Aerospace Engineering Commons^™

Scalloped Leading Edge Vaned Diffuser Analysis For A Compact High Pressure Ratio Centrifugal Compressor, Vinod Poonamchand Gehlot

Doctoral Dissertations and Master's Theses

Microturbines and small gas turbines are often an attractive option for turbo-hybrid application research in aviation due to their simple design and high power to weight ratio. However, the low operating pressure ratios of microturbines leads to low thermal efficiency, which results in very high fuel consumption. Higher operating pressure ratios in microturbines could vastly improve their current fuel efficiency. This thesis focuses on developing a compact, single stage 8:1 pressure ratio centrifugal compressor stage designed to meet the high-pressure ratio requirements of microturbines and small gas turbine engines in turbo hybrid-electric propulsion applications. The first stage vaned diffuser was …

Benchmarking Of Computational Models Against Experimental Data For Adiabatic Film-Cooling Effectiveness For Large Spacing Compound Angle Full Coverage Film Cooling Arrays, Simon R. Martinez

Doctoral Dissertations and Master's Theses

This study aims to benchmark experimental data that tested the effects of blowing ratio, surface angle, and hole spacing for two full coverage geometries composed of cylindrical staggered holes at a compound angle of 45 degrees. These holes varied parametrically the inclination angle to be 30 and 45 degrees, while maintaining a lateral and axial spacing of 14.5 hole diameters. Within this study, the local film cooling effectiveness was obtained from 30 rows for the 14.5 diameter spacing. Utilizing a velocity profile at the crossflow inlet produced significant differences in the results produced when compared to a uniform freestream velocity …

Investigation Of Pulse Detonation Engines: The Effect Of Variable Blockage Ratio On The Deflagration To Detonation Transition, Christopher Tate

Doctoral Dissertations and Master's Theses

Detonation and constant volume combustion is well known to be thermodynamically more efficient than the typically utilized constant pressure. There have been numerous approaches of achieving detonation through deflagration-to-detonation transition most of which use evenly spaced obstacles with a specified constant blockage ratio to generate turbulence and pressure fluctuations. There have been few efforts to study effects of varying blockage ratio as a function of axial distance. This research analyzes the effect of variable blockage ratio on deflagration-to-detonation transition in ethylene-air mixtures. The experiments show that with certain blockage ratio functions detonation is more repeatable and produces a smaller variation …

Analysis Of A Hybrid Rocket Burn Using Generalized Compressible Flow, Naveen Sri Uddanti

Doctoral Dissertations and Master's Theses

The analysis of square ports in a hybrid rocket is simple when compared to other complicated port geometries such as a wagon wheel configuration. In the present work, fuel grains with several ports in a hybrid rocket engine are analyzed by transforming the ports into equivalent square ports. As an example, the internal ballistics of a hybrid rocket with circular ports is analyzed by transforming it to an equivalent solid grain with square ports having the same amount of solid fuel and burn time. The results obtained are similar to that of circular port but with a slight decrease in …

Comparing Different Methods For Estimating Total Open Heliospheric Magnetic Flux, Samantha J. Wallace

Doctoral Dissertations and Master's Theses

There are extended periods over the solar cycle where significant discrepancies occur between the observed open magnetic flux (i.e., those based on spacecraft observations) and that determined from coronal models. One explanation for the source of these discrepancies is the magnetic fields in CMEs, which have yet to magnetically disconnect from the Sun. These “closed” flux sources can be included in open flux estimates, because open and closed magnetic field lines are not easily distinguished in spacecraft data. Another possibility is that a portion of the open flux measured by in situ spacecraft originates from the time-dependent evolution of solar …

Comparison Of Aircraft Tire Wear With Initial Wheel Rotational Speed, Abdurrhman A. Alroqi, Weiji Wang

International Journal of Aviation, Aeronautics, and Aerospace

The impact an aircraft has on its tires when it lands has been problematic practically since the invention of the airplane. Upon touchdown, the tires frequently smoke as rubber burns off and tire material is worn away while the tires slip up to a steady rolling speed. To minimise tire slip, torque or spin mechanisms could be added to each tire assembly to accelerate the tire to match the landing speed. Patents have been registered since the 1940s to improve tire safety and performance, decrease the substantial wear that results from every landing, and save airline companies the cost of …

