Engineering Commons^™

Investigation Of The Flow Field And Associated Heat Transfer Within An Asymmetrical Leading Edge Jet Impingement Array, Jorge Torres

Electronic Theses and Dissertations

This thesis investigates the turbulent flow features present in asymmetrical leading edge jet impingement and their effects from a fluid and heat transfer prospective using both numerical and experimental techniques. The jet-centerline plane flow field was quantified experimentally through the non-intrusive experimental method of Particle Image Velocimetry (PIV), while an area average heat transfer was acquired via a traditional copper block method. The numerical element served to investigate how well the Reynolds Averaged Navier-Stokes (RANS) k-? SST turbulence model predicts the flow field and heat transfer within the leading edge and further investigate the results outside of the experimental scope. …

A Multi-Species Single-Led Hazardous Gas Sensor For Commercial Space Applications, Akshita Parupalli

Electronic Theses and Dissertations

In the interest of furthering both commercial and government-funded opportunities for deep space exploration, the safety of life and equipment onboard must be absolutely certain. In this regard, the presence of any hazardous gases or combustion events onboard space vehicles must be quickly characterized and detected. Several hazardous gases of interest have absorption features in the mid-infrared range and can be detected with an infrared light source, via the principles of absorption spectroscopy. A non-dispersive infrared (NDIR) sensor that follows these principles has been developed to utilize light-emitting diodes (LEDs) for gas detection and quantification. LEDs contain a particular advantage …

Sintering Behavior, Structural, And Catalytic Properties Of Ytterbium Oxide (Yb2o3), Alina Aftab

Honors Undergraduate Theses

Ytterbia (Yb₂O₃) is an oxide ceramic, whose magnetic properties and crystal structure were studied to some extent in the past. However, the information on Yb₂O₃'s catalytic properties is lacking. Therefore, in this work, the sintering behavior and catalytic properties of Yb₂O₃ were examined. Yb₂O₃ ceramic samples were made using pressureless sintering of the commercially available Yb₂O₃ with 99.99% purity powder. The powder was first uniaxially pressed at 20 MPa in a steel die followed by pressureless sintering at different temperatures of 900 ⁰C …

Low Level Turbulence Detection For Airports, Anthony O' Connor, Derek Kearney

International Journal of Aviation, Aeronautics, and Aerospace

Abstract—— Low level wind shear and turbulence present a serious safety risk to aircraft during the approach, landing and take-off phases. Despite many advances in on-board and ground based warning systems. Wind shear remains a formidable force that coupled with a microburst can overpower any aircraft. Aviation reports have concluded that pilots need to have improved information in relation to tailwinds, wind shear and wind variations on approach and during the landing phases. Low level wind shear continues to cause disruption, delays and contribute to aircraft crashes. As recently as 2016, two Boeing aircraft crashed while attempting a Go-around …

3d Textile Preforms And Composites For Aircraft Strcutures: A Review, Abbasali Saboktakin

International Journal of Aviation, Aeronautics, and Aerospace

Over the last decades, the development of 3D textile composites has been driven the structures developed to overcome disadvantages of 2D laminates such as the needs of reducing fabrication cost, increasing through-thickness mechanical properties, and improving impact damage tolerance. 3D woven, stitched, knitted and braided preforms have been used as composites reinforcement for these types of composites. In this paper, advantages and disadvantages of each of them have been comprehensively discussed. The fabric architects and their specification in particular stitched preforms and their deformation mode for aerospace applications have been reviewed. Exact insight into various types of damage in textile …

Moore’S Law And Space Exploration: New Insights And Next Steps, Michael Howell, Venkat Kodali, Richard Segall, Hyacinthe Aboudja, Daniel Berleant

Journal of the Arkansas Academy of Science

Understanding how technology changes over time is important for industry, science, and government policy. Empirical examination of the capability of technologies across various domains reveals that they often progress at an exponential rate. In addition, mathematical models of technological development have proven successful in deepening our understanding. One area that has not been shown to demonstrate exponential trends, until recently, has been space travel.

