Index Catalog // ScholarsArchive@OSU

A product development process measurement methodology applied to small manufacturing companies

Creator:: Schlegel, Stephen C.
Abstract:: The implementation of concurrent engineering into many large companies has greatly improved their product development processes. These companies have seen significant gains in quality and customer satisfaction with reduced product costs, defects, and time-to-market (Lake, 1992). Many large companies have successfully employed this relatively new product development philosophy. However, smaller...
Resource Type:: Masters Thesis

Effects of orifice geometry and surface boundary condition on heat transfer of impinging jet array

Creator:: Kanokjaruvijit, Koonlaya.
Abstract:: The effects of the orifice geometry and the surface boundary condition on the heat transfer distribution to a flat surface of an impinging jet array were investigated. The jet array impinged normally onto the surface which was either isothermal or had a uniform heat flux. The experiments were performed for...
Resource Type:: Masters Thesis

An experimental study of fluid flow and heat transfer in rectangular microchannels

Creator:: Popescu, Aristotel
Resource Type:: Dissertation

A numerical study of the response of Lake Kinneret to wind forcing

Creator:: Vernieres, Guillaume
Abstract:: Lake Kinneret is Israel's only fresh water lake (unless you count the Dead Sea). It spans roughly 20km from north to south, and about 12km at its widest east west extent. It is not quite 50m deep at its deepest point. In late spring, the lake stratifies significantly and remains...
Resource Type:: Masters Thesis

Diagnostic analysis for mechanical systems

Creator:: Henning, Scott A.
Abstract:: An analysis and modeling method of the diagnostic characteristics of a mechanical or electromechanical system is presented. Diagnosability analysis is especially relevant given the complexities and functional interdependencies of modern-day systems, since improvements in diagnosability can lead to a reduction of a system's life-cycle costs. The diagnosis process of a...
Resource Type:: Masters Thesis

Robust lateral pulse jet control of an atmospheric rocket

Creator:: Burchett, Bradley Thomas
Abstract:: Uncontrolled direct fire rockets exhibit high impact point dispersion, even at relatively short range, and as such have been employed as area weapons on the battlefield. In order to reduce the dispersion of a direct fire rocket, feedback control is employed to fire short-duration solid rocket pulses mounted near the...
Resource Type:: Dissertation

Incorporating uncertainty into diagnostic analysis of mechanical systems

Creator:: Mocko, Gregory M.
Abstract:: Analyzing systems during the conceptual stages of design for characteristics essential to the ease of fault diagnosis is important in today's mechanical systems because consumers and manufacturers are becoming increasingly concerned with cost incurred over the life cycle of the system. The increase in complexity of modem mechanical systems can...
Resource Type:: Masters Thesis

Computer aided model generation for high performance dynamometers

Creator:: Ko, Seung-uk
Abstract:: A model has been developed for accurate emulation of the complex behavior of high performance dynamometers used in a broad range of applications including manufacturing systems, biomechanics research, and crash testing. The key objective of this research has been to reach the proper balance between the accuracy of emulation and...
Resource Type:: Masters Thesis

A study of the characteristics of oscillatory surface instabilities leading to droplet formation

Creator:: Daniels, Brian J.
Abstract:: The characteristics of the free surface in an orifice driven by a periodic forcing function have been studied both theoretically and experimentally. In the theoretical study, two wall boundary condition cases were examined: 1) the radial velocity at the wall of the orifice is zero; and 2) the axial velocity...
Resource Type:: Masters Thesis

Flow characteristics of semi-confined impinging jet arrays

Creator:: Dano, Bertrand P. E.
Abstract:: The present study proposes to investigate the flow structure of different arrays of jets impinging on a flat surface enclosed by three walls, creating a channel that forces the air to leave in one preferential direction, generating a self sustain crossflow. Details of both the mean and some turbulence quantities...
Resource Type:: Masters Thesis

Operation and maintenance procedures for improving compressed air system efficiency

Creator:: Bessey, Eric G.
Abstract:: Air compressors are a significant industrial energy user and therefore a prime target for industrial energy audits. The project goals were to develop a software tool, AIRMaster, develop a methodology for performing compressed air system audits, and conduct field audits to refine the methodology and assess savings potential from six...
Resource Type:: Masters Thesis

Flow characteristics of co-flowing, laminar streams in a rectangular microchannel

Creator:: Oak, Jason
Abstract:: The effects of varying flow rate ratio and Reynolds number on the momentum diffusion and flow development of two co-flowing, laminar streams in a rectangular microchannel are presented. The microchannel has an aspect ratio of approximately 16 with a width of 1006 μm and a height of 63 μm. A...
Resource Type:: Masters Thesis

Processing bulk metallic glass from the molten state

Creator:: McCracken, Ivan A.
Abstract:: This paper documents the investigation into injection molding, or die casting, a bulk metallic glass (BMG). A BMG is an amorphous metal of a thickness greater than 25 μm, according to leading researchers in the field. This critical thickness differentiates a normal metallic glass from a "bulk" metallic glass. The...
Resource Type:: Masters Thesis

Laminar natural convection within long vertical uniformly heated parallel-plate channels and circular tubes

