Micro--Piv Measurements And Numerical Simulations Of Induced Charge Electro-Osmosis Around A Conducting Metal Rod,
2013
Old Dominion University
Micro--Piv Measurements And Numerical Simulations Of Induced Charge Electro-Osmosis Around A Conducting Metal Rod, William George Rosen
Mechanical & Aerospace Engineering Theses & Dissertations
The induced charge electro-osmotic (ICEO) flow around a conducting metal rod positioned in the center of a microchannel was analyzed through physical experimentation and numerical simulation. The experimental set up consisted of a straight microchannel connecting two fluid reservoirs with a square wave AC electric field applied across the microchannel. The electric field for the experimental tests ranged from 100 V /cm to 200 V/cm at frequencies from 500 Hz to 1.5 kHz. The numerical simulations used a similar geometric setup but were exposed to both a direct current (DC) and alternating current (AC) applied electric field. The electric field …
Characterization Of A Spiral Microfluidic Focusing Device For Continuous Single Cell Impedance-Based Cytometry Applications,
2013
Old Dominion University
Characterization Of A Spiral Microfluidic Focusing Device For Continuous Single Cell Impedance-Based Cytometry Applications, Daniel Riley
Mechanical & Aerospace Engineering Theses & Dissertations
A major focus in the field of cell characterization is the quantification of cell dielectric properties in order to develop low-cost, portable microfluidic devices that can, among other things, perform point-of-care detection of rare diseases and complete blood counts. Impedance-based cytometry has become an advantageous tool to ascertain these properties, wherein it is important that cells pass through the same point in a channel cross-section one at a time to ensure accurate and repeatable readings. This study documents the assessment of an 8-loop 160 μm (W) x 80 μm (H) spiral microchannel used to focus 10 μm polystyrene particles. In …
Communications: Moving Data,
2013
Morehead State University
Communications: Moving Data, Robert J. Twiggs
Robert "Bob" Twiggs STEM Education Collection
A PowerPoint Presentation created by Professor Bob Twiggs on "Communications: Moving Data" from March 24, 2013.
Evaluation Of The Thorax Of Manduca Sexta For Flapping Wing Micro Air Vehicle Applications,
2013
Air Force Institute of Technology
Evaluation Of The Thorax Of Manduca Sexta For Flapping Wing Micro Air Vehicle Applications, Brian C. Cranston
Theses and Dissertations
The tobacco hornworm hawkmoth (Manduca sexta) provides an excellent model from which to gather knowledge pertaining to the development of a Flapping Wing Micro Air Vehicle (FWMAV). One of the major challenges in design of a FWMAV is the energy demanding nature of low Reynolds number flapping flight. Therefore, an understanding of the power required by the flight muscles to actuate the wings is essential for the design of a FWMAV. The M.sexta wing/thorax mechanism was evaluated as a mechanical system in order to gain insight to the mechanical power required to produce the full natural wing stroke. A unique …
Power Requirements For Bi-Harmonic Amplitude And Bias Modulation Control Of A Flapping Wing Micro Air Vehicle,
2013
Air Force Institute of Technology
Power Requirements For Bi-Harmonic Amplitude And Bias Modulation Control Of A Flapping Wing Micro Air Vehicle, Justin R. Carl
Theses and Dissertations
Flapping wing micro air vehicles (FWMAV) have been a growing field in the research of micro air vehicles, but little emphasis has been placed on control theory. Research is ongoing on how to power FWMAVs where mass is a major area of concern. However, there is little research on the power requirements for the controllers to manipulate the wings of a FWMAV. A novel control theory, BABM, allows two actuators to produce forces and moments in five of the FWMAV's six DOF. Several FWMAV prototypes were constructed and tested on a six-component balance. Data was collected for varying control parameters …
Effects Of Stereoscopic 3d Digital Radar Displays On Air Traffic Controller Performance,
2013
Air Force Institute of Technology
Effects Of Stereoscopic 3d Digital Radar Displays On Air Traffic Controller Performance, Jason G. Russi
Theses and Dissertations