This paper will present plots illustrating trends in the mean lifespan of satellites whose lifespans ended in a given year. Our study identifies both Wright’s law and Moore’s law regressions. For the Moore’s law regression, we …

Effect Of Perturbations On The Dominant Flow Structures In A Rectangular Lid-Driven Cavity With Particle Suspensions, Siva Bolisetty

Graduate Research Theses & Dissertations

The lid-driven cavity is a canonical problem in the field of analytical and computational fluid dynamics. This work is focused on a 2-D rectangular cavity with a length twice the size of its width and consists of an incompressible fluid with a moving upper wall/lid while the rest of the wall boundaries are subjected to fixed, no-slip, zero-velocity boundary conditions. The objective is to investigate the effect of perturbations resulting from particle drag and particle collisions on dominant flow structures of the fluid within this cavity. The dominant flow structures in a rectangular lid-driven cavity constitute a primary vortex, a …

An Investigation Of The Magneto-Active Slosh Control For Cylindrical Propellant Tanks Using Floating Membranes, Manikandan Vairamani, Pedro Llanos, Balaji Sivasubramanian, Somnath Nagendra, Kevin Crosby

Publications

The phenomenon of sloshing is a substantial challenge in propellant management, particularly in reduced gravity where surface tension-driven flows result in large slosh amplitudes and relatively long decay time scales. Propellant Management Devices (PMDs) such as the rigid baffles and elastomeric membranes are often employed to counteract motion of the free surface. In the present study, we investigate an active PMD that utilizes a free-floating membrane that, under an applied static magnetic field, becomes rigid and suppresses slosh. This semi-rigid structural layer can thereby replace bulky baffle structures and reduce the overall weight of the tank. In this paper, the …

Selective Dielectric Barrier Discharge Actuation For Flow Control Of Delta Wings, Arnab Chatterjee

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Impulse Measurements Of Electric Solid Propellant In An Electrothermal Ablation-Fed Pulsed Plasma Thruster, Matthew S. Glascock, Joshua L. Rovey, Kurt A. Polzin

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Electric solid propellants are advanced solid chemical rocket propellants that can be controlled (ignited, throttled and extinguished) through the application and removal of an electric current. These propellants are also being considered for use in the ablative pulsed plasma thruster. In this paper, the performance of an electric solid propellant operating in an electrothermal ablation-fed pulsed plasma thruster was investigated using an inverted pendulum micro-Newton thrust stand. The impulse bit and specific impulse of the device using the electric solid propellant were measured for short-duration test runs of 100 pulses and longer-duration runs to end-of-life, at energy levels of 5, …

Wake Vortex Pair Formation As An Analog For Dust Devil And Tornado Genesis, Robert L. Ash

Mechanical & Aerospace Engineering Faculty Publications

In 1966, meteorologist R.S. Scorer attempted to explain how large-scale oceanic tropical depressions become hurricanes or typhoons. His model was based on the idea that when these large-scale tropical depression structures begin to rotate, mostly due to Coriolis effects, an annular outer portion of that structure changes suddenly to a potential vortex segment, with the same outer radial limit as the low-pressure structure, but with an inner radius that conserves the overall system angular momentum and kinetic energy. By analogy with the "jump" instability describing sudden buckling of a vertical column, this paper shows that his conjecture merits additional consideration. …

Parametric Study Of A Turbofan Engine With An Auxiliary High-Pressure Bypass, Sharanabasaweshwara A. Asundi, Syed Firasat Ali

Mechanical & Aerospace Engineering Faculty Publications

A parametric study of a novel turbofan engine with an auxiliary high-pressure bypass (AHPB) is presented. The underlying motivation for the study was to introduce and explore a configuration of a turbofan engine which could facilitate clean secondary burning of fuel at a higher temperature than conventionally realized. The study was also motivated by the developments in engineering materials for high-temperature applications and the potential utility of these developments. The parametric study is presented in two phases. Phase I presents a schematic of the turbofan engine with AHPB and the mathematics of the performance parameters at various stations. The proposed …

An Experimental Approach That Assesses In-Situ Micro-Scale Damage Mechanisms And Fracture Toughness In Thermoplastic Laminates Under Out-Of-Plane Loading, H. Wafai, A. Yudhanto, G. Lubineau, R. Yaldiz, N. Verghese

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Studying the response of laminated composites under out-of-plane loading routinely involves mechanical tests, such as quasi-static indentation or impact. The phenomenology during these tests is so complex that it is difficult to identify different material properties related to each failure mechanism (damage mode). We aim at providing an experimental approach, which is practical and fast, for assessing the in-situ micro-scale damage mechanism and extracting the fracture toughness in thermoplastic laminates under out-of-plane loading. To this end, we developed a dedicated, micro-scale, three-point bending (micro-3PB) test fitted inside a scanning electron microscope (SEM). In a single experiment, we were able: (i) …