Creator:: Vorayos, Nat
Abstract:: The problem of simple mathematical models of laminar natural convective flow within a long vertical parallel-plate channels and circular tubes kept at uniformly heated walls is revisited to seek a clear physical understanding of heat transfer mechanisms. A series solution method to analyze the fully developed flow and an integral...
Resource Type:: Dissertation

Metallurgy and superconductivity of niobium-titanium-tantalum ternary alloy systems

Creator:: Li, Na
Abstract:: The metallurgy and superconductivity of the Nb-Ti-Ta ternary alloy system were studied. The Nb-Ti, and Ta-Ti binary samples, and Nb-Ti-Ta ternary samples were precipitation heat treated under different schedules. After the precipitating heat treatment, the samples were characterized by X-Ray Diffraction (XRD) techniques. Equilibrium binary and ternary phase diagrams based...
Resource Type:: Masters Thesis

Lateral pulse jet control of a direct fire atmospheric rocket using an inertial measurement unit sensor system

Creator:: Jitpraphai, Thanat
Abstract:: Impact point dispersion of a direct fire rocket can be drastically reduced with a ring of appropriately sized lateral pulse jets coupled to a trajectory tracking flight control system. The system is shown to work well against uncertainty in the form of initial off-axis angular velocity perturbations as well as...
Resource Type:: Dissertation

Laminate mixing in microscale fractal-like merging channel networks

Creator:: Enfield, Kent E.
Abstract:: A two-dimensional model was developed to predict concentration profiles from passive, laminar mixing of concentration layers formed in a fractal-like merging channel network. Both flat and parabolic velocity profiles were used in the model. A physical experiment was used to confirm the results of the model. Concentration profiles were acquired...
Resource Type:: Masters Thesis

Functional imaging reveals modest strain concentrations associated with implant micromotion using modified BAK interbody cages

Creator:: Berry, Daniel J.
Abstract:: Interbody fusion cages are increasingly used in the treatment of spinal disease and injury in order to stabilize movement and promote arthrodesis of the vertebral bodies, but the micro-mechanics of the interaction between the cage and the adjacent host bone is not fully understood. This information has bearing on post-surgical...
Resource Type:: Masters Thesis

Performance of a smart direct fire penetrator using a ram air controlled mechanism

Creator:: Chandgadkar, Siddharth Suhaschandra
Abstract:: The effectiveness of a direct fire penetrator projectile equipped with an actively controlled ram air mechanism is investigated through dynamic simulation. The ram air control mechanism consists of a rotary sleeve valve which directs air flow from an inlet at the center of the nose to side ports. The projectile...
Resource Type:: Masters Thesis

Elastic, plastic, and total strains in human and porcine pedicle trabecular bone and PU-foam after pedicle screw insertion by utilizing functional micro-CT imaging

Creator:: Moran, Sean T.
Abstract:: Pedicle screw breakage and loosening remain as clinical complications of short segment instrumentation procedures for spinal stabilization. This study has directly visualized and measured elastic, plastic and total vertebral pedicle trabecular bone full-field strains in the regions immediately surrounding the pedicle screw during pedicle screw insertion by utilizing functional microCT...
Resource Type:: Masters Thesis

Quantitative comparison of full field strains experimentally measured and analytically predicted for aluminum foams

Creator:: Rutschman, Scott A.
Abstract:: Metallic foams have become widely available and have unique properties that make them attractive for use in a variety of engineering applications. Due to their complex structure, the behavior of foams under complex loading conditions is a subject of continued research. Digital volume correlation is a technique wherein full-field strains...
Resource Type:: Masters Thesis

Design, modeling and performance of miniature reciprocating expander for a heat actuated heat pump

Creator:: Herron, Thomas G.
Abstract:: A miniature reciprocating expander is being developed as part of a larger program to develop a heat actuated heat pump for portable applications. By utilizing the higher energy density of liquid hydrocarbon fuels relative to batteries, a heat actuated heat pump would be able to provide cooling for much longer...
Resource Type:: Masters Thesis

The effects of pulsing and blowing ratio on a 45° inclined jet in cross flow

Creator:: Stander, Arjan
Abstract:: The effect of jet flow pulsing and blowing ratio on a jet in cross flow has been investigated. Preliminary jet flow studies were performed without cross flow and an extensive study of jet with cross flow was done for a total of nine test cases. The effect of velocities ratios...
Resource Type:: Masters Thesis

A study of cavitation instabilities in solids

Creator:: Puttapitukporn, Tumrong
Abstract:: Cavitation instabilities in elastic-plastic solids under spherically-symmetric and axisymmetric loadings were investigated using the finite element method. Both quasi-static and dynamic analyses were used to solve these problems. In the quasi-static analyses, we investigated a cavitation instability in elastic/perfectly-plastic, linear hardening elastic-plastic, power hardening elasticplastic, and constrained silver materials. Here,...
Resource Type:: Dissertation

A study of solidification dynamics with liquid mass influx

Creator:: Thirunavukarasu, Balamurugesh
Abstract:: A computational model is developed to study the effects of alumina layer formation on an ablative surface when exposed to high temperature particle laden gas flow. The solidification dynamics i.e., the solid and liquid alumina layer growth rate, and the heat transferred to the ablative surface are investigated. A one-dimensional...
Resource Type:: Masters Thesis

