Aerospace Engineering Commons^™

An Experimental Investigation Of Direct And Indirect Viewing Of A Remote Manipulation, Stephen N. Plishka

Master's Theses - Daytona Beach

The purpose of this study was to evaluate direct and indirect viewing of a remote manipulation. With continued exploration of inner and outer space, the ability to directly manipulate objects is lost due to the nature of operating in harsh environments. Remote viewing and operation of equipment is used in such things as the space shuttle manipulator arm, orthoscopic surgery, undersea exploration, and hazardous material management. Most of these operations do not have the luxury of direct viewing. This study will compare the effects of direct viewing vs. indirect viewing from three different viewing distances of 20cm, 60cm and 100cm.

Acoustic Emission For Periodic Inspection Of Composite Pressure Vessels, Bao Rasebolai Mosinyi

Master's Theses - Daytona Beach

Cost savings can be achieved in a wide range of applications by replacing the current procedure for hydrostatic recertification of high-pressure composite gas cylinders with acoustic emission (AE) nondestructive testing. Advantages of AE recertification over the current hydrostatic method include: (1) no water contamination, since pressurization of the cylinders is done with air as opposed to water; (2) the risk of damage is decreased since the test pressure is reduced from 166% of design pressure to 110% of operating pressure; (3) the ability of acoustic emission to detect and locate flaws increases safety; and (4) the in-situ method will reduce …

Low Proof Load Prediction Of Ultimate Strengths Of Fiberglass/Epoxy I-Beams Using Acoustic Emission, Edward C. Fatzinger Jr.

Master's Theses - Daytona Beach

Acoustic emission (AE) nondestructive testing was used to monitor fiberglass/epoxy I-beams. The experiment consisted of loading the I-beams in cantilever fashion with a hydraulic ram. While testing, AE waveforms were collected from the onset of loading to failure. After acquisition, the AE data from each test were filtered to include only data collected up to 50% of the theoretical ultimate load for further analysis.

A Kohonen self-organizing map was utilized to separate each individual data point (hit) into failure mechanism clusters. Then a multiple linear regression analysis was performed using the percentage of hits associated with each failure mechanism along …

Design And Construction Of A 1/3-Scale, 1986 Cessna 172p Flight-Test Aircraft, Michael J. Hinton

Master's Theses - Daytona Beach

The incredible cost of prototype flight testing can be a very limiting factor in the optimization of new designs as they proceed from the drawing board to the flight line. The use of low-cost scaled models to predict full-scale prototype performance is the focus of this project. It will be shown that by strictly following geometric and dynamic scaling criteria, the scaled aircraft's flight performance can be predictably related to the full-scale aircraft's performance. Many companies have performed scaled flight-testing of Remotely Piloted Vehicles (RPV's) and there is much speculation as to the results of these tests, but non-proprietary information …

Solving Nonlinear Aeronautical Problems Using The Carleman Linearization Method, Brian William Gaude

Master's Theses - Daytona Beach

Many problems in aeronautics can be described in terms of nonlinear systems of equations. Carleman developed a technique to linearize such equations that could lead to analytical solutions of nonlinear problems. Nonlinear problems are difficult to solve in closed form and therefore the construction of such solutions is usually nontrivial. This thesis will apply the Carleman linearization technique to three model problems: a two-degree of-freedom (2DOF) ballistic trajectory, Blasius' boundary layer, and Van der Pol's equation and evaluate how well the technique can adequately approximate the solutions of these ordinary differential equations.

Optimization Of Flow Quality In The Test Section Of The 30-Inch X 40- Inch Subsonic Tunnel, Ahmed F. Elnenaey

Master's Theses - Daytona Beach

The purpose of this study is to optimize the flow quality inside the 30-inch x 40-inch subsonic wind tunnel. The tunnel is an open circuit with its inlet positioned adjacent to the side door of the lab; forcing the air to make a ninety degrees turn entering the tunnel. The flow suffered from two main deficiencies, high level of turbulence and slightly unsteady flow with a non-uniform velocity distribution across the test section. By utilizing a hot-film anemometer system and a total pressure rake, turbulence and velocity distribution data were obtained. Rounded corners and a turning vane were installed in …