Air traffic controllers are responsible for directing air traffic based upon decisions made from traffic activity depicted on 2Dimensional (2D) radar displays. Controllers must identify aircraft and detect potential conflicts while simultaneously developing and executing plans of action to ensure safe separation is maintained. With a nearly 100% increase in traffic expected within the next decade (FAA, 2012a), controllers' abilities to rapidly interpret spacing and maintain awareness for longer durations with increased workload will become increasingly imperative to safety. The current display design spatially depicts an aircraft's position relative to the controller's airspace as well as speed, altitude, and direction …
Aerial Networking For The Implementation Of Cooperative Control On Small Unmanned Aerial Systems,
2013
Air Force Institute of Technology
Aerial Networking For The Implementation Of Cooperative Control On Small Unmanned Aerial Systems, Scott A . Songer
Theses and Dissertations
The employment of Small Unmanned Aerial Systems (SUAS) for reconnaissance and surveillance missions is a vital capability of the United States military. Cooperative control algorithms for SUAS can enable tactical multi-vehicle configurations for communications extension, intelligent navigation, and a multitude of other applications. Past research at AFIT has designed and simulated a cooperative rover-relay algorithm for extended communications and has investigated its implementation through various modem configurations. This research explores aerial networking options for implementing cooperative control and applies them to an actual SUAS. Using Commercial Off-The-Shelf (COTS) hardware, a system was designed and flight tested to implement the rover-relay …
Feasibility Analysis On The Utilization Of The Iridium Satellite Communications Network For Resident Space Objects In Low Earth Orbit,
2013
Air Force Institute of Technology
Feasibility Analysis On The Utilization Of The Iridium Satellite Communications Network For Resident Space Objects In Low Earth Orbit, John R. Claybrook
Theses and Dissertations
In recent years, space has become more congested and contested, particularly in low Earth orbit (LEO), generating the need for a low-latency capability to provide precise orbital knowledge and accurate space situational awareness information. This thesis investigates the feasibility of resident space objects (RSOs) in LEO communicating continuously with ground operators or users through the Iridium Satellite Communications Network. Due to the problem's complexity and required time for computation, a test-industry technique called Design of Experiments is implemented in order to efficiently study the feasibility of the communication link. Specifically, an optimal response surface method is chosen to design the …
Computational Simulation Of Explosively Generated Pulsed Power Devices,
2013
Air Force Institute of Technology
Computational Simulation Of Explosively Generated Pulsed Power Devices, Mollie C. Drumm
Theses and Dissertations
Technology and size constraints have limited the development of the end game mechanisms of today's modern military weapons. A smaller, more efficient means of powering these devices is needed, and explosive pulsed power devices could be that answer. While most prior research has been in the experimental field, there is a need for more theory-based research and a computer modeling capability. The objective of this research was to use experimental data collected by the US Army at Redstone Arsenal from their ferroelectric generator (FEG) design in combination with the ALEGRA-EMMA code to develop a computer model that can accurately represent …
Error Characterization Of Vision-Aided Navigation Systems,
2013
Air Force Institute of Technology
Error Characterization Of Vision-Aided Navigation Systems, Daniel A . Marietta
Theses and Dissertations
The goal of this work is to characterize the errors committed by an Image Aided Navigation (IAN) algorithm that has been developed for use as a navigation tool in GPS denied areas. The filter under study was developed by the Air Force Institute of Technology's Advanced Navigation Technology center, and has been the focus of numerous research efforts. Unfortunately, these studies have all been based on single runs or simulations, and such results may not be indicative of the true filter performance. This problem extends to IAN publications in general; no analysis of IAN based upon a sizable real world …
Pseudolite Architecture And Performance Analysis For The Faa's Nextgen Airspace,
2013
Air Force Institute of Technology
Pseudolite Architecture And Performance Analysis For The Faa's Nextgen Airspace, Joseph A . Czabaranek