Flow induced mixing in high aspect ratio microchannels

Creator:: Siripoorikan, Bunchong
Abstract:: Micro-fluid mixing is an important aspect of many of the various micro-fluidic systems used in biochemical production, biomedical industries, micro-energy systems and some electronic devices. Typically, because of size constraints and laminar flow conditions, different fluids may only have the opportunity to mix by diffusion, which is extremely rate limited....
Resource Type:: Masters Thesis

A numerical model of drop-on demand droplet formation from a vibrating nozzle and a rigid nozzle

Creator:: Yang, Guozhong
Abstract:: Droplet formation from a rigid and a vibration nozzle driven by a pulsing pressure is simulated. Droplet formation is simulated by using one-dimensional model. For the case of droplet formation from a vibration nozzle, the nozzle vibration is simulated by large deflection plate vibration equation. Droplet formation from a rigid...
Resource Type:: Masters Thesis

Solutions of plate equation for the prediction of ink droplets in inkjet cartridges

Creator:: Sangplung, Saangrut
Abstract:: Droplet formation in inkjet cartridges has been studied for several decades to improve print qualities. Currents and rigid nozzle plates are used inside the cartridge to fix the size of droplets exiting the chamber. This research is focused on studying the effect of nozzle flexibility on droplet formation. A flexible...
Resource Type:: Masters Thesis

Optimal troubleshooting plan for a complex electro-mechanical system

Creator:: Durgi, Parthsarathy
Abstract:: The decision sequences used for troubleshooting of complex electro-mechanical systems are often ad hoc and less than optimal. This research investigated Decision Analysis and Bayesian Networks for generating an optimal decision sequence for troubleshooting. The model that was used in this research was the bleed air control system of the...
Resource Type:: Masters Thesis

Investigation of the dimensional stability of an ultra-thin film gas/liquid contactor

Creator:: Peterson, Jerrod P.
Abstract:: The use of a permeable membrane to mechanically constrain a film of water with an area of 12 cm² and a thickness of 150 μm in a gas/liquid contactor was investigated. The membrane separated the vapor and liquid phases, and a stiffener plate made from a gas-permeable material was used...
Resource Type:: Masters Thesis

Dynamic modeling, control and linear theory of a projectile equipped with a rotating internal part

Creator:: Frost, Geoffrey W.
Abstract:: Dynamic modeling of the atmospheric flight mechanics of a projectile equipped with an uncontrolled internal rotating disk is investigated and a modified projectile linear theory is established. It is shown through modeling of this type of projectile that several coefficients of the epicyclic dynamics are altered, leading to changes in...
Resource Type:: Dissertation

Quality driven collaborative decision making for product development under the influence of trustworthiness

Creator:: Meier, Stefan
Abstract:: The focus of this study is the effective prioritization of customer requirements in collaborative product development. The CR priorities are often retrieved by questioning and interviewing targeted customers. But the targeted customer might not always be easily questioned, because they might not always be obvious or clearly known. If customers...
Resource Type:: Masters Thesis

A force plate for measuring contact forces during dependent transfers onboard aircraft

Creator:: Schafer, Christopher A.
Abstract:: The transfer of air travelers with disabilities between a mobility aid and an aircraft seat is a major source of injury for both the travelers and the airline personnel assisting in the transfer. The risk to both parties might be reduced through the biomechanical study of the transfer task. Such...
Resource Type:: Masters Thesis

An exploration of microcombustor feasibility

Creator:: Hatfield, Jonathan M.
Abstract:: The goals of this research were first to examine flame quenching in tubing smaller than the quench diameter, and then to place lower size limits on microcombustor and microreactor systems by studying a catalytic microcombustor burning propane. In the first set of experiments, flame quenching was examined as a function...
Resource Type:: Masters Thesis

A study of micro-scale, fractal-like branching flow networks for reduced pumping power and improved temperature uniformity

Creator:: Alharbi, Ali Y.
Abstract:: A first generation, one-dimensional predictive model is proposed for designing heat sinks with fractal flow networks. A three-dimensional computational fluid dynamics (CFD) model is analyzed as a means for validating the model and identifying areas for improvement. Two separate CFD models were developed. One was analyzed with conjugate heat transfer...
Resource Type:: Masters Thesis

Large-strain softening of aluminum in shear at elevated temperature

Creator:: Alhajeri, Saleh N.
Abstract:: Pure aluminum deformed in torsion (shear) at elevated temperatures reaches a broad "peak" stress and then undergoes about a 17% decrease in flow stress with deformation to roughly 1-2 equivalent uniaxial strain. Beyond this strain the flow stress is approximately constant. The sources for this softening are unclear. The suggested...
Resource Type:: Masters Thesis

Constrained thin film desorption through membrane separation

Creator:: Thorud, Johnathan D.
Abstract:: A constrained thin film desorption scheme has been experimentally tested to determine the desorption rates for water from an aqueous lithium bromide mixture through a confining membrane. Variable conditions include the inlet concentration, pressure differential across the membrane, and channel height. Desorption takes place in a channel created between two...
Resource Type:: Masters Thesis

