Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 2018

Full-Text Articles in Entire DC Network

The Impact Of Patient-Specific Vascular Structure On Localized Cooling In The Human Heart, Nathan Paul Spangenberg Sep 2019

The Impact Of Patient-Specific Vascular Structure On Localized Cooling In The Human Heart, Nathan Paul Spangenberg

Theses and Dissertations

Acute Myocardial Infarction (AMI) is the leading cause of worldwide death and disability, and approximately 720,000 Americans will experience an AMI in 2018. Studies have shown that rapid hypothermia therapy (<35°C) before reperfusion in patients with AMI can reduce infarct size by 37%. Localized therapeutic hypothermia has proven the potential to cool heart tissue rapidly following AMI, 3°C in 5 minutes. Using Materialise Mimics digital imaging software and the finite volume method we analyzed temperature distributions in six patient-specific left main coronary artery (LMCA) models. A mock circulatory loop was used to determine the exiting temperatures of a standard 7 Fr catheter to feed into our model with flow rates ranging from 29.2 ml/min to 68.85 ml/min. Our work showed that therapeutic hypothermia (TH) temperatures were evident at the outlets of three out of all six heart models, which varied in each left anterior descending (LAD) and left circumflex (LCX) artery depending on flowrate. Results of this study indicate that biovariability in patient-specific vascular structures significantly impacts therapeutic hypothermia (TH) treatment methods. These results indicate that further research is needed to examine more accurate physiological effects, such as pulsatile flow and vessel wall thickness. Future models will be used to provide insight to guide more efficient TH device designs and operation parameters to optimize patient outcomes following AMI.


Initial Development Of A Prototype Sensor Testbed For Fetal Monitoring, Christian Beauvais Aug 2019

Initial Development Of A Prototype Sensor Testbed For Fetal Monitoring, Christian Beauvais

Theses and Dissertations

The objective of this research is to design and manufacture a device that exhibits some of the bio-physiological signals relevant to fetal health monitoring. Currently, limited options exist for testing the performance of monitoring devices such as the tocodynamometer (TOCO) and electrocardiograph (ECG) that measure the bio-physiological signals of a woman and her fetus. Sensor designers need ways of generating and acquiring signals that do not carry the ethical burden of human testing. The development of such a device, as considered in this work, may involve using muscle wire or an inflatable tube as prospective foundations for simulating uterine contraction ...


Response Transmissibility For Load Identification Improved By Optimal Sensor Locations, Hanaa M. Alqam Aug 2019

Response Transmissibility For Load Identification Improved By Optimal Sensor Locations, Hanaa M. Alqam

Theses and Dissertations

A knowledge of loads acting on a structure is important for analysis and design. There are many applications in which it is difficult to measure directly the dynamic loads acting on a component. In such situations, it may be possible to estimate the imposed loads through a measurement of the system output response. Load identification through output response measurement is an inverse problem that is not only ill-conditioned, but in general leads to multiple solutions. Therefore, additional information, such as number and locations of the imposed loads must be provided ahead of time in order to allow for a unique ...


Functional Porous Polydimethlysiloxane As Piezoresistive And Piezoelectric Materials, Taissa Rose Michel Jul 2019

Functional Porous Polydimethlysiloxane As Piezoresistive And Piezoelectric Materials, Taissa Rose Michel

Theses and Dissertations

In this paper, polydimethylsiloxane (PDMS), carbon nanotubes (CNTs), and zinc oxide (ZnO) were combined to create functionalized piezoresistive and piezoelectric sensors for pressure sensing and energy harvesting. Samples were foamed to show that the increased deformability of the foam sensors makes them suitable for a range of applications including dexterous robotics, tactile sensing, energy harvesting, and biosensing. Uniform dispersion of CNTs was achieved with chloroform as the solvent. Samples were foamed using chemical blowing and scaffolding but granulated sugar at 70% porosity resulted in foamed samples with the most consistent mechanical properties. Samples underwent tensile and compressive testing for their ...