Aircraft De-Icing System Using Thermal Conductive Fibers, Min Soon Park

Doctoral Dissertations and Master's Theses

The accumulation of ice on the leading edges of aircraft wing poses complications for flight control as drag is increased with a tendency for higher relative turbulence over the wing. Pre-emptive and reactive ice removal techniques have been employed in the past by electromechanical, thermal, chemical and pneumatic methods. In this thesis, a carbon fiber fabric is utilized as a heating de-icer for composites aircraft wing surface structures. Two prototypes are constructed, tested to generate temperature profiles, and an appropriate heating voltage is selected for effective de-icing via distinct avenues of heating system configurations. The heat transfer efficiency of the …

Efficient General Computational Method For Estimation Of Standard Atmosphere Parameters, Nihad E. Daidzic Ph.D., Sc.D.

International Journal of Aviation, Aeronautics, and Aerospace

Knowledge of standard air temperature, pressure, density, speed of sound, and viscosity as a function of altitude is essential information in aircraft design, performance testing, pressure altimeter calibration, and several other aeronautical engineering and aviation science applications. A new efficient computational method for rapid calculations of standard atmospheric parameters up to 86 orthometric km is presented. Additionally, mass and weight of each standard atmospheric layer were calculated using a numerical integration method. The sum of all fractional masses and weights represents the total mass and weight of Earth’s atmosphere. The results obtained here agree well with measurements and models of …

Economic Interrelationships And Impacts Of The Aviation/Aerospace Industry In The State Of Florida Using Input-Output Analysis, Kelly A. Whealan-George

Doctoral Dissertations and Master's Theses

The study provided a detailed description of the interrelatedness of the aviation and aerospace industry with principal industries in Florida and Volusia County (VC) using Input-Output (IO) analysis. Additionally, this research provided an economic impact analysis of the creation of a university research park in Daytona Beach (DB). The economic impact measures included not only direct economic output and industry employment descriptions but also described the multiplier effects in the form of indirect and induced impacts using data for 2012.

This research concluded the average labor income of the aviation and aerospace industry was higher than average labor income in …

Suborbital Spaceflight: A Student Team’S Plan To Send A Rocket To Space, Bryce Chanes, William Carpenter, Julio Benavides, Matthew Haslam, Brenda Haven

Aviation / Aeronautics / Aerospace International Research Conference

The Eagle Space Flight Team was created with the goal of becoming the first undergraduate team to design, build, and launch a rocket capable of suborbital spaceflight. In order to achieve this goal, the team will have to design a rocket capable of atmospheric flight at speeds over Mach 5 and launch it on one of the largest amateur rocket motors ever made. Over the next three years, the team will progress towards accomplishing this feat through a series of incremental test flights. Before the space flight, the team will build three sub-scale rockets designed to reach altitudes of 30,000’, …

Atmospheric Weather Balloon For Near Space Research, Francisco F. Pastrana, Devonte Grantham, Shane M. Williams, Jessy Law, Jennifer Nason, Janet Marrnane

Aviation / Aeronautics / Aerospace International Research Conference

Atmospheric Weather Balloon for Near Space Research

The Society for S.P.A.C.E. has been working on the development of a weather balloon that will reach a height of 80 to 100 thousand feet and will collect data from the atmosphere. The weather balloon is attached to a Styrofoam box that contains an Arduino board controlling a set of sensors that will measure: temperature, humidity, atmospheric pressure, wind speed and direction.