Interactions of a fully modulated inclined jet with a crossflow

Creator:: Dano, Bertrand P. E.
Abstract:: Jets in crossflow are used in a wide range of engineering applications and have been studied for more than 60 years. The transversal penetration and structure of a jet placed in a crossflow is known to be strongly three-dimensional. It is believed that, by using a pulsed jet inclined in...
Resource Type:: Dissertation

An experimental study of flow boiling heat transfer enhancement in minichannels with porous mesh heating wall

Creator:: Wang, Hailei
Abstract:: A unique channel surface enhancement technique via diffusion-bonding a layer of conductive fine wire mesh onto the heating wall was developed and used to experimentally study flow boiling enhancement in parallel microchannels. Each channel was 1000 μm wide and 510 μm high. A dielectric working fluid, HFE 7000, was used...
Resource Type:: Dissertation

An experimental study of co-flow ammonia-water desorption in an oil-heated, microscale, fractal-like branching heat exchanger

Creator:: Mouchka, Gregory A.
Abstract:: An experimental study was performed in which an ammonia-water solution was desorbed within a branching fractal-like microchannel array. The solution entered in the center of a disk, and flowed out radially until discharging in to a gravity-driven separation chamber. Heat was added to the ammonia-water through a thin wall, above...
Resource Type:: Masters Thesis

A study of high shear multiphase flow in a microchannel

Creator:: Morse, Daniel R.
Abstract:: Microscale fluid processes are an increasingly important subgroup of fluid mechanics. Applications for heat transfer and micro-electro-mechanical devices use flows on the scale of less than one hundred microns. This study is part of a larger work in which a multiphase, high shear environment is studied in a microchannel that...
Resource Type:: Masters Thesis

The design of an aquatic insect imaging device as part of a system to automate insect classification for biomonitoring

Creator:: Sarpola, Matt J.
Abstract:: Population counts of aquatic insects are a valuable tool for monitoring the water quality of rivers and streams. However, the handling of samples in the lab for species identification is time consuming. An aquatic insect imaging device was designed as part of a system to automate aquatic insect classification and...
Resource Type:: Masters Thesis

Evaluating the effectiveness of interaction strategies between product developer and supply chain using activity based modeling in environmental benign product design

Creator:: Wang, Bo
Abstract:: With growing concerns on environment impact of industrial product development, the product developers are seeking better solutions to achieve desired environmental benign requirements by the regulators and customers besides economic growth. During the last decade, some of the most successful product development companies (such as HP) have established their own...
Resource Type:: Masters Thesis

Quantification of total and plastic 3D strain fields within micro-damaged polyurethane foam

Creator:: Sutton, Matthew T.
Abstract:: Local material damage that occurs within cellular solids, such as polymer foams and trabecular bone, and precedes local fractures of the cell struts or walls is called micro-damage. The accumulation of micro-damage within cellular solids is often undesirable, although it is thought to be vital to the development and health...
Resource Type:: Masters Thesis

Flow boiling of lithium bromide-water solution in microchannels, with application to desorption

Creator:: Fackrell, Kurt
Abstract:: Recent studies of flow boiling within microchannels have shown high heat fluxes, leading to successful design and testing of compact heat exchangers, cooling systems for electronics and other high efficiency, miniature components. An experimental study of flow boiling of a concentrated salt solution in microchannels is presented. Experiments examined flow...
Resource Type:: Masters Thesis

Development of a reduced-order dynamic model of a jet-in-crossflow from experimental data

Creator:: Pearen, Keith L.
Abstract:: A reduced-order dynamic model is derived that captures the primary dynamics of a jet-in-crossflow. This is significant progress toward the end goal of reduced order model based closed-loop flow control. The reduced order model is a set of differential equations obtained through the use of snapshot based Proper Orthogonal Decomposition...
Resource Type:: Masters Thesis

Micro-bubble dynamics in two-phase flow through a micro-channel

Creator:: Shepard, Thomas G.
Abstract:: An experimental investigation into the behavior of micro-bubbles flowing through a micro-channel has been conducted. Experiments were performed within a rectangular micro-channel with dimensions of 5 cm x 13.2 mm x l30 jim. Bubbles were generated in an electrolyte solution by electrolysis at the lower channel wall near the inlet....
Resource Type:: Masters Thesis

Modified linear theory and Kalman filtering for in flight projectile impact point prediction

Creator:: Hainz, Leonard C.
Abstract:: A method for real time in-flight prediction of the ground impact point of an indirect fire projectile is investigated. The method investigated is comprised of a combination of an impact point predictor and an extended Kalman filter state estimator based on modified linear theory. The modified linear theory model is...
Resource Type:: Masters Thesis

Evaluation and optimization of large-scale engineering system modularity using an axiomatic design approach

Creator:: Thielman, Jeffrey L.
Abstract:: Large-scale engineering systems provide important functions and at the same time address serious concerns to human society. Because of the complexity and resources involved, the development of these systems is currently a challenging undertaking. In this work, an axiomatic design approach, based on Suhs axiomatic design theory, and combined with...
Resource Type:: Masters Thesis

