Aerospace Engineering Commons^™

Primary And Secondary Flow Structures In A Model Cerebral Aneurysm, Morgan A. Nowak

Renée Crown University Honors Thesis Projects - All

Cerebral aneurysms affect 5% of western populations and can cause morbidity and mortality if they rupture. Various treatments can be used to minimize the risk of rupture, with new diagnostics and treatments under development that require information from non-invasive techniques such as Particle Imaging Velocimetery (PIV). The current study focused on developing a setup as a basis for future experiments and work on intracranial aneurysms involving PIV. PIV experimentation and data collection were carried out during the summer of 2010 at Ohta Labs of Tohoku University in Sendai, Japan. The experimental setup consisted of a pulsatile flow system, which was …

A 6-Degree Of Freedom Static Thrust Stand Developed For Rc-Scale Jet Engines, Spencer Sessions

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The description of a portable 6-degree of freedom static thrust stand for RC-scale jet engines is reported. The stand includes three axial and three lateral load cells measuring static thrust with six degrees of freedom. A pitot probe with single axis position control placed perpendicular to exhaust flow measures stagnation pressure along the nozzle centerline. A pitot probe open to the inside of the engine nozzle normal to the exhaust flow and near the outlet measures static pressure. A digital scale measures fuel consumption. The engine is mounted with exhaust gases exiting upward avoiding ground effects and thrust acting downward. …

Computational Efficiency Of A Hybrid Mass Concentration And Spherical Harmonic Modeling, Nathan Piepgrass

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Through Spherical Harmonics, one can describe complex gravitational fields. However as the order and degree of the spherical harmonics increases, the computation speed rises exponentially. In addition, for onboard applications of spherical harmonics, the processors are radiation hardened in order to mitigate negative effects of the space environment on electronics. But, those processors have outdated processing speeds, resulting in a slower onboard spherical harmonic program.

This thesis examines a partial solution to the slow computation speed of spherical harmonics programs. The partial solution was to supplant the gravity models in the flight software. The spherical harmonics gravity model can be …

Electric Motor & Power Source Selection For Small Aircraft Propulsion, Jeremy Fehrenbacher, David L. Stanley, Mary E. Johnson Dr., Jeffrey Honchell

Purdue Polytechnic Directed Projects

The research conducted in this project is on electrical propulsion in aviation. A Cessna 172K aircraft with a Lycoming O-320-E2D piston engine serves as a baseline measurement. Investigation of the components required for electrical flight is performed, and components are selected based on market availability and operational performance criteria.

This research focuses on electrical propulsion in the aviation industry, and is tailored to aircraft within the General Aviation sector leading to the following research question: Can current electric motor and battery technologies conceptually support flight operations for a Cessna 172K in terms of aircraft performance criteria?

The results explore the …

Direct Numerical Simulation Of Hypersonic Turbulent Boundary Layers. Part 3. Effect Of Mach Number, L. (Lian) Duan, I. Beekman, M. P. Martín

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this paper, we perform direct numerical simulations (DNS) of turbulent boundary layers with nominal free-stream Mach number ranging from 0.3 to 12. The main objective is to assess the scaling's with respect to the mean and turbulence behaviors as well as the possible breakdown of the weak compressibility hypothesis for turbulent boundary layers at high Mach numbers (M > 5). We find that many of the scaling relations, such as the van Driest transformation for mean velocity, Walz's relation, Morkovin's scaling and the strong Reynolds analogy, which are derived based on the weak compressibility hypothesis, remain valid for the range …

Surface Geometry And Heat Flux Effect On Thin Wire Nucleate Pool Boiling Of Subcooled Water In Mictrogravity, Troy Munro, Heng Ban

Presentations

No abstract provided.