Impact Of Cycloalkanes On Ignition Propensity Measured As Derived Cetane Number In Multi-Component Surrogate Mixtures, Dalton Odell Carpenter Jul 2019

Impact Of Cycloalkanes On Ignition Propensity Measured As Derived Cetane Number In Multi-Component Surrogate Mixtures, Dalton Odell Carpenter

Theses and Dissertations

Cycloalkanes are one type of hydrocarbons present in real jet fuels. The distinct cyclic structure of the cyclo-alkanes impacts the chemical kinetic behavior differently compared to n- and iso-alkanes. At high temperatures, thermal decomposition reactions dominate, producing n-alkyl radicals similar to the oxidation reactions of n-alkanes thus promoting the reactivity. Whereas in low temperatures, the presence of the ring structure essentially suppresses the formation of alkylhydroperoxy radicals (QOOH) from alkylperoxy radicals (RO2), thus exhibiting similar reactivity to iso-alkanes. In previous generations of surrogate fuels, the cyclo-alkane functional group were largely ignored due to low levels of cycloalkanes in traditional jet ...


Surrogate Formulation Based On Chemical Functional Group Analysis, Stuart Nates Jul 2019

Surrogate Formulation Based On Chemical Functional Group Analysis, Stuart Nates

Theses and Dissertations

Chemical kinetic characteristics of real fuels exhibit high-dimensional complexity due to the excessive number of molecules and molecular classes. As a method of projecting this high-dimensional complexity, which is pertinent to real fuels, to the low-dimensional description, either a surrogate approach or detailed experiments have been utilized, can guide the construction of chemical kinetic models for real fuel. Although the validity of the surrogate approach has been extensively demonstrated by a wide range of canonical experiments for whole fuel/air mixtures, the use of empirical fuel property indicators still worries whether or not the surrogate mixture truly captures the more ...


A Model For Condensation Heat Transfer In Hydrophobic-­Hydrophilic Surfaces, Abdulwahab E. Alhashem Jul 2019

A Model For Condensation Heat Transfer In Hydrophobic-­Hydrophilic Surfaces, Abdulwahab E. Alhashem

Theses and Dissertations

The primary focus of this research is to provide a validated model for a comprehensive understanding of hydrophobic-­‐hydrophilic condensation on patterned-­‐ hybrid surface. Establishing the model requires the modeling of fully dropwise condensation (DWC) before applying modifications to evaluate heat transfer performance of patterned-­‐hybrid condensation surface.

The model for fully DWC consists of defining expressions for heat transfer through a single drop, maximum radius of the drop and drop-­‐size distribution which all are primarily based on the work in the literature. In this work the author utilized a proposed modified version of the simulation for drop-­‐size ...


Enhancing Thermal-Hydraulic Performance Of Parallel And Counter Flow Mini-Channel Heat Sinks Utilizing Secondary Flow: A Numerical And Experimental Study, Amitav Tikadar Jul 2019

Enhancing Thermal-Hydraulic Performance Of Parallel And Counter Flow Mini-Channel Heat Sinks Utilizing Secondary Flow: A Numerical And Experimental Study, Amitav Tikadar

Theses and Dissertations

Continual growth of hydraulic and thermal boundary layers along stream wise direction in conventional straight fin mini-channel heat sink causes gradual deterioration of their thermal performance. To enhance thermal-hydraulic performance by breaking and redevelopment of the boundary layers, this research aims to introduce a novel inter-connected mini-channel sinks. Two inter-connectors were positioned transversely between two adjacent mini-channels, which segmented the flow domain into three zones. Secondary flow was generated through the inter-connectors utilizing the pressure difference of the adjacent channels resulting in hydraulic and thermal boundary layers disruption and hence enhanced thermal-hydraulic performance of the mini-channel heat sink was achieved ...


3d Topology Optimization Of Spatially Reinforced Composites, Luis G. Bahamonde Jácome Jul 2019

3d Topology Optimization Of Spatially Reinforced Composites, Luis G. Bahamonde Jácome

Theses and Dissertations

Topology optimization is a numerical design tool used to generate structural concepts that present optimal load paths for a given set of functional requirements. This functional generative design capability has been used to lightweight high performance structures with 1D, 2D and 3D stress states. On the other hand, fiber-reinforced composites are the perfect candidate material to use in high performance structures due to the tailorability of their stiffness and strength properties. Although numerical tools that simultaneously tailor the composite material properties while optimizing the structural topology exist, these tools are inherently limited to 1D and 2D stress states.

This work ...