Combined Loading Of Composite Box-Beams With Linearized Differential Equations Of Motion, Michael Alan Dupuis

Master's Theses - Daytona Beach

The purpose of the following analysis is to develop a method for determining vertical, horizontal, and torsional displacements of arbitrarily laminated, cantilevered composite box-beam under static, transverse loading. Small deflections are assumed and the differential equations of motion have been linearized for ease of calculation. The Smith and Chopra stiffness matrix is used in the equations of motion, and software was written to solve for the stiffness matrix elements. Comparisons are made with bending slope solutions from previously published results, and the presented analysis is compared to empirical results of a composite box-beam under tip loading. Finally, an example solution …

An Ameliorated Prediction Of The Empennage In-Flight Gust Loads For A General Aviation Aircraft, Philippe Marchand

Master's Theses - Daytona Beach

Airplanes often operate beyond their original design load profiles. Aviation opens so many new possibilities and wide variety of possible activities that it is hard for designers to foresee all loading spectra that the airplane structure will experience throughout its life. Nevertheless, the aircraft structures are required to be designed to failsafe or safe-life criteria to be certified by the FAA. AFS-120 provides a database of normal accelerations that can be used to derive airplane wing loads. ACE-100 describes an acceptable method for determining the fatigue life of an empennage based on the same normal acceleration data provided in AFS-120. …

Nonlinear Analysis Of Unsymmetric Laminates Under Cylindrical Bending, Eun Seon Park

Master's Theses - Daytona Beach

Nonlinear analysis of unsymmetric composite long, narrow laminates under cylindrical bending is studied. The nonlinear governing equations are obtained to analyze the cylindrical bending of arbitrary laminates. The von-Karman type geometrical nonlinearity is incorporated in the governing equation. The shear effect between lamina is further considered in the governing equation. The solution is obtained for different boundary conditions. The results of arbitrary angle-plies are discussed. Unidirectional prepreg graphite-epoxy is considered for numerical results.

The Static Thrust Characterization Of The Quatra Aerrow Q100xl Engine For Flight Performance Prediction Of The 1/3-Scaled Cessna 172p Model, Joon Fui Ho

Master's Theses - Daytona Beach

The purpose of this research is to predict the thrust as a function of forward flight velocity required for the one-third-scaled Cessna 172P. This model was designed to verify scaling laws. Therefore, it is important that it be aerodynamically scaled and that it have similar thrust characteristic as that of the full scale Cessna 172P. Several propellers and two Quatra Aerrow Q100XL two-cycle engines were acquired for this research project. Three propellers were selected to undergo a series of static thrust testing. The measured static thrust was then used to predict the flight performance of each tested propellers with the …

An Intermittent-Combustion General Aviation Aircraft Engine Exhaust Noise Prediction Algorithm, Hiroko Tada

Master's Theses - Daytona Beach

From an environmental point of view, the reduction of aircraft noise has become an important factor recently. There are two factors that make airplane noise: propeller noise and engine noise. This report puts emphasis on only the engine noise in order to begin understanding what airplane engine exhaust noise is. At first, the engine exhaust noise is comprehended using the Dobrzynski's engine noise theory. Next, a discussion about an Embry-Riddle Aeronautical University (ERAU) engine system, engine exhaust system configurations, and microphone setting standards that show the ERAU engine system exhaust noise data. Finally, an Intermittent-Combustion (IC) General Aviation (GA) aircraft …

Designed Reduction Of Radiated Noise Characteristics From Two-Bladed General Aviation Propellers, Chandra K. Stich

Master's Theses - Daytona Beach

In recent years increased public awareness has made the reduction of environmental noise pollution a top priority for the aviation industry. Utilizing current technology, this study examines the reduction of noise generated by two bladed general aviation propellers, through design. The Aircraft Noise Prediction Program - Propeller Analysis System (ANOPP-PAS) is used to predict the noise and performance characteristics for an industry typical reference propeller as well as for the final quiet and efficient design.