The data will be collected and transmitted through an Xbee antenna that will provide us with remote monitoring capabilities. The data and images gathered will aid understanding of the characteristics and …

Autonomous Satellite Recovery Vehicle, William Lewis, Devonte Grantham, Francisco Pastrana, Shane Williams, Joshua Moffett, Jessy Law, Kyle Ouellette, Janet Marnane

Aviation / Aeronautics / Aerospace International Research Conference

In collaboration with ERFSEDS, we would like to send a small satellite attached to a quad-copter as the payload for ERFSEDS rocket which will reach an altitude of 10,000 feet. The quad-copters objective will be to collect atmospheric data as it descends. Our plan is to 3-D print a new chassis for the quad-copters electronic components and arms that will allow the quad-copter to fold its arms inwards to meet the required space constraints. After launching the rocket, the satellite will be deployed at the target altitude and begin collecting data once jettisoned from the rocket. Once reaching 2,000 feet …

Microcontrollers In The Aviation Classroom, Padraig Houlahan

Aviation / Aeronautics / Aerospace International Research Conference

Modern commercial aircraft are increasingly dependent on digital technologies that detect sensor data and pilot control movements, interpret them, and then issue appropriate control signals to remote motors that move control surfaces. Because such technologies are innately complex, it would appear there is an unacceptably large academic burden on introducing them into the undergraduate pilot's curriculum .

However, in recent years there has been an explosion of interest in using micro-controllers in academic teaching (high-school and undergraduate levels) and in hobby applications, resulting in a large, online, freely available knowledgebase of techniques and solutions. Here, I demonstrate how easy it …

Unlocking The Mysteries Of Flight: From The Top Down, Juan Merkt

Aviation / Aeronautics / Aerospace International Research Conference

Traditionally, principles of flight are taught from the bottom-up. That is, we start by examining underlying causes (properties of air) and later move up to top consequences (aircraft performance). This traditional approach is analogous to that used by airplane designers and is most obvious in theory of flight textbooks for pilots. The problem with a bottom-up approach is that it introduces basic concepts as isolated “parts” without providing a “big picture” context. This can lead to poor understanding among student pilots. I suggest an opposite approach. Rather than starting with the underlying causes of flight, we can unravel basic principles …

Low Fidelity Flight Simulation In Collegiate Aviation, Vladimir N. Risukhin

Aviation / Aeronautics / Aerospace International Research Conference

Aviation college pilot training programs, lessons and exercises contain portions that do not require training in sophisticated and highly expensive full flight simulators and flight training devices (FTD) with high fidelity of simulation, or in real aircraft flights. Relatively inexpensive personal-computer-based flight simulation facilities named low fidelity simulators (LFS) can boost development of aircraft pilots’ cognitive and behavioral skills. The paper attempts to reveal how the LFS can support aviation college flight training and research activities. In the Western Michigan University College of Aviation, peer mentoring technique proven to be helpful in higher education institutions has been applied to flight …

Thinking Rather Than Panicking About The Current Drone Threat, Tom Foley, Tyrone Groh

Aviation / Aeronautics / Aerospace International Research Conference

Originally titled "UAS Threats in Sport Venues," the authors opted to expand their focus to better to all threats from UASs, and to encourage better preparation for and responses to such threats. Foley and Groh discuss different strategies.

Developing A Robust Balance For Wingsuit Aerodynamic Research, Timothy A. Sestak

Aviation / Aeronautics / Aerospace International Research Conference

Research on wingsuit aerodynamics requires specialized wind tunnel equipment. There is the potential for the relatively large ram-air inflated fabric airfoils being examined to flap and oscillate uncontrolled in the wind tunnel airflow. This chaotic combination of motion and forces could damage the fragile precision balances currently used. Due to the relatively recent development of wingsuit flight as an active sport, there is very little background literature on wingsuit aerodynamics, wingsuit testing, and the equipment and sensors required. A new balance design, able to accurately measure and record basic lift and drag forces while also being able to withstand the …

Human Factors Considerations In Autonomous Lethal Unmanned Aerial Systems, Kristine Kiernan

Aviation / Aeronautics / Aerospace International Research Conference

The United States military is committed to the development of complete autonomy in unmanned vehicles, including armed unmanned aerial systems (UAS). The design and deployment of autonomous lethal UAS raises ethical issues that have implications for human factors. System design, procedures, and training will be impacted by the advent of autonomous lethal UAS. This paper will define relevant vocabulary, review the literature on robot ethics as it applies to the military setting, discuss various perspectives in the research community, address levels of UAS autonomy, and discuss implications for operator training, responsibility, and human-machine interaction. Familiarity with these ethical issues and …