Mechanical Characterization And Non-Destructive Evaluation Of SicF/SicM Composites For Nuclear Applications, Donald J. Mccleeary Jul 2019

Mechanical Characterization And Non-Destructive Evaluation Of SicF/SicM Composites For Nuclear Applications, Donald J. Mccleeary

Theses and Dissertations

The SiCf/SiCm composite material is a promising candidate for accident tolerant fuel cladding in light water reactors and for structural elements in high temperature reactors. The material demonstrates exceptional toughness when compared to monolithic ceramics. It is critical to characterize the mechanical behavior, internal damage and ultimate strength of these composites under relevant loading conditions. In this thesis, the author developed and improved several mechanical characterization and non-destructive evaluation methods and applied them to SiCf/SiCm composites. Impulse excitation (IE) analysis of damaged SiCf/SiCm composite disks following controlled impact testing shows a ...


Motor Control Systems Analysis, Design, And Optimization Strategies For A Lightweight Excavation Robot, Austin Jerold Crawford May 2019

Motor Control Systems Analysis, Design, And Optimization Strategies For A Lightweight Excavation Robot, Austin Jerold Crawford

Theses and Dissertations

This thesis entails motor control system analysis, design, and optimization for the University of Arkansas NASA Robotic Mining Competition robot. The open-loop system is to be modeled and simulated in order to achieve a desired rapid, yet smooth response to a change in input. The initial goal of this work is to find a repeatable, generalized step-by-step process that can be used to tune the gains of a PID controller for multiple different operating points. Then, sensors are to be modeled onto the robot within a feedback loop to develop an error signal and to make the control system self-corrective ...


Predicting The Mechanical Properties Of Nanocomposites Reinforced With 1-D, 2-D And 3-D Nanomaterials, Scott Edward Muller May 2019

Predicting The Mechanical Properties Of Nanocomposites Reinforced With 1-D, 2-D And 3-D Nanomaterials, Scott Edward Muller

Theses and Dissertations

Materials with features at the nanoscale can provide unique mechanical properties and increased functionality when included as part of a nanocomposite. This dissertation utilizes computational methods at multiple scales, including molecular dynamics (MD) and density functional theory (DFT), and the coupled atomistic and discrete dislocation multiscale method (CADD), to predict the mechanical properties of nanocomposites possessing nanomaterials that are either 1-D (carbyne chains), 2-D (graphene sheets), or 3-D (Al/amorphous-Si core-shell nanorod).

The MD method is used to model Ni-graphene nanocomposites. The strength of a Ni-graphene nanocomposite is found to improve by increasing the gap between the graphene sheet and ...


Modeling Of Complex Parts For Industrial Waterjet Cleaning, Braden James May 2019

Modeling Of Complex Parts For Industrial Waterjet Cleaning, Braden James

Theses and Dissertations

Industrial high-pressure waterjet cleaning is common to many industries. The modeling in this paper functions inside a collaborative robotic framework for high mix, low volume processes where human robot collaboration is beneficial. Automation of pressure washing is desirable for economic and ergonomic reasons. An automated cleaning system needs path simulation and analysis to give the operator insight into the predicted cleaning performance of the system. In this paper, ablation, the removal of a substrate coating by waterjet, is modeled for robotic cleaning operations. The model is designed to work with complex parts often found in spray cleaning operations, namely parts ...


Structural Health Monitoring Of Laminate Structures Using Shear-Mode Piezoelectric Sensors, Hussain Altammar May 2019

Structural Health Monitoring Of Laminate Structures Using Shear-Mode Piezoelectric Sensors, Hussain Altammar

Theses and Dissertations

Structural health monitoring (SHM) employing embedded piezoelectric transducers has shown potential as a promising solution for inspection of different engineering structures such as aircraft, bridges, and renewable energy structures. Despite advancements in the field of ultrasonic SHM, inspection of laminate structures is still a major challenge due to their susceptibility to various joint defects. This thesis presents a novel approach to tackle the challenge of inspecting laminate structures using shear-mode (d35) piezoelectric transducers that are made of lead zirconate titanate (PZT).

This study begins with the characterization of d35 piezoelectric transducers using analytical, numerical, and experimental approaches. The results were ...


Fault Adaptive Workload Allocation For Complex Manufacturing Systems, Charlie B. Destefano May 2019

Fault Adaptive Workload Allocation For Complex Manufacturing Systems, Charlie B. Destefano

Theses and Dissertations

This research proposes novel fault adaptive workload allocation (FAWA) strategies for the health management of complex manufacturing systems. The primary goal of these strategies is to minimize maintenance costs and maximize production by strategically controlling when and where failures occur through condition-based workload allocation.

