflected inertia, which affects how quickly the actuators can physically respond to an environmental disturbance, and delay, which describes the time necessary for the controller to sense, re-plan, and respond to...
As CAD tools become more sophisticated, engineers are able to more easily create complex part geometries with minimal mass given strength and stiffness requirements. However, these complex part geometries can be difficult to subtractively manufacture, which consequently increases manufacturing cost and production time. This thesis presents a method independent of...
For the 2019 season, a new chassis layup was designed that is much stronger than in previous years, yet only slightly heavier. Compared to the baseline steel tube frame, the 2019 chassis has safety factors of about 110% for most zones. Also, a new impact attenuator was designed that absorbs...
With the widespread replacement of aluminum with composite materials, particularly in aircraft structures, the lack of comprehensive understanding of these materials is unsettling. The complex nature of these materials, with respect to isotropic aluminum, makes the prediction of their mechanical response equally complex. The failure of carbon fiber reinforced plastic...
Clean cooking technologies and fuels have been cited as a viable way to slow climate change and reduce the health and environmental impacts associated with traditional cooking devices used by 40% of the world. While engineers in the Design for Development sector have created hundreds of stove designs that perform...
Clean technologies can address multiple challenges associated with climate change, environmental protection, and human health. However, the impact desired by introduction of such technologies is achievable only if new options effectively replace inefficient, conventional practices. This ‘design for adoption’ requires understanding of user motivations, associated beliefs, context of use, and...
Selective laser melting (SLM) is an additive manufacturing (AM) process that uses a laser beam to melt metal powder as it is spread onto the build surface using a roller or scraper, followed by rapid solidification to manufacture a 3D component, one layer at a time.
In SLM process, density...
The unsustainable use of fresh water sources and unavailability of fresh water in certain parts of the world have created a demand for water desalination systems. Desalination methods are effective at producing consumable water, but often require large scale setups, high energy consumption, and careful maintenance. A team of students...
This work develops the Global Formula Racing computational fluid dynamics (CFD) model in StarCCM+ to allow for vehicle attitude studies to be ran to evaluate Formula Student (FS) vehicle aerodynamic loads. Attitudes that this model allows to be studied include roll, pitch, yaw, heave, tire angle, and vehicle speed. The...
The current knowledge on the microstructural evolutions and mechanical properties of selective laser melting (SLM) produced H13 tool steel components is limited. This research is focused on optimization of SLM processing parameters for H13 tool steel and investigation of microstructure and mechanical properties of H13 tool steel components after SLM...
Freeze desalination poses as a potential solution to many of the issues that accompany current desalination methods. The research detailed in this manuscript involves creating and analyzing a numerical model of the freezing operation of an indirect contact freeze-melting (FM) desalination system. In this initial analysis, pure water is frozen...
The purpose of this report is to detail the design and validation of a prototype robot that feeds biomass into a range of small household cookstoves at a programmable rate. Improved design and testing methods for the development of improved biomass cookstoves are needed to design stoves that alleviate the...
Energy from offshore wind could provide substantial power generation if further utilized. One area of significant research focus is in developing floating offshore wind devices, which would allow for wind energy to be gathered in deep water where driven monopile turbines are infeasible. However, floating offshore wind is not currently...
Marching band activities consist of both physically and cognitively demanding tasks. The demands that this activity has on players has largely been unstudied. The goal of this study was to investigate the effects of players’ experience level, role, and gender on the workload of marching band players via a field...
Vortical structures are the driving mechanism of transition to turbulence in porous media requiring adequately resolved observations along with analysis of the scale and energy of flow within the pores. Of specific interest is to understand the vortex dynamics, energy, and turbulent mixing and transport properties in the scale of...
As carbon emissions are negatively impacting ecosystems across the globe, researchers are in a race against time to provide cleaner and more eÿcient power. Detonation engines can help meet the increasing demands for cleaner and more eÿcient power generation by providing an alternative means to use oxy-fuel combustion for carbon...
Gasoline direct injection engines, with downsized boosted technology, present a promising option for enhancing power density and reducing fuel consumption for next-generation engine designs to meet stringent fuel economy and emission standards. However, these developments in the low-speed and high-load operating regime are challenged by the occurrence of a new...
Spot fires caused by lofted embers (i.e., firebrands) can be a significant factor in the spread of wildland fires. Embers can be especially dangerous near the wildland-urban interface (WUI) because of the potential for the fire to be spread near or on structures. Many studies have investigated the transport of...
Improving the coexistence of eagles and wind energy is a critical effort for the sustainable expansion of the wind energy sector. Information about eagle activity and interactions with wind turbines enables verification of deterrence methods. This information can be broken into two categories: eagle activity in the airspace around wind...
Force data for a flapping foil energy harvester with active leading edge motion operating in the low reduced frequency range is collected to determine how leading edge motion affects energy harvesting performance. The foil pivots about the midchord and operates in the low reduced frequency range of 0.06, 0.08, and...
Airborne Wind Energy System (AWES) are quickly coming to fruition, with increased energy production while reducing the cost of implementation and materials. This thesis develops a new computational model for a tethered AWES and characterizes a new rapid prototyping method with the objective of supporting the design and rapid prototyping...
Porous media are the materials containing void space or pores, where fluids and gases can pass through. Unsteady flows in porous media are encountered in many engineering applications and natural problems, such as CO₂ sequestration, high temperature nuclear reactor cooling, high efficiency combustion, chemical reactors, noise reduction on airplane trailing...
In order to enable better visualization and understanding of the effect of the robot's geometry and inertia on the robot's trajectories, this dissertation proposes to use geometric mechanics to bridge the gap between the physical motion of a robot and its mathematical structure. The main focus of this research is...
Single Point Incremental Forming (SPIF) is a forming process in which a fully clamped sheet is formed by a hemispherical ended tool that moves along a predefined 3D toolpath. The sheet is formed in a series of local deformations to reach its desired shape. Double Sided Incremental Forming (DSIF) includes...
This research seeks to identify how changes in temperature and oxygen concentration in the reaction zone affects liftoff heights for moderate or intense low-oxygen dilution (MILD) combustion of a jet fuel and a surrogate fuel. MILD combustion offers a method of burning fuels with reduced CO and NOx production by...
The Oregon State University (OSU) Experimental Sounding Rocket Association (ESRA) 30k Rocket Team is a student run rocket team that competes in the Intercollegiate Rocket Engineering Competition at Spaceport America. The goal of the competition is to launch a student designed, manufactured, and tested experimental sounding rocket to 30,000 ft...
Prediction and mitigation of chatter vibrations in machining operations and optimizing overall machining mechanics are crucial for achieving greater productivity and manufacturing efficiency. This thesis first explores effect of directional relationships on chatter stability in milling process. Based on the directional relationships, a geometry-based chatter stability index (CSI) is proposed...
Recent advancements in joining operations and additive manufacturing now allow complex metal parts to be built up from raw materials, as opposed to being machined down from solid blocks. This not only opens up the design space, but also allows for much more efficient manufacturing. By decomposing a complex part...