Oscillatory Flow Driven By Cavity, Jeremy Ralph Bonifacio

CGU Theses & Dissertations

Flows past a cavity are known to exhibit an oscillatory behavior with an amplitude and frequency dependent on the incoming flow properties and the geometry of the cavity. Experiments and numerical analyses have been performed to determine the effects of a flow passing through an axisymmetric cavity and discharging into a transverse freestream. The study focuses on the mechanisms involved in the generation of pulsatile flow and its influences on a jet in crossflow. Flow characteristics through the cavity and the jet in crossflow interaction were analyzed using the computational fluid dynamics software Siemens Star-CCM+. The experimental analysis utilized a …

Design And Testing Of A Wind Energy Harnessing System For Forced Convective Drying Of Grain In Low Wind Speed, Warm And Humid Climates, Francis Akumabi Agbali

Theses and Dissertations--Biosystems and Agricultural Engineering

Forced convective drying using a wind turbine mechanically connected to a ventilation fan was hypothesized for low cost and rapid grain drying in developing countries. The idea was tested using an expandable wind turbine blade system with variable pitch, at low wind speeds in a wind tunnel. The design was based on empirical and theoretical models embedded in a graphical user interface (GUI) created to estimate airflow-power requirements for drying ear corn. Output airflow (0.0016 - 0.0052 m³kg^-1s^-1) increased within the study wind speed range (2.0 - 5.5 m/s). System efficiency peak (8.6%) was …

Enhanced Surface Integrity With Thermally Stable Residual Stress Fields And Nanostructures In Cryogenic Processing Of Titanium Alloy Ti-6al-4v, James R. Caudill

Theses and Dissertations--Mechanical and Aerospace Engineering

Burnishing is a chipless finishing process used to improve surface integrity by severe plastic deformation (SPD) of surface asperities. As surface integrity in large measure defines the functional performance and fatigue life of aerospace alloys, burnishing is thus a means of increasing the fatigue life of critical components, such as turbine and compressor blades in gas turbine engines. Therefore, the primary objective of this dissertation is to characterize the burnishing-induced surface integrity of Ti-6Al-4V alloy in terms of the implemented processing parameters. As the impact of cooling mechanisms on surface integrity from SPD processing is largely unexplored, a particular emphasis …

Single-Degree-Of-Freedom Experiments Demonstrating Electromagnetic Formation Flying For Small Satellite Swarms Using Piecewise-Sinusoidal Controls, Ajin Sunny

Theses and Dissertations--Mechanical and Aerospace Engineering

This thesis presents a decentralized electromagnetic formation flying (EMFF) control method using frequency-multiplexed sinusoidal control signals. We demonstrate the EMFF control approach in open-loop and closed-loop control experiments using a single-degree-of-freedom testbed with an electromagnetic actuation system (EAS). The EAS sense the relative position and velocity between satellites and implement a frequency-multiplexed sinusoidal control signal. We use a laser-rangefinder device to capture the relative position and an ARM-based microcontroller to implement the closed-loop control algorithm. We custom-design and build the EAS that implements the formation control in one dimension. The experimental results in this thesis demonstrate the feasibility of the …

Design Process For The Containment And Manipulation Of Liquids In Microgravity, Chris Meek

Theses and Dissertations--Mechanical and Aerospace Engineering

In order to enhance accessibility to microgravity research, the design process for experiments on the ISS must be streamlined and accessible to all scientific disciplines, not just aerospace engineers. Thus, a general design and analysis toolbox with accompanying best practices manual for microgravity liquid containment is proposed. The work presented in this thesis improves the design process by introducing a modular liquid tank design which can be filled, drained, or act as a passive liquid-gas separation device. It can also be pressurized, and used for aerosol spray. This tank can be modified to meet the design requirements of various experimental …

Hybrid Multi-Objective Optimization Of Left Ventricular Assist Device Outflow Graft Anastomosis Orientation To Minimize Stroke Rate, Blake Lozinski