For complex systems that are capable of performing tasks a variety of different ways, such as an industrial robot arm that can move between locations using different joint angle configurations and path trajectories, each option, i.e. mission plan, will result in different degradation rates and life-expectancies. Consequently, this can make it difficult to predict when ...


Flow Structures And Aerodynamic Loads Of A Rolling Wing In A Free Stream, Randall Berdon May 2019

Flow Structures And Aerodynamic Loads Of A Rolling Wing In A Free Stream, Randall Berdon

Theses and Dissertations

The leading-edge vortex (LEV) is a structure found in unsteady aerodynamics that can alter the forces induced on wings and other rotating structures. This thesis presents an experimental study on LEV development on low aspect-ratio wing rolling in a uniform flow at high angles of attack. The flow structure dynamics of rotating wings in the presence of a free stream are not well understood due to the limited studies under these conditions. In this study, a broad parameter space with varying advance ratio and wing radius of gyration are analyzed using dye-visualizations. In most cases, either a conical LEV structure ...


Leading-Edge Vortex Development On A Maneuvering Wing In A Uniform Flow, Kevin Wabick May 2019

Leading-Edge Vortex Development On A Maneuvering Wing In A Uniform Flow, Kevin Wabick

Theses and Dissertations

Vortices interacting with the solid surface of aerodynamic bodies are prevalent across a broad range of geometries and applications, such as dynamic stall on wind turbine and helicopter rotors, the separated flows over flapping wings of insects, birds, formation of the vortex wakes of bluff bodies, and the lift-producing vortices formed by aircraft leading-edge extensions and delta wings. This study provides fundamental insights into the formation and evolution of such vortices by considering the leading-edge vortices formed in variations of a canonical flapping wing problem.

Specifically, the vorticity transport for three distinct maneuvers are examined, a purely rolling wing, a ...


Urans V&V For Kcs Free Running Course Keeping And Maneuvering Simulations In Calm Water And Regular Head/Oblique Waves, Dong-Hwan Kim May 2019

Urans V&V For Kcs Free Running Course Keeping And Maneuvering Simulations In Calm Water And Regular Head/Oblique Waves, Dong-Hwan Kim

Theses and Dissertations

The capability of CFD is assessed by utilizing CFDShip-Iowa V4.5 for the prediction of the 6DOF motion responses, forces, moments and the local flow field of the 2.7m KCS model in various weather/operating conditions. The discretized propeller is preferred and the rudder is designed to be active up to ±35 degrees. Grid triplets are generated with the refinement ratio √2 and verification is achieved for the resistance and propeller open water tests while for the other tests is only partially fulfilled. The verification shows unsmooth convergence, however, the errors from grid triplets are small. The propeller open ...


Understanding The Strain Localization And Progressive Damage Growth At The Free-Edge Of Composite Laminates Using Digital Image Correlation, Addis Tessema Apr 2019

Understanding The Strain Localization And Progressive Damage Growth At The Free-Edge Of Composite Laminates Using Digital Image Correlation, Addis Tessema

Theses and Dissertations

Understanding the mechanics of Fiber Reinforced Composites (FRC) that guide the design and optimization of laminate structures, have attracted numerous researchers. For the last five decades, various analytical and numerical models have been developed to understand the damage and failure mechanisms in FRC. For long, Classical laminate plate theory (CLPT) has majorly been used as a theoretical guide in the design of composite structures. The CLPT framework is developed based on the consideration of an infinitesimal wide plate that depicts a planar stress condition. Thus, as it considers only the planar stresses, the out of plane interlaminar stresses are absent ...


Acoustoelastic Metamaterial With Simultaneous Noise Filtering And Energy Harvesting Capability From Ambient Vibrations, Fariha Mir Apr 2019

Acoustoelastic Metamaterial With Simultaneous Noise Filtering And Energy Harvesting Capability From Ambient Vibrations, Fariha Mir

Theses and Dissertations

Harvesting unused and untapped energy from ambient vibration noise and acoustic sound waves is an emerging field of research in the recent years. Utilization of the energy with a wide band of the frequency spectrum from the vibrational sources alone stands as one of the most promising ways to power small electronic devices, smartphones, local structural health monitoring (SHM) sensors and home and workshop appliances. Various sources of ambient vibration and acoustic noise can be found around us in our everyday life. These sources are abundant in almost all the engineering industries and manufacturing facilities for example in aerospace, mechanical ...