Thermal Conductivity Of Interfacial Layers In Nanofluids, Zhi Liang, Hai-Lung Tsai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Thermal Conductivity of Interfacial Layers is an Essential Parameter for Determining How the Ordered Liquid Layering Around the Particle-Liquid Interface Contributes to the Unusual High Thermal Conductivity of Nanofluids. However, So Far There is No Experimental Data Regarding This Parameter. using Nonequilibrium Molecular Dynamics Simulations of an Inhomogeneous Au-Ar System in Which the Solid-Liquid Interactions Are Assumed to Be Much Stronger Than the Liquid-Liquid Interactions, We Show Explicitly that the Thermal Conductivity of a 1-Nm-Thick Interfacial Layer is 1.6∼2.5 Times Higher Than that of the Base Fluid. the Simulation Results Are Incorporated into a Three-Level Clustering Model to Calculate the …

Some Considerations For Regional Airline Operations On Contaminated Runways., Nihad E. Daidzic

Aviation Department Publications

No abstract provided.

Neural Network Prediction Of Ultimate Compression After Impact Loads In Graphite-Epoxy Coupons From Ultrasonic C-Scan Images, Nikolas L. Geiselman

Master's Theses - Daytona Beach

The purpose of this project was to investigate how accurately an artificial neural network could predict the ultimate compressive loads of impact damaged 24-ply graphite-epoxy coupons from ultrasonic C-scan images. The 24-ply graphite-epoxy coupons were manufactured with bidirectional preimpregnated tape and cut into 21 coupons, 4 inches by 6 inches each. The coupons were impacted at known impact energies of 10, 12, 14, 16, 18, and 20 Joules in order to create barely visible impact damage (BVID). The coupons were then scanned with an ultrasonic C-scan system to create an image of the damaged area. Each coupon was then compressed …

Development Of Multidisciplinary Design Optimization Process For A Large Scale Hybrid Composite Wind Turbine Blade, Jin Woo Lee

Master's Theses - Daytona Beach

Development of a multidisciplinary design optimization (MDO) of a large scale hybrid composite wind turbine blade is performed. Multiple objectives are considered in the MDO process to maximize annual energy production and lifetime profit, minimize weight and power production rate. A wind turbine blade is divided into regions and the layup sequences for each region are considered as design variables. The scale of wind turbine blade is also considered to find the optimum size of a wind turbine blade. Applied loads due to extreme wind conditions for rotor rotation and rotor stop condition are considered for finite element analysis (FEA) …

Section Abstracts: Aeronautical And Aerospace Sciences

Virginia Journal of Science

Abstracts of the Aeronautical and Aerospace Sciences Section for the 89th Annual Meeting of the Virginia Academy of Science, May 25-27, 2011, University of Richmond, Richmond, Virginia.

Guidance, Navigation And Control Of A Fly-By-Wire Transport Category Airship Designed For Hover Cargo Delivery, Harshad H. Lalan

Master's Theses - Daytona Beach

The purpose of this thesis is to develop fly-by-wire pilot controls for a transport category airship propelled with six thrust vectoring engines, and to develop control laws to maintain position, heading, and attitude during hover and cargo operations. Owing to the large body area, most airships require that they be pointed into the wind to maintain their position. This research aims at controlling an airship attitude and position during hover cargo delivery, irrespective of the wind direction.

Control laws were developed for two primary modes of the airship: Flight (High Speed Mode) and Hover (Cargo Delivery Mode). Different sets of …

Conical Probe Calibration And Wind Tunnel Data Analysis Of The Channeled Centerbody Inlet Experiment, Samson Siu Truong

Aerospace Engineering

For a multi-hole test probe undergoing wind tunnel tests, the resulting data needs to be analyzed for any significant trends.  These trends include relating the pressure distributions, the geometric orientation, and the local velocity vector to one another.  However, experimental runs always involve some sort of error.  As a result, a calibration procedure is required to compensate for this error.  For this case, it is the misalignment bias angles resulting from the distortion associated with the angularity of the test probe or the local velocity vector.  Through a series of calibration steps presented here, the angular biases are determined and …

Investigation And Comparison Of Proportional Navigation Guidance And Beam Rider Guidance, Ertac Olgun

Electrical & Computer Engineering Theses & Dissertations

Air defense has an increasing importance in today's wars. To gain the advantage in air combat, pursuit interceptor aircraft, which use Air-to-Air Missiles (AAMs), have become more and more significant. However, these are not sufficient alone. The importance of Surface-to-Air Missiles (SAMs) also can not be ignored in air defense.