Insights Into Uas Accidents And Incidents, Robert Joslin

Aviation / Aeronautics / Aerospace International Research Conference

The proliferation and extension of unmanned aircraft systems from military to civil and public use applications has rapidly outpaced the safety analysis that is normally associated with the introduction of a new and novel aircraft. Insights into the types of anomalous events associated with accidents and incidents involving civil and public use unmanned aircraft systems operating in the National Airspace System were derived from an information synthesis of archival publically available reports from the FAA Preliminary Reports of Unmanned Aircraft System Accidents and Incidents database, as recorded in the Aviation Safety Information and Analysis Sharing system. The vast majority of …

Cubesat Wakes In The Earth’S Ionosphere, Robert M. Albarran Ii

Doctoral Dissertations and Master's Theses

Space exploration is currently being revolutionized by the advent of the CubeSat: 10cm cubed satellites that typically deploy in constellations for less than $100,000. Spacecraft instrumentation design must be redefined to abide by the compact CubeSat payload. Furthermore, the CubeSat dimension must be considered with respect to characteristic length scales of the space plasma environment, namely, the Debye length. Although spacecraft-plasma interactions- surface charging, plasma sheaths and wakes- have been well-studied for larger satellites, they are less understood for CubeSats.

The Dynamic Ionosphere CubeSat Experiment (DICE) is a 1.5U CubeSat which recently ended its mission. DICE carried two fixed-bias Langmuir …

Proof Of Concept Test For Dual-Axis Resonant Phase-Locked Excitation (Phlex) Fatigue Testing Method For Wind Turbine Blades, Jenna Austin Beckwith

Doctoral Dissertations and Master's Theses

The installed capacity of wind turbines has grown steadily for the past decade with wind energy now providing 3.6-percent of the U.S.’s electricity supply [13]. This trend can be attributed to advancements in wind turbine technology and the ability to increase wind turbine sizes. As wind turbines grow in size, so do the loads experienced by the turbine. One of the most significant load increases is in the lead-lag direction of the wind turbine blades. The increase in lead-lag load is due to the increase in weight of the larger blades. Current wind turbine blades have lead-lag and flapwise loads …

Vision-Aided Navigation For Gps-Denied Environments Using Landmark Feature Identification, Tennyson Samuel John

Doctoral Dissertations and Master's Theses

In recent years, unmanned autonomous vehicles have been used in diverse applications because of their multifaceted capabilities. In most cases, the navigation systems for these vehicles are dependent on Global Positioning System (GPS) technology. Many applications of interest, however, entail operations in environments in which GPS is intermittent or completely denied. These applications include operations in complex urban or indoor environments as well as missions in adversarial environments where GPS might be denied using jamming technology.

This thesis investigate the development of vision-aided navigation algorithms that utilize processed images from a monocular camera as an alternative to GPS. The vision-aided …

Development Of An Exteroceptive Sensor Suite On Unmanned Surface Vessels For Real-Time Classification Of Navigational Markers, Christopher Lloyd Kennedy

Doctoral Dissertations and Master's Theses

This thesis presents the development of an exteroceptive sensor suite for real-time detection and classification of navigational markers on Unmanned Surface Vessels. Three sensors were used to complete this task: a 3D LIDAR and two visible light cameras. First, all LIDAR points were transformed from the sensor’s reference frame to the local frame using a Kalman filter to estimate instantaneous vehicle pose. Next, objects were chosen from the LIDAR data to be classified using either Multivariate Gaussian or Parzen Window Classifiers. Both produce 96% accuracy or better, however, multivariate Gaussian ran considerably faster than the Parzen and was simpler to …

Design And Dynamic Analysis Of A Variable-Sweep, Variable-Span Morphing Uav, Nirmit Prabhakar

Doctoral Dissertations and Master's Theses

Morphing wings have the potential to optimize UAV performance for a variety of flight conditions and maneuvers. The ability to vary both the wing sweep and span can enable maximum performance for a diverse range of flight regimes. For example, low-speed missions can be optimized using a wing with high aspect ratio and no wing sweep whereas high-speed missions are optimized with low aspect ratio wings and large wing sweep. Different static morphing wing configurations clearly result in varying aerodynamics and, as a result, varying dynamic modes. Another important consideration, however, is the transient dynamics that occur when transitioning between …