Structural Health Monitoring And Non-Destructive Inspection Of Composite And Metallic Structures, Asaad Qasim Migot Apr 2019

Structural Health Monitoring And Non-Destructive Inspection Of Composite And Metallic Structures, Asaad Qasim Migot

Theses and Dissertations

Structural Health Monitoring (SHM) and Nondestructive Testing (NDT) techniques are being used as effective tools for investigating variety of civil, mechanical, and aerospace applications. In recent years, these techniques become such incredible tools for continuously monitoring of various structures. The aim of the dissertation work is to develop SHM and NDT methodologies for acoustic emission sources localization, damage detection and quantification in metallic and composite structures using a network of sensors, guided wave and developed imaging methods. This work is implemented through preparing metallic and composite specimens, setting up experiments, designing efficient networks of sensors, modeling guided wave interaction with ...


Plasma Surface Functionalization Of Afp Manufactured Composites For Improved Adhesive Bond Performance, Ibrahim Sarikaya Apr 2019

Plasma Surface Functionalization Of Afp Manufactured Composites For Improved Adhesive Bond Performance, Ibrahim Sarikaya

Theses and Dissertations

High-performance composite structures not only require a reliable fabrication process when creating primary structures, but also a high fidelity and repeatable bonding process for the assembled components. During the assembly process, surface contaminants are a major concern as they have the potential to compromise the bond quality resulting in poor bond strength, low failure load, and undesirable failure modes of the adhesively bonded structures. This is further complicated by composite materials inherently possessing low surface energy and thus exhibiting low adhesive property. Therefore, detecting and removing contaminants on the pre-bond composite surface is an active research topic in pursuit of ...


Development Of Scalable And Tunable Super- Hydrophilic And - Hydrophobic Coatings On The Cu Substrate For Phase Change Heat Transfer Applications, Raikan Saad Dawas Apr 2019

Development Of Scalable And Tunable Super- Hydrophilic And - Hydrophobic Coatings On The Cu Substrate For Phase Change Heat Transfer Applications, Raikan Saad Dawas

Theses and Dissertations

The aim of this study is to enhance and sustain the thin liquid film evaporation (TLFE) as well as dropwise condensation (DWC) on scalable copper substrates. The current dissertation consists of two sections. The objective of the first section is to enhance the dry cooling technology which is widely used in industrial applications such as in the air side of power plants, AC unit, or electronic cooling. However, the thermal dissipation performance is limited with low heat transfer coefficients (HTCs) due to the low thermal conductivity and density of the air. Inspired by the phase change heat transfer during the ...


Surface Science And Engineering Of Nano-Structured Cathodes For Intermediate Temperature Solid Oxide Fuel Cells, Yeting Wen Apr 2019

Surface Science And Engineering Of Nano-Structured Cathodes For Intermediate Temperature Solid Oxide Fuel Cells, Yeting Wen

Theses and Dissertations

The bulk-to-surface Sr-segregation can seriously compromise the stability of oxygen electrocatalysis in Sr-doped perovskite oxides such as La1-xSrxCoO3-δ and La1-xSrxCo1- yFeyO3-δ and limit their practical applications as cathode materials in solid oxide fuel cells. Although such chemical instability has been actively studied in recent years, fundamental understanding of Sr-segregation process vs temperature and time, particularly under real-world conditions, as well as the suppression method, are still needed. This PhD dissertation aims to acquire fundamental knowledge of Sr-segregation process under practical conditions in solid oxide fuel cells and develop suppression method to ensure the long-term stability through surface modifications.

To gain ...


Friction Stir Additive Manufacturing(Fsam) Of 2050 Al-Cu-Li Alloy, Ilana Lu Apr 2019

Friction Stir Additive Manufacturing(Fsam) Of 2050 Al-Cu-Li Alloy, Ilana Lu

Theses and Dissertations

As a solid state process, friction stir welding (FSW) is an advantageous joining method for higher strength aluminum alloys such as 2050 Al-Cu-Li which are not readily fusion welded. This study explores the potential of friction stir lap welding (FSLW) as an additive manufacturing process for this aluminum-lithium alloy. To accomplish this, lap weld joints were performed so that each additional layer would penetrate the preceding weld pass which creates a large, stacked build. Excess material is machined away leaving only weld. Cast AA2050 is explored in this study as a more cost-efficient feedstock for this process as compared to ...