Electronic Theses and Dissertations

A Left Ventricular Assist Device (LVAD) is a mechanical pump that is utilized as a bridge to transplantation for patients with a Heart Failure (HF) condition. More recently, LVADs have been also used as destination therapy and have provided an increase in the quality of life for patients with HF. However, despite improvements in VAD design and anticoagulation treatment, there remains a significant problem with VAD therapy, namely drive line infection and thromboembolic events leading to stroke. This thesis focuses on a surgical maneuver to address the second of these issues, guided by previous steady flow hemodynamic studies that have …

Numerical Simulation Of Non-Premixed And Premixed Axial Stage Combustor At High Pressure, Tyler Worbington

Electronic Theses and Dissertations

Axial-staged combustors represent an important concept that can be applied to reduce NOx emissions throughout a gas turbine engine. There are four main CFD models presented in this study that describe a highly turbulent jet-in-crossflow (JIC) simulation of partially premixed and non-premixed jets with a constant chamber pressure of 5 atm absolute. The equivalence ratio of the partially premixed jet was held constant at rich conditions with a �������� of 4 while the main stage varied from ��1 and ��2 of 0.575 and 0.73 with an average headend temperature of 1415K and 1545K, respectively. Chemistry was reduced by tabulation of …

Development And Environmental Testing Of A Single-Axis Printer Inside A 1u Cubesat For On-Orbit Servicing Repairs In Low Earth Orbit, Perla Rocio Perez

Open Access Theses & Dissertations

As additive manufacturing is becoming an established technology in space, new emerging strategies improve the efficiency of the printing processes. Orbital Factory 2 (OF-2) is a small satellite-or CubeSat-developed at the University of Texas at El Paso (UTEP) which launched to space on November 2019. In January 2020, it will be released in low earth orbit (LEO). OF-2 is a 1U (10x10x10cm) CubeSat that carries a one-axis printer experiment as its primary payload. This printer was developed and tested in-house. The experiment focuses on printing electrically conductive ink on a printing circuit board that verifies the conductivity on the trace …

Beyond 2020 Nextgen Compliance: Human Factors And Cognitive Loading Issues For Commercial And General Aviation Pilots, Mark D. Miller, Sam Holley

Publications

As previously identified by the authors, digitized flight decks have realigned SHELL model components and introduced cognitive overload con­cerns. Considering changes from implementing Next Generation air traffic management requirements in 2020, the authors assess digitized interfaces associated with cockpit displays of information integral to performance based navigation and similar operations. Focus is placed on Automatic Dependent Surveillance Broadcast, digitized communications, and expanded electronic flight bags. The ADSB (In) cockpit display will enable pilots to have flight visual awareness on aircraft, terrain, weather and hazards to flight through live satellite updates every second. Increased optical demands and cognitive loading are anticipated …

A Change In The Dark Room: The Effects Of Human Factors And Cognitive Loading Issues For Nextgen Tracon Air Traffic Controllers, Mark D. Miller, Sam Holley, Bettina Mrusek, Linda Weiland

Publications

By 2020 all aircraft in United States airspace must use ADS-B (Automatic Dependent Surveillance-Broadcast) Out. This is a key component of the Next Generation (NextGen) Air Transportation System, which marks the first time all aircraft will be tracked continuously using satellites instead of ground-based radar. Standard Terminal Automation Replacement System (STARS) in the Terminal Radar Approach Control (TRACON) is a primary NextGen upgrade where digitized automation/information surrounds STARS controllers while controlling aircraft. Applying the SHELL model, the authors analyze human factors changes affecting TRACON controllers from pre-STARS technology through NextGen technologies on performance. Results of an informal survey of STARS …

The Application Of Signal Detection Theory Principles To Aircraft Certification, John M. Maris Ph.D, Alexander V. Ilyin Ph.D

International Journal of Aviation, Aeronautics, and Aerospace

This paper presents the application of Signal Detection Theory (SDT) concepts to the certification of optional systems that provide operational or system safety benefits. The method and analysis yield quantitative requirements for the system performance that account for the risks and benefits of the potential system. This is in contrast to the standard certification approach which only focuses on Failure Conditions, and does not examine potential system benefits. A case study of an aircraft spotter on an electronic moving map illustrates that substantial safety improvements may be achieved even with the relatively low levels of software reliability associated with Commercial …

Fe Modeling Methodology For Load Analysis And Preliminary Sizing Of Aircraft Wing Structure, Jun Hwan Jang, Sang Ho Ahn