Model predictive control of a direct fire projectile equipped with canards

Creator:: Ollerenshaw, Douglas R.
Abstract:: Launch uncertainties in uncontrolled direct fire projectiles can lead to significant impact point dispersion, even at relatively short range. A model predictive control scheme for direct fire projectiles is investigated to reduce impact point dispersion. The control law depends on projectile linear theory to create an approximate linear model of...
Resource Type:: Masters Thesis

Application of infrared thermography for temperature measurement in microscale internal and external flows

Creator:: Patil, Vishal
Abstract:: Infrared (IR) thermography is applied to estimate heat transfer rates in external and internal microscale convective flows. The technique and analysis are developed in the context of external jet impingement flow and internal single-phase liquid flows. A heated-thin-foil thermography technique is applied to perform surface temperature visualization on a submerged...
Resource Type:: Masters Thesis

Void fraction variations in a fractal-like branching channel network

Creator:: Cullion, Rebecca
Abstract:: Two-phase flow in a fractal-like branching microchannel heat sink may have enhanced heat transfer capabilities over single phase flow in the same branching channel network. In order to exploit this potential, a complete understanding of flow boiling in this geometry is required. The fractal-like geometry is similar to that of...
Resource Type:: Dissertation

Simulating changing diameter distributions in a softwood sawmill

Creator:: Salichon, Maxence C.
Abstract:: Sawmills are very complex systems that involve many manufacturing processes. The variability of their raw material adds further to this complexity as each log has characteristics that determine its processing path. Therefore, computer simulation is a very useful technique for analyzing sawmill performance. This thesis describes a simulation computer model...
Resource Type:: Masters Thesis

Using discrete-event simulation to study the influence of log yard sorting on sawmill processing efficiency of small-diameter timber

Creator:: Pinon, Olivia J.
Abstract:: A sawmill is similar to other manufacturing enterprises when it comes to making decisions, scheduling production and meeting customer demands. In order to help sawmills achieve their goals, and because there is such a high degree of variability in the raw material used in this industry, computer simulation has proven...
Resource Type:: Masters Thesis

Properties of veneer sliced from serpentine-end-matched flitches

Creator:: Liu, Yuqing
Abstract:: Eighteen Ponderosa Pine (Pinus ponderosa Dougl.ex.laws) veneer flitches were randomly selected and crosscut into paired flitches. Serpentine-end-matched (SEM) joints were machined in the flitches, joint amplitude equal to the width in one half of the paired flitch and joint amplitude equal to 2/3 width in the other half of the...
Resource Type:: Masters Thesis

Dynamic modeling, control aspects and model predictive control of a parafoil and payload system

Creator:: Slegers, Nathan J.
Abstract:: Control issues are investigated for a parafoil and payload system with left and right parafoil brakes used as the control mechanism. It is shown through dynamic modeling and simulation that parafoil and payload systems can exhibit two basic modes of lateral control, namely, roll and skid steering. Using a small...
Resource Type:: Dissertation

Analyzing manufacturing system changes using discrete event simulation

Creator:: Baker, Eric S.
Abstract:: This research studied the effects of changing from a traditional manufacturing system to a cell manufacturing system in a value-added wood products company. Discrete event simulation was used to describe the current system and the proposed new systems. Parts were separated into part families that shared similar processing requirements. From...
Resource Type:: Masters Thesis

An American College Experience: It Tastes Like Burning

Creator:: Shapiro, David L.
Abstract:: A collection of short stories in the style of flash fiction. The themes of the stories include relationships, legality, and friendship. The stories are connect by themes, cross self-referencing, repetition, fragmentation, and characters. The main unifying feature is the characterization of the narrator through his response and commentary. The styles...
Resource Type:: Honors College Thesis

A hierarchical neuro-evolutionary approach to small quadrotor control

Creator:: Shepherd, Jack F., III
Abstract:: Quadrotors are unique among Micro Aerial Vehicles in providing excellent maneuverability (as opposed to winged flight),while maintaing a simple mechanical construction (as opposed to helicopters). This mechanical simplicity comes at a cost of increased controller complexity. Quadrotors are inherently unstable, in the sense that they are essentially unflyable by a...
Resource Type:: Masters Thesis

Numerical simulation of cavitating bubble-laden turbulent flows

Creator:: Shams Sobhani, Ehsan
Abstract:: Many engineering devices and propulsion systems suffer from undesirable effects of cavitation; such as degradation in the efficiency of pumps and turbines, generation of noise and vibration on ship propeller, increased drag and erosion of propeller blade, etc. In spite of decades of research on this problem, detailed study of...
Resource Type:: Dissertation

Reduced order modeling of legged locomotion in the horizontal plane

Creator:: Wickramasuriya, Gamika Arun
Abstract:: Sprawled-posture insects exhibit a remarkable ability to rapidly run in a stable manner over complex terrain, a feat that has yet to be equaled by man-made legged robots. Recent experimental results suggest that these insects may employ a hierarchical control structure, in which locomotion performance emerges from a combination of...
Resource Type:: Dissertation

Design, modeling, and performance of miniature reciprocating thermocompressor

Creator:: Edwards, Michael J.
Abstract:: Research in the miniaturization of thermomechanical systems in recent years has proven to be both rewarding and challenging. Micro-scale devices have tremendous technological potential but come with a new set of design problems. One such problem is energy storage. Heat actuated systems, driven primarily by thermal energy, take advantage of...
Resource Type:: Masters Thesis