A Mems Dual Vertical Electrometer And Electric Field-Mill, George C. Underwood Mar 2019

A Mems Dual Vertical Electrometer And Electric Field-Mill, George C. Underwood

Theses and Dissertations

Presented is the first iteration of a Microelectromechanical System (MEMS) dual vertical electrometer and electric field-mill (EFM). The device uses a resonating structure as a variable capacitor that converts the presence of a charge or field into an electric signal. Previous MEMS electrometers are lateral electrometers with laterally spaced electrodes that resonate tangentially with respect to each other. Vertical electrometers, as the name suggests, have vertically spaced electrodes that resonate transversely with respect to each other. The non-tangential movement reduces damping in the system. Both types demonstrate comparable performance, but the vertical electrometer does so at a fraction of the ...


Micro-Contacts With 3-D Surfaces Made With Grayscale Lithography, Paul L.J. Michaud Mar 2019

Micro-Contacts With 3-D Surfaces Made With Grayscale Lithography, Paul L.J. Michaud

Theses and Dissertations

MEMS switches show advantages over FET transistors and PIN diodes for switching applications due to low contact resistance, high linearity, low power use, better isolation and lower insertion loss. The switches have not replaced FETs or PIN diodes due to perceived limitations in their reliability and the need for stable contact resistance. In order to create switches acceptable for industry applications, research on micro-contact physics and failure mechanisms of micro-contacts is necessary to develop durable contact surfaces. The aim of this research was to design and fabricate micro-contacts with three-dimensional surfaces using grayscale lithography. The goal was to create devices ...


Event-Based Visual-Inertial Odometry On A Fixed-Wing Unmanned Aerial Vehicle, Kaleb J. Nelson Mar 2019

Event-Based Visual-Inertial Odometry On A Fixed-Wing Unmanned Aerial Vehicle, Kaleb J. Nelson

Theses and Dissertations

Event-based cameras are a new type of visual sensor that operate under a unique paradigm. These cameras provide asynchronous data on the log-level changes in light intensity for individual pixels, independent of other pixels' measurements. Through the hardware-level approach to change detection, these cameras can achieve microsecond fidelity, millisecond latency, ultra-wide dynamic range, and all with very low power requirements. The advantages provided by event-based cameras make them excellent candidates for visual odometry (VO) for unmanned aerial vehicle (UAV) navigation. This document presents the research and implementation of an event-based visual inertial odometry (EVIO) pipeline, which estimates a vehicle's ...


Fracture Toughness And Fatigue Crack Growth Rate Characterization Of Inconel 718 Formed By Laser Powder Bed Fusion, Charles C. Hohnbaum Mar 2019

Fracture Toughness And Fatigue Crack Growth Rate Characterization Of Inconel 718 Formed By Laser Powder Bed Fusion, Charles C. Hohnbaum

Theses and Dissertations

Continuing improvement in the field of AM of metals provides the opportunity for direct fabrication of aerospace parts. AM was once used in large part for rapid prototyping but improvements in technology and increases in the knowledge base of AM materials has provided the opportunity for manufacture of AM parts for operational use. The ability to create low numbers of unique parts without having to invest in expensive tooling provides great economic incentive to utilize this technique. IN718 is the most common high temperature alloy used in the aerospace industry and lends itself readily to formation by LPBF. The superior ...


Flow Behavior In Radial Rotating Detonation Engines, Scott A. Boller Mar 2019

Flow Behavior In Radial Rotating Detonation Engines, Scott A. Boller

Theses and Dissertations

Recent progress has been made in demonstrating Radial Rotating Detonation Engine (RRDE) technology for use in a compact Auxiliary Power Unit with a rapid response time. Investigation of RRDEs also suggests an increase in stable operating range, which is hypothesized to be due to the additional degree of freedom in the radial direction which the detonation wave can propagate. This investigation seeks to determine if the detonation wave is in fact changing its radial location. High speed photography was used to capture chemiluminescence of the detonation wave within the channel to examine its radial location, which was found to vary ...