This investigation is based on the use of a 200 hp engine rotating a 76 inch propeller. Typically, such a propeller would be rotated at …

Optimization Of A Vortex Generator Configuration For A 1/4-Scale Piper Cherokee Wing, Kerri A. Raykowski

Master's Theses - Daytona Beach

Several sets of wind tunnel tests were performed to determine an optimum vortex generator configuration for a 1/4-scale model of the Piper Cherokee wing. Several variables were incorporated into this experiment in an effort to determine their influence on vortex generator performance enhancement (or degradation). Vane type vortex generators were used with 3 different leading edge sweeps: zero (rectangular planform), 20, and 45 degrees. Three different vortex generator heights were tested (0.05”, 0.1”, and 0.2”) to find the optimal vortex generator height relative to the local boundary layer thickness. The vortex generator angle of incidence relative to the freestream was …

Reduction Of Helmet Buffeting In Open Cockpit, Single Seat Race Cars, Mark Vallon

Master's Theses - Daytona Beach

At speeds approaching 240 mph, drivers of open cockpit race cars frequently experience large aerodynamic forces which act on the helmet. These forces, specifically the aerodynamic buffeting of the helmet, reach levels which are very fatiguing and distracting to the driver, and are therefore unacceptable. Little investigation has been done in this area, because normal wind tunnel tests do not isolate the helmet from the rest of the car. During this project, measurements of aerodynamic forces acting on a helmet inside a race car cockpit were made to determine the cause of the buffeting, and to determine possible improvements.

Tests …

Effect Of Multiple Range Rings Vs. A Single Range Ring On Pilot Perception Of Vertical Separation On A Cockpit Display Of Traffic Information, Daniel B. Rizzardi

Master's Theses - Daytona Beach

The purpose of this study was to determine the effectiveness of both a two and four mile range ring versus a single three mile range ring on pilot's perception of future vertical separation as viewed on a cockpit display of traffic information. The subjects consisted of 30 volunteer pilots from Embry-Riddle Aeronautical University and the surrounding Daytona Beach, Florida area.

The simulation of a cockpit display of traffic information was generated using SuperCard® Version 1.6 software and a Macintosh IIx® personal computer. Eighty unique scenarios were monitored by the pilots in which they determined, as early as possible, what the …

Classification Of In-Flight Fatigue Cracks In Aircraft Structures Using Acoustic Emission And Neural Networks, Christopher Lee Rovik

Master's Theses - Daytona Beach

The research encompassed within this paper deals with the analysis and classification of fatigue cracks in aircraft structures. The particular structure that was examined was the vertical tail section of a Cessna T-303 Crusader aircraft. The analysis was performed using the nondestructive evaluation technique known as acoustic emission (AE), as well as the artificial intelligence of neural networks. Data were taken in a controlled laboratory environment as well as in a flying testbed aboard the aircraft.

The first part of the research involved the analysis of a typical aircraft structure in a controlled laboratory environment. This support structure was fabricated …

Fatigue Life Prediction Of Edge-Welded Metal Bellows Using Neural Networks And Multiple Linear Regression, David L.W. Ballard

Master's Theses - Daytona Beach

Edge-welded metal bellows present an ongoing challenge: the prediction of an accurate cycle life. Current methods rely on physical leak detection to determine a bellow's cycle life to failure. It is known, however, that crack initiation begins many cycles before a leak path is present. Bellows manufacturers require a method for detection of fatigue cracks when they initiate but before they result in leak rates large enough to contaminate a process. Acoustic emission (AE) testing is one method which can meet this need and is a proven, reliable technique for detecting crack initiation and monitoring fatigue crack growth.

Four sets …

A Comparison Of Pseudo 3-Dimensional Collision Avoidance-Predictor Displays For Free Flight, Steve Kertesz Jr.

Master's Theses - Daytona Beach

This study was the second of two studies to evaluate the use of a pseudo three-dimensional display to present information about future possible conflicts. The purpose of this study was to evaluate variations of a cockpit screen display that transfers relevant data to the pilot in a manner which is easy to interpret and to facilitate the possible stressful situations that may be encountered due to the proposed free flight environment. In the first phase, three display concepts, using three different screen designs were compared. In this study, three different displays, all of which used using the space-time predictor concept …

In-Flight Fatigue Crack Monitoring Of An Aircraft Engine Cowling, Samuel Gordon Vaughn Iii

Master's Theses - Daytona Beach

This research investigates the feasibility of implementing an in-flight