Learning based methods applied to the MAV control problem

Creator:: Salichon, Max
Abstract:: This thesis addresses Micro Aerial Vehicle (MAV) control by leveraging learning based techniques to improve robustness of the control system. Applying classical control methods to MAVs is a difficult process due to the complexity of the control laws with fast and highly non-linear dynamics. These methods are mostly based on...
Resource Type:: Dissertation

Navigation and coordination of autonomous mobile robots with limited resources

Creator:: Knudson, Matthew D.
Abstract:: The use of autonomous robots in complex exploration tasks is rapidly increasing. Indeed, robots can provide speed and cost effectiveness in many tasks, as well as allow operation in environments that are hostile to humans. In this dissertation we: 1) provide two adaptive navigation algorithms; 2) develop a coordination mechanism;...
Resource Type:: Dissertation

Clearing bubble blockages in micro channels using a model predictive controller

Creator:: Patton, Chris
Abstract:: Micro scale systems are being utilized in a wide variety of chemical, biological and heat exchanger applications, but suffer from the development of vapor bubbles inside the microchannels due to convective boiling, leading to decreases in system performance. In this work, a simulation-based control strategy is employed to eliminate flow...
Resource Type:: Masters Thesis

Detecting fluid flows with bioinspired hair sensors

Creator:: Dickinson, Benjamin T.
Abstract:: Many animals detect prey or enhance their locomotion with information from hair-like receptors that are activated by local fluid flows. The utility of biological hair receptors has motivated the design of artificial hair sensors (AHS) for flow control applications where aerodynamic or hydrodynamic forces play a significant role in the...
Resource Type:: Dissertation

Adaptive methods for robust commercial vehicle control

Creator:: Junell, Jaime L.
Abstract:: This thesis explores the implementation of learning based control with predictive cruise control and the potential this technology has for increasing fuel efficiency while keeping on a well maintained schedule for commercial trucks. Traditional cruise control is wasteful when maintaining a constant velocity over rolling hills. Predictive cruise control is...
Resource Type:: Masters Thesis

Dynamics and stability of lateral plane locomotion on variable inclines

Creator:: Bonnono, Scott A.
Abstract:: An actuated, bipedal model is developed to investigate lateral plane locomotion dynamics and stability on inclines. Both the point mass case and rigid body case are considered. Variations in the force-free leg length are determined via inverse dynamics to explicitly and implicitly match prescribed lateral and fore-aft force profiles, respectively....
Resource Type:: Masters Thesis

Selecting a Marathon Training Program

Creator:: Weismann-Yee, Ryan
Abstract:: The marathon is well noted for the extreme stress it applies to the body and mind. The physiological aspects of marathon training were investigated and examined for someone unfamiliar with the field. Several training programs were investigated within a framework provided by the popular Daniels' Running Formula. By the Formula's...
Resource Type:: Honors College Thesis

Light Pollution and the Limiting Visual Magnitude in Corvallis, Oregon

Creator:: Grellmann, Carsten Christof
Abstract:: This study sought to ascertain the degree to which the night sky of Corvallis is affected by light pollution by determining the limiting visual magnitude. Defined as the brightness of the dimmest star that can be seen with the averted naked eye, the limiting visual magnitude establishes a quantitative standard...
Resource Type:: Honors College Thesis

Phase Separation in Microscale Convective Boiling

Creator:: Lewis, Kevin Terrence
Abstract:: It is hypothesized that extracting the vapor from two-phase flow in a microchannel will result in a lowered pressure drop required to drive the flow. The goal of this thesis is to construct an experimental device that will test this hypothesis by comparing a number of phase separating test conditions...
Resource Type:: Honors College Thesis

Design of a mechanically assisted dependent transfer mechanism for use on board commercial aircraft

Creator:: Gibson, Brenton D.
Abstract:: Business and recreation in the modern day world often include air travel as their cornerstone. Travelers who are disabled and wheelchair bound have to undergo a transfer process to board and deplane a commercial aircraft. This transfer process is typically done manually, with agents physically lifting the passenger who is...
Resource Type:: Masters Thesis

A multiscale modeling approach for bubble-vortex interactions in hydro-propulsion systems

Creator:: Finn, Justin Richard
Abstract:: Multiphase flow dynamics are important in many naval and turbomachinery applications, where bubble interaction with low pressure, vortical structures can lead to undesirable cavitation effects. To better understand the underlying phenomena, a multiscale numerical framework is developed to simulate bubble laden flow in dynamic hydro propulsion systems. Several subproblems in...
Resource Type:: Masters Thesis

Learning from action not taken in multiagent systems

Creator:: Khani, Newsha
Abstract:: Coordination in large multiagent systems in order to achieve a system level goal is a critical challenge. Given the agents' intention to cooperate, there is no guarantee that the agent actions will lead to good system objective especially when the system becomes large. One of the primary difficulties in such...
Resource Type:: Masters Thesis

Hydrodynamics of droplet impingement on heated surfaces : effects of nanofluid and nano-structured surface