Theses and Dissertations
By 2025 the FAA plans to have fully implemented its NextGen Airspace design. NextGen takes advantage of modern positioning technologies as well as automation, data sharing, and display technologies that will allow more efficient use of our ever busier National Airspace (NAS). A key element of NextGen is the transition from surveillance RADAR providing aircraft separation and navigation to the use of the GPS and Automatic Dependent Surveillance Broadcast (ADS-B). ADS-B couples the precision of the GPS with networked ground and airborne receivers to provide precise situational awareness to pilots and controllers. The result is increased safety, capacity, and access …
Opto-Mechanical Design Of A Chromotomographic Imager Direct-Vision Prism Element,
2013
Air Force Institute of Technology
Opto-Mechanical Design Of A Chromotomographic Imager Direct-Vision Prism Element, Timothy E. Coon
Theses and Dissertations
Chromotomographic Imaging (CTI) offers advantages in remote sensing by resolving intensity distribution spatially, spectrally, and temporally. The Chromotomography Experiment (CTEx) at the Air Force Institute of Technology (AFIT) explores the application of CTI as a space-based observer. Previous work in instrument development has revealed many of the intricacies of component fabrication and how they impact the resolving of image data. The proposed CTEx instrument has as its chromatic dispersion element a direct-vision prism (DVP) that is made to rotate in order to achieve multiple projection angles. Analysis of previous research established the need for a more accurate characterization of the …
Using Hysteretic Energy To Evaluate Damping Characteristics Of Hard Coating On Titanium,
2013
Air Force Institute of Technology
Using Hysteretic Energy To Evaluate Damping Characteristics Of Hard Coating On Titanium, Colin C. Engebretsen
Theses and Dissertations
Current methods of material damping evaluation consist of bending tests involving half-power bandwidth base excitation or free decay methods measured by laser vibrometer. These methods are accompanied by complex, nonlinear strain evaluation; they are vulnerable to undesired air damping; and they require less than commonplace equipment. The measurement of hysteretic energy loss in axial cyclic loading alleviates these difficulties. By using common tensile testing machines, strain is kept linear and air damping is of no concern. Furthermore, the static test section allows for simplified environmental variation for high temperature or high humidity testing. This study set forth to advance and …
Effects Of Temperature On The Performance Of A Small Internal Combustion Engine At Altitude,
2013
Air Force Institute of Technology
Effects Of Temperature On The Performance Of A Small Internal Combustion Engine At Altitude, Travis D. Husaboe
Theses and Dissertations
The effects of atmospheric pressure and temperature variations on the performance of small internal combustion (IC) engines operating at altitudes significantly above sea level are not widely documented. Using an altitude chamber and fuel-injected twostroke engine, data were collected while varying air temperature along with pressure. The peak engine power was 4.1 kW at roughly sea level standard conditions and dropped to 3.5 kW at the standard conditions for an altitude of 1.5 km. At a combination of pressure and temperature corresponding to an altitude of 3 km, peak power fell further to 2.5 kW. The combined effects of standard …
Design Of A Control Moment Gyroscope Attitude Actuation System For The Attitude Control Subsystem Proving Ground,
2013
Air Force Institute of Technology
Design Of A Control Moment Gyroscope Attitude Actuation System For The Attitude Control Subsystem Proving Ground, Samuel C. Johnson
Theses and Dissertations
All spacecraft represent a considerable investment of both time and money. To ensure mission success, testing and validation of all vital systems is crucial to the design process. The attitude control subsystem (ACS) is typically tested thoroughly, to include both hardware and control algorithms. Computer simulations offer a simple and relatively cheap method of predicting the performance of the ACS; however, computer simulations cannot provide the assurances necessary to qualify an ACS hardware configuration or control algorithm spaceworthy. For this reason, physical spacecraft simulators must be used to validate ACS dynamics. Previous research showed there is room for significant improvement …