SAMs can use different tactical navigation guidance methods. Of these, two of the more important guidance methods are Proportional Navigation Guidance and Beam Rider Guidance, which are investigated in this thesis. To understand the idea better, a brief description and discussion of missiles are provided. Parts of the guided missiles …

Design And Demonstration Of A Miniature Lidar System For Rover Applications, Benjamin Robinson

Electrical & Computer Engineering Theses & Dissertations

Public awareness of harmful human environmental effects such as global warming has increased greatly in recent years and researchers have increased their efforts in gaining more knowledge about the Earth's atmosphere. Natural and man-made processes pose threats lo the environment and human life, so knowledge of all atmospheric processes is necessary. Ozone and aerosols are important factors in many atmospheric processes and active remote sensing techniques provide a way lo analyze their quantity and distribution.

A compact ground-based lidar system for a robotic platform meant for atmospheric aerosol measurements was designed, tested, and evaluated. The system will eventually be deployed …

Electronic Warfare By Using Unmanned Aerial Vehicles, Aydin Meric

Electrical & Computer Engineering Theses & Dissertations

Technology continues to evolve rapidly by the day. Developments in technology should be followed closely if a country wants to become more powerful. Nowadays nobody can afford to ignore the importance of Electronic Warfare and Unmanned Aerial Vehicles (UAV) in military applications. Both of them play a crucial role in military operations that they can change the course of a war.

There are different kinds of Electronic Warfare methods that can be applied according to the situations and any evolving circumstances. In the beginning Electronic Warfare was used mainly for defensive purposes, but these days Electronic Warfare is used for …

Unmanned Aerial Vehicles Collision Avoidance From Moving Obstacles, Atila Ozdemir

Electrical & Computer Engineering Theses & Dissertations

The usage of the unmanned aerial vehicles (UAV) is becoming more diverse day by day in both military and civil applications. Specifically in military applications, they are becoming a "must-have" component in every arsenal. Low cost, and especially the importance of human life, makes these vehicles desired in any military situation. But in order to take advantage of the UAVs, these vehicles should be able to navigate safely and not collide with other air vehicles, especially ones that are manned and carry personnel. As a result, the importance of a collision avoidance system of the UA V arises and begins …

Manipulating Particles For Micro- And Nano-Fluidics Via Floating Electrodes And Diffusiophoresis, Sinan Eren Yalcin

Mechanical & Aerospace Engineering Theses & Dissertations

The ability to accurately control micro- and nano-particles in a liquid is fundamentally useful for many applications in biology, medicine, pharmacology, tissue engineering, and microelectronics. Therefore, first particle manipulations are experimentally studied using electrodes attached to the bottom of a straight microchannel under an imposed DC or AC electric field. In contrast to a dielectric microchannel possessing a nearly-uniform surface charge, a floating electrode is polarized under the imposed electric field.

The purpose is to create a non-uniform distribution of the induced surface charge, with a zero-net-surface charge along the floating electrode's surface. Such a field, in turn, generates an …

Hydrostatic Pressure Testing Of A Square-Cross Section Stainless Steel Propellant Tank Manufactured Using Selective Laser Sintering, Spencer Fuller

Master's Theses - Daytona Beach

The purpose of this study was to determine if parts manufactured using metal selective laser sintering (SLS) exhibit the same isotropic material properties as conventionally made metal parts. This was accomplished by performing a hydrostatic pressure test (HPT) of a metal SLS manufactured propellant tank, constructed for a nano-satellite of the cubesat class. Strain measurements from twelve strain gage locations on the propellant tank were recorded. A finite element analysis (FEA) model, which assumes isotropic material properties, was generated and a FEA analysis was ran at several pressure loads. The tanks strain data at the corresponding pressure loads from the …