Creator:: Shen, Jian
Abstract:: This study investigates the hydrodynamic characteristics of droplet impinging on heated surfaces using High Speed High Resolution (HSHR) imaging and evaluates the effect of surface temperature and using water and a nanofluid on a polished and a nano-structured surface. Three types of surfaces are used in the study: polished silicon,...
Resource Type:: Dissertation

Failure state identification for requirements development during complex system design

Creator:: Mueller, Jonathan D.
Abstract:: The increasing level of complexity in systems creates a growing challenge for engineers to design safe and reliable systems. The growing complexity can lead to possible moments when situations occur that were unanticipated or were not known that they could occur by designers and leave the system in an undesirable...
Resource Type:: Masters Thesis

Modeling convective boiling flow with in-situ local vapor extraction

Creator:: Salakij, Saran
Abstract:: The pressure drop of convective boiling flow may be reduced by extracting vapor locally since the entire generated vapor does not have to travel through the entire channel length. In this study, the theoretical model was developed to simulate a convective boiling flow through a fractal-like branching microchannel network with...
Resource Type:: Masters Thesis

Study of a constrained-film bubble absorber under cycle operating conditions

Creator:: Cardenas, Ruander
Abstract:: An experimental and numerical study of absorption of ammonia vapor bubbles into a constrained thin film of ammonia-water solution is presented in the context of a potential reduction in size of a heat-actuated heat pump component. A large-aspect-ratio channel with a depth of 600 µm restricts the thickness of the...
Resource Type:: Masters Thesis

Towards reliable and survivable ocean wave energy converters

Creator:: Brown, Adam C.
Abstract:: Ocean wave energy is a new and developing field of renewable energy with great potential. The energy contained in one meter of an average wave off the coast of Newport Oregon could supply dozens of homes with electricity. However, ocean waves are usually quite irregular which leads to large bursts...
Resource Type:: Masters Thesis

Design analysis using function-based failure propagation in failed system states

Creator:: Jensen, David Charles
Abstract:: For safety critical complex systems, reliability and risk analysis are important design steps. Implementing these analyzes early in the design stage can reduce costs associated with redesign and provide important information on design viability. In the past several years, various research methods have been presented in the design community to...
Resource Type:: Masters Thesis

Extension of early stage failure analysis tools to Prognostics Health Management design

Creator:: Kramer, Scott
Abstract:: Modern complex mechanical systems have evolved to a point of incredible complexity. Many now operate with significant assistance from automated response functions, and some operate without human operators at all. These increasingly complex systems have also become more expensive and more ambitions in mission, bringing about higher risk to both...
Resource Type:: Masters Thesis

Modeling and control of a biologically inspired compliant structure

Creator:: Ray, Cody W.
Abstract:: We hypothesize that the extraordinary maneuverability and efficiency of bats in flight are in part due to the compliant nature of their wing structures. We utilize the parameters of bat bones measured by biologists to create a biologically inspired model of a flapping system consisting of a rotating hub actuator...
Resource Type:: Masters Thesis

Risk-based design for multidisciplinary complex systems

Creator:: Farhangmehr, Farzaneh
Abstract:: The ultimate goal of large-scale design organizations are mainly to reduce costs and improve reliability and performance of systems while assessing how much risk (cost, schedule, scope) they can take and still remain competitive. To achieve this goal they need to develop tools to reach the most preferred design product...
Resource Type:: Masters Thesis

Mechanical linkage design for haptic rehabilitation and development of fine motor skills

Creator:: Streng, B. Taylor
Abstract:: Thousands of children and adults suffer from fine motor skill deficits due to developmental disabilities or brain trauma. In order to acquire or reclaim these precision motor movements, occupational therapists work closely with each patient to develop the muscle memory required for completing tasks such as handwriting or drawing. Although...
Resource Type:: Masters Thesis

Spatio – temporal temperature variations during droplet impingement evaporation : effects of nanofluid and nano-structured surface

Creator:: Graber, Christof
Abstract:: Droplet and spray impingement cooling are typically used in high heat flux thermal management. In this thesis, droplet impingement and evaporation heat transfer characteristics are determined from measured spatially- and temporally- varying fluid and surface temperatures. Unique to this study is the documentation of the effects of using a nanofluid...
Resource Type:: Masters Thesis

Numerical study of flow maldistribution in microchannels using fully resolved simulation

Creator:: Martin, Mathieu Georges Charles
Abstract:: This thesis addresses numerical simulation of flow maldistribution in microchannels. Microchannels are often associated with two phase-flows which can generate many problems such as plugging the channel or perturbing the flow. In this study we have used CFD and fully resolved technique to simulate what would happen in the case...
Resource Type:: Masters Thesis

Failure analysis of pre-notched composite laminated plates under four-point bending conditions

Creator:: Arias Gonzales, Sergio
Abstract:: Ever since composite laminate technology was introduced into the aerospace and automotive industry, there has been a need to fully understand the damage progression experienced by composite laminated plates in the presence of a notch. While numerous research studies have been conducted on this matter when subjected to in-plane loads,...
Resource Type:: Dissertation

Mechanical engineering design across cultures : a method of designing for cultures