International Journal of Aviation, Aeronautics, and Aerospace

It is a critical part at the basic design phase of aircraft structural design to build a finite element model and it will have a direct impact on time and cost for airframe structure development. In addition, the objective of finite element model will be varied depending on each design review phase and the modelling methodology varied accordingly. In order to build an effective and economic finite element model, it is required to develop adequate level of modelling methodology based on each design phase and its objectives. Therefore, in this paper, the finite element modeling methodology was presented for internal …

Comparison Of Fixed-Wing Unmanned Aircraft Systems (Uas) For Agriculture Monitoring, Joseph Cerreta, Kristine M. Kiernan

International Journal of Aviation, Aeronautics, and Aerospace

Florida citrus growers need inexpensive methods to observe citrus plants to detect disease and stress consistently. Health vegetation indices, such as the Normalized Difference Vegetation Index (NDVI) collected from Unmanned Aircraft Systems (UAS), can be used to identify variation in plant health. Simple-to-operate UAS may enable growers to determine within-field variation more frequently than with inspections from scouts, providing more frequent knowledge about the crop condition. This research compared two low-cost fixed-wing UAS, a $5,000 Parrot Disco Pro Ag and a $16,690 senseFly eBee, each equipped with a Parrot Sequoia multispectral camera, to determine if there were differences in the …

In-Flight Wingtip Folding: Inspiration From The Xb-70 Valkyrie, Gaétan X. Dussart, Mudassir Lone, Ciaran O'Rourke, Thomas Wilson

International Journal of Aviation, Aeronautics, and Aerospace

Wingip folding can be used to extend aircraft wingspan, allowing designers to take advantage of reduced induced drag whilst respecting ground operational limitations. Such devices can also be used in-flight for a variety of other benefits including load alleviation and flight control. The majority of in-flight folding research takes inspiration in past developments made on the XB-70 Valkyrie, which used the folding devices for stability and lift performance benefits. In this paper, the authors investigate the capabilities of the folding wingtip system and potential scaling to large civil aircraft. Manufacturing details are used to size the actuators whilst the aerodynamic …

Effects Of A Hand Luggage Guiding System On Airplane Boarding Time And Passenger Experience, Mirte Vendel, Sagar Dangal, Jessica Coppens, Suzanne Hiemstra-Van Mastrigt, Peter Vink

International Journal of Aviation, Aeronautics, and Aerospace

This research investigates whether a hand luggage guiding system in overhead bins decreases boarding time and improves boarding experience during aircraft boarding process. A guiding system was developed which allocates and displays the passengers luggage space in the overhead bin. The allocated space is guided by a light strip in front of the display that blinks when a passenger comes close to their allocated luggage space. This system was tested in a Boeing 737 test fuselage. Compared to regular boarding, a boarding time reduction of 16 to 23 seconds was estimated using the hand luggage guiding system in groups of …

Global Aviation System: Towards Sustainable Development, Marina P. Bonser Dr.

International Journal of Aviation, Aeronautics, and Aerospace

Aviation around the world has integrated into a global system. As the integration process continues, more aspects and levels of it need to be lead towards the sustainable development of the whole system via advancing strategic management, global communication proficiency, and technological expertise. It becomes essential to enrich global language (English) proficiency with cross-cultural communication competence not only for communication in the air but also for airport security, passenger and cargo services, aircraft and equipage engineering, building, and maintenance. Nowadays lower levels of management need more advanced strategic thinking and problem solving skills, and higher levels of management need global …

Determination Of Parameters During Quasi-Steady Stall Maneuver Using Genetic Algorithm, Ambuj Srivastava, Ajit Kumar, Ajoy Kanti Ghosh

International Journal of Aviation, Aeronautics, and Aerospace

The current work offers the determination of longitudinal aerodynamic derivatives during flight manoeuver at angles of attack near the stall. The flight manoeuver near stall is highly non-linear in nature due to separated flow at such elevated angles of attack. Kirchoff’s model for Quasi-Steady Stall Modelling (QSSM) is employed to represent the non-linear nature of aerodynamics during flight manoeuver at elevated angles of attack close to the stall. The Genetic Algorithm (GA) optimized output error method is utilized for estimating the parameters specific to stall characteristics and longitudinal aerodynamics of the ATTAS aircraft. The comparative evaluation of the parameter estimates …