Ultimate Compression After Impact Load Prediction In Graphite/Epoxy Coupons Using Neural Network And Multivariate Statistical Analyses, Alexandre David Grégoire

Doctoral Dissertations and Master's Theses

The goal of this research was to accurately predict the ultimate compressive load of impact damaged graphite/epoxy coupons using a Kohonen self-organizing map (SOM) neural network and multivariate statistical regression analysis (MSRA). An optimized use of these data treatment tools allowed the generation of a simple, physically understandable equation that predicts the ultimate failure load of an impacted damaged coupon based uniquely on the acoustic emissions it emits at low proof loads. Acoustic emission (AE) data were collected using two 150 kHz resonant transducers which detected and recorded the AE activity given off during compression to failure of thirty-four impacted …

Preliminary Design Of An Asteroid Hopping Mission, Michael D. Scheppa

Doctoral Dissertations and Master's Theses

In 2010, NASA announced that its new vision is to support private space launch operations. It is anticipated that this new direction will create the need for new and innovative ideas that push the current boundaries of space exploration and contain the promise of substantial gain, both in research and capital.

The purpose of the study is to plan and estimate the feasibility of a mission to visit a number of near Earth asteroids (NEAs). The mission would take place before the end of the 21st century, and would only use commercially available technology. Throughout the mission design process, while …

A Pilot Model For Investigating Biodynamic Coupling Due To Aeroservoelastic Accelerations, Brandon Cowen

Mechanical & Aerospace Engineering Theses & Dissertations

Supersonic Transport Aircraft tend to have slender fuselages with respect to their subsonic counterparts. This design feature leads to increased aeroservoelastic bending at low resonant frequencies closer to the frequencies of pilot commands and the corresponding rigid body accelerations. Aeroelastic accelerations of certain frequencies and phase lags at the pilot station have been seen to involuntarily pass through the pilot's body to the control inceptor. When the pilot commands rigid body accelerations in phase with the structural response, the structural accelerations grow. Thus biodynamic coupling represents the coupling between the feedthrough of pilot station acceleration through the pilot's body, with …

Direct Current Electrokinetic Particle Transport In Micro/Nano-Fluidics, Ye Ai

Mechanical & Aerospace Engineering Theses & Dissertations

Electrokinetics has been widely used to propel and manipulate particles in micro/nano-fluidics. The first part of this dissertation focuses on numerical and experimental studies of direct current (DC) electrokinetic particle transport in microfluidics, with emphasis on dielectrophoretic (DEP) effect. Especially, the electrokinetic transports of spherical particles in a converging-diverging microchannel and an L-shaped microchannel, and cylindrical algal cells in a straight microchannel have been numerically and experimentally studied. The numerical predictions are in quantitative agreement with our own and other researchers' experimental results. It has been demonstrated that the DC DEP effect, neglected in existing numerical models, plays an important …

Ionic Current Rectification Phenomena In Asymmetrical Polymer Nanopores Under Salt Gradients, Murat Bakirci

Mechanical & Aerospace Engineering Theses & Dissertations

The magnitude of current through a conical nanopore filled with an electrolyte solution depends on the polarity of the applied bias, indicating an asymmetric diode-like current-voltage (I-V) curve. This kind of phenomenon refers to ionic current rectification (ICR), which is of interest because many ion-channel proteins in cellular membranes are rectifying. In addition, ICR in nanopores can be used to control ion concentrations in nano- and microfluidic systems. In this study, the ICR phenomenon through a conical nanopore simultaneously subjected to an electric field and salt concentration gradient is experimentally and numerically investigated.