Creator:: Van Bossuyt, Douglas L.
Abstract:: Mechanical design is often based on formal methodologies such as Quality Function Deployment. Techniques to quantitatively account for attractability, sensory perception, and affective design have been successfully incorporated into these methods and are receiving growing acceptance across many industries. Although the adoption of these methods marks a large improvement for...
Resource Type:: Masters Thesis

Experiments on a low aspect ratio wing at low Reynolds numbers

Creator:: Morse, Daniel R.
Abstract:: At the start of the 21st century much of the focus of aircraft design has been turned to unmanned aerial vehicles (UAVs) which generally operate at much lower speeds in higher risk areas than manned aircraft. One subset of UAVs are Micro Air Vehicles (MAVs) which usually are no larger...
Resource Type:: Dissertation

Risk-based negotiation for collaborative system design in a distributed environment

Creator:: Qiu, Yuming
Abstract:: Risk is a crucial decision factor besides traditional cost and performance during collaborative decision making in a distributed environment. Three main challenges exist: 1) stakeholders' different perspectives and/or diverse cultures can lead to inconsistent risk probability evaluations; 2) risk consequence is hard to be quantified in concrete unit; 3) risk...
Resource Type:: Dissertation

A study of adiabatic and diabatic flow boiling in parallel microchannels and fractal-like branching microchannels

Creator:: Daniels, Brian J.
Abstract:: A one-dimensional numerical model has been developed to study diabatic and adiabatic flow boiling in microchannels. This model accounts for developing flow effects and variable property effects. The model uses correlations for void fraction and two-phase multipliers found in the literature. The model has been used to study the performance...
Resource Type:: Dissertation

Particle image velocimetry studies of low Reynolds number flow in branching flow networks

Creator:: Kwak, Younghoon
Abstract:: A particle image velocimetry system was established to determine flow fields in low Reynolds number flows through a branching flow network. Due to the fabrication procedure of the test device, flows were limited to a Reynolds number of 1.5 in the largest channel. Data was acquired at each channel inlet,...
Resource Type:: Masters Thesis

Applications of the thermal wave technique in liquid thermal conductivity measurements and flow field diagnostics

Creator:: Wang, Zhefu
Abstract:: The thermal wave technique has been explored for the use of liquid thermal conductivity measurement and flow property diagnostics in this dissertation. For liquid thermal conductivity measurements, an experimental technique based on the thermal wave approach is developed. A stainless steel strip functions as both a heating element and a...
Resource Type:: Dissertation

Micro adiabatic combustion engine : concept development, simulation and combustion experiments

Creator:: Chewning, Scott R.
Abstract:: The current proliferation of portable electronic devices for personal communication, business and entertainment has created a demand for high energy density power supplies. A hydrocarbon fuel with a conversion efficiency of over 15% can provide greater energy density than current battery technology for these applications. Current micro-scale heat engines do...
Resource Type:: Masters Thesis

Experimental study of two-phase gas-liquid flow in a microscale fractal-like branching flow network

Creator:: Kwak, Younghoon
Abstract:: Two-phase gas-liquid flows in microscale fractal-like branching channel flow networks were experimentally studied to assess the validity of existing void fraction correlations and flow regimes based on superficial gas and liquid velocities. Void fractions were assessed using two different methods. First, void fraction data were acquired using a High-Speed-High-Resolution (HSHR)...
Resource Type:: Dissertation

Characterization of flow boiling in a fractal–like branching microchannel network

Creator:: Edward, Lee M.
Abstract:: Based on experimental investigations the present study evaluates flow instability and void fraction in a fractal-like branching microchannel network with rectangular cross-section. The hydraulic diameter of the channels ranged from 308μm at the inlet to 143μm at the outlet. The flow network used is characterized by set branching ratios for...
Resource Type:: Masters Thesis

Thermally actuated pumping of a single-phase fluid using surface asymmetry

Creator:: Jo, Myeong Chan
Abstract:: An experimental study of thermally actuated pumping of a single-phase, single-component fluid is presented in the context of thermal management of a heat source. The prominent feature of this pumping method is that the very heat that is to be removed from the heat source causes a net fluid motion....
Resource Type:: Masters Thesis

Identifying customer requirements and designing for modularity in developing specialized, low production volume products

Creator:: van Tamelen, Peter G.
Abstract:: Field biologists are in need of more specialized and technical equipment than they are able to produce on their own in order to collect data more efficiently or gather data that is not currently available. This presents a challenge for design engineers because these products are typically highly specialized and...
Resource Type:: Masters Thesis

The fracture toughness of medium density fiberboard and other fiber bridging composites

Creator:: Matsumoto, Noah T.
Abstract:: In many composites, fiber bridging develops as part of the fracture process. Fiber bridging invalidates many toughness evaluation methods such as the ASTM E399 and complicates the identification of crack length, which is a necessary parameter in energy methods. In order to measure the toughness of fiber bridging composites, an...
Resource Type:: Masters Thesis

Design of an automated system for imaging and sorting soil mesofauna

Creator:: Chamblin, Mike A.
Abstract:: Identification and population counts of soil mesofauna can be an important tool for soil ecologists to determine the soil biodiversity. Information provided from population counts can give insight to soil ecologists about the effects of human land use, monitoring soil and water health, benefits of soil biodiversity in agriculture, and...
Resource Type:: Masters Thesis

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