Characterization Of Rotating Detonation Engine Exhaust Through Nozzle Guide Vanes,
2013
Air Force Institute of Technology
Characterization Of Rotating Detonation Engine Exhaust Through Nozzle Guide Vanes, Nick D. Debarmore
Theses and Dissertations
A RDE has higher thermal efficiencies in comparison to its traditional gas turbine counterparts. Thus, as budgets decrease and fuel costs increase, RDEs have become a research focus for the United States Air Force. An integration assembly for attaching the first NGV section from a T63 gas turbine engine to a 6 inch diameter RDE was designed and built for this study. Pressure, temperature, and unsteadiness measurements were completed in this study to characterize the exhaust flow of the RDE through the NGVs. The experiment found that stagnation pressure dropped an average of 4% through the NGVs, and that unsteadiness …
Creep Of Hi-Nicalon S Fiber Tows At Elevated Temperature In Air And In Steam,
2013
Air Force Institute of Technology
Creep Of Hi-Nicalon S Fiber Tows At Elevated Temperature In Air And In Steam, Theodore R. Shillig
Theses and Dissertations
Structural aerospace components require materials that have superior long-term mechanical properties and can withstand severe environmental conditions, such as high temperatures, high pressures and moisture. Ceramic-matrix composites (CMCs) are capable of maintaining excellent strength and creep resistance at high temperatures, which makes them attractive candidate materials for aerospace applications, particularly in propulsion components. Silicon Carbide (SiC) ceramic fibers have been used as constituent materials in CMCs, although oxidation of the SiC to SiO2 has been a known fiber degradation mechanism. Recently developed near stoichiometric Hi-Nicalon-S fibers have shown significant improvements in thermo-chemical stability. Creep of the Hi-Nicalon-S fibers at elevated …
Integration Of An Inter Turbine Burner To A Jet Turbine Engine,
2013
Air Force Institute of Technology
Integration Of An Inter Turbine Burner To A Jet Turbine Engine, Matthew M. Conrad
Theses and Dissertations
As aircraft power requirements continue to grow, whether for electrical systems or increased thrust, improved engine efficiency must be found. An Ultra-Compact Combustor (UCC) is a proposed apparatus for accomplishing this task by burning in the circumferential direction as a main combustor or an Inter-Turbine Burner (ITB). In order for the UCC to be viable it is important to study the effects of feeding the core and circumferential flows from a common gas reservoir. This research effort has developed a diffuser, for the AFIT Combustion Laboratory, that is capable of 80/20, 70/30, and 60/40 mass flow splits between the core …
Application Of Finite Element To Evaluate Material With Small Modulus Of Elasticity,
2013
Air Force Institute of Technology
Application Of Finite Element To Evaluate Material With Small Modulus Of Elasticity, Boyce H. Dauby
Theses and Dissertations
This thesis describes the development of a series of models utilizing the commercial finite element suite ABAQUS specifically to apply towards the study of biological tissue. The end goal is to be able to obtain the material properties of the Manducca Sexta, a biological inspiration for flapping wing micro-air vehicles. Two finite element models were used to analyze the results of two prior studies of other researchers. A flat punch elastic model examined boundary effects and confirmed that the point of indentation was far enough removed from the boundary. The hyperelastic spherical indentation experiment examined the effects of coefficient of …
Finite Element Analysis Of A Highly Flexible Flapping Wing,
2013
Air Force Institute of Technology
Finite Element Analysis Of A Highly Flexible Flapping Wing, Justin K. Mason
Theses and Dissertations
Small unmanned aerial systems are being designed to emulate the flapping kinematics of insects and birds which show superior control in slow speed regimes compared to fixed wing or rotorcraft aircraft. The flight of flapping wing vehicles is characterized by aeroelastic effects. Most research has been dedicated towards understanding the aerodynamic side of the aeroelastic response with minimal effort spent towards validating the structural response. A finite element model of a wing from a commercial flapping wing vehicle was created to validate the structural response. Vacuum testing allowed the isolation of the inertial response for a direct comparison to the …