The experiments were conducted in an Izon's …

Multidisciplinary Design Optimization Of Transonic Airfoil Sections Using Multiobjective Optimization And Computational Intelligence Tools, Amit A. Kulkarni

Mechanical & Aerospace Engineering Theses & Dissertations

The design of transonic airfoils for civil aviation applications has been a major engineering challenge in the last fifty years. This design problem arises due to the need to limit shock wave drag at a given transonic speed. In recent years, the requirement to reduce the levels of aircraft noise has started to affect the airfoil design process. The multidisciplinary aerodynamic shape optimization problem is treated in this thesis using a multi-objective approach. The objectives correspond to the design of transonic airfoil sections with low drag during cruise and low trailing edge noise levels during the approach condition. The optimization …

Potential Environmental Benefits Of Extending Aircraft Pushback Operations, Dennis R. O'Connell

Mechanical & Aerospace Engineering Theses & Dissertations

This study considered extending the operational use of pushback tractors to perform taxi-out airport ground operations for commercial aircraft as an alternative to using aircraft power plants for this operation. Pushback tractors are designed to reverse aircraft from the terminal gate to a position where the aircraft can taxi independently to the departure runway. In this investigation the process of pushback would be extended to pulling the aircraft to the departure runway then returning the pushback tractor to the terminal of origin, a new procedure known as extended pushback.

Data from major aircraft operators and engine manufacturers were collected to …

Interface Thermal Resistance Between Liquid Argon And Various Solids, Ziyuan Shi

Mechanical & Aerospace Engineering Theses & Dissertations

Heat conduction between two parallel solid walls separated by liquid argon is investigated using three-dimensional molecular dynamics (MD) simulations. Liquid argon molecules confined in silver and graphite nano-channels are examined separately. Heat flux and temperature distribution within the nano-channels are calculated by maintaining a fixed temperature difference between the two solid surfaces. Temperature profiles are linear sufficiently away from the walls, and heat transfer in liquid argon obeys the Fourier law. The temperature jump due to the interface thermal resistance (i.e., Kapitza length) is calculated by extrapolating the temperature profile in the bulk region on to the wall and is …

Surface Geometry And Heat Flux Effect On Thin Wire Nucleate Pool Boiling Of Subcooled Water In Microgravity, Troy Munro, Andrew Fassman

Presentations

The motivation of this nucleate boiling research is to understand the effects of surface geometry and heat flux as applied to a thin wire heater. This will further the understanding of the fundamental behaviors of boiling onset, steady state heat transfer, and bubble dynamics with respect to nucleate boiling with the goal of creating efficient thermal management systems for future space applications. Using three different thin platinum wire geometries and five different power levels, subcooled water was boiled over a period of approximately 30 seconds for 15 parabolic arcs to simulate microgravity. To represent the trends in bubbles behavior across …

Scale Modeling Of Cessna 172, Chee-Woon Kim

Aerospace Engineering

This report describes how the scale-model aircraft can be built when the Reynolds number is out of range for using dynamic similitude method. Due to lack of time and budget for designing an actual model for testing, Cessna 172 was used to calculate the size of the temporary scale-model aircraft. The method that was used for this project was matching aerodynamic coefficients such as drag coefficient or lift coefficient of the prototype and the model. Based on this method, the takeoff distance, landing distance and the rate of climb of the model came out to be 218 ft, 91 ft …

Characterization Of Horizontally-Issuing Reacting Buoyant Jets, Joshua J. Heffernen

Theses and Dissertations

This research studied the mixing and combustion behavior of low Reynolds number, horizontally-issuing gaseous fuel jets with ambient air. The study focused on the mixing characteristics of propane and ethylene. These fuels are, respectively, heavy and neutral with respect to air, and were tested at various Froude numbers and laminar tube Reynolds numbers. Using low Froude and Reynolds number flows allowed for isolation of the buoyant jet effects. The process was characterized through the use of a non-invasive, OH Planar Laser-Induced Fluorescence (PLIF) technique, and supplemented with filtered (CH*) and unfiltered high speed imaging. The resulting cross sectional PLIF images …