Fatigue Damage Prognosis Of Internal Delamination In Composite Plates Under Cyclic Compression Loadings Using Affine Arithmetic As Uncertainty Propagation Tool, Audrey J-M Gbaguidi

Doctoral Dissertations and Master's Theses

Structural health monitoring (SHM) has become indispensable for reducing maintenance costs and increasing the in-service capacity of a structure. The increased use of lightweight composite materials in aircraft structures drastically increased the effects of fatigue induced damage on their critical structural components and thus the necessity to predict the remaining life of those components. Damage prognosis, one of the least investigated fields in SHM, uses the current damage state of the system to forecast its future performance by estimating the expected loading environments. A successful damage prediction model requires the integration of technologies in areas like measurements, materials science, mechanics …

Development, Analysis, And Comparison Of Electromechanical Properties And Electrode Morphology Of Ionic Polymer Metal Composites, Balaji Sivasubramanian

Doctoral Dissertations and Master's Theses

With smart materials and adaptive structures being nudged into mainstream technology progressively, the smart composites are donning a predominant role as indispensable structures. Among these, the Ionic Polymer Metal Composites (IPMC), with their large bending deformation and relaxation characteristics at very low voltages are attractive as transducers in many areas of application. The actuation and sensing properties of IPMC have been sought after for various engineering functions. The paper focuses on manufacturing various types of IPMC. Combining the ionic polymer with platinum electrodes, gold sputter coated electrodes and multi-walled carbon nanotube Bucky paper electrodes to create enhanced IPMCs, comparative analysis …

Achieving Global Range In Future Subsonic And Supersonic Airplanes, Nihad E. Daidzic Ph.D., Sc.D.

International Journal of Aviation, Aeronautics, and Aerospace

No commercial airplane in service today is able to fly half great-circle distances over the globe and achieve the non-stop or the global range to any antipodal location on Earth. A subsonic jetliner has the optimum cruising speed at Mach numbers approaching the drag divergence Mach number while still preserving relatively high aerodynamic efficiency. Various fuel-flow laws were used to investigate the cruise performance of subsonic and supersonic aircraft. The effect of wind and aircraft weight and how it affects the optimal cruising airspeed was investigated. Of all different operational cruising techniques, the cruise-climb at high Mach numbers is the …

The History Of Space Debris, Loretta Hall

Space Traffic Management Conference

This paper examines what space debris consists of and where it came from. In 1958, astronomer Clyde Tombaugh published the results of his research into the existence of natural debris near the Earth, concluding that no such debris existed. During the ensuing fifty-five years, man-made debris has been accumulating to the point that it threatens launches, active satellites, and the International Space Station. NASA reported that as of 2013, more than 21,000 pieces the size of a softball or larger were being tracked, as were about 500,000 pieces at least the size of a marble and “many millions” of pieces …

An Integrated Approach To Orbital Debris Research And Management, Marshall H. Kaplan

Space Traffic Management Conference

A viable space traffic management program faces a great barrier caused by the ever-increasing number and variety of orbiting objects ranging in size from a few microns to several meters. Although several international agreements to limit the growth rate of orbital debris are in place, the risk of damage and destruction to active satellites is continually rising. The urgency of this situation was highlighted by the 2007 Chinese ASAT test and the collision of Iridium and Cosmos satellites in 2009. Although many debris removal techniques have been posited none have been implemented. Unless a space debris reduction program is undertaken …

Where Is Space? And Why Does That Matter?, Bhavya Lal, Emily Nightingale

Space Traffic Management Conference

Despite decades of debate on the topic, there is no consensus on what, precisely, constitutes the boundary between airspace and outer space. The topic is mired in legal and political conundrums, and the easy solution to-date has been to not agree on a definition of space. Lack of a definition, some experts claim, has not limited space-based activities, and therefore is not a hurdle that must be overcome. There are increasing calls however in light of increasing (and expectations of increasing) space traffic, both orbital and sub-orbital. This paper summarizes the proposed delimitation of space, the current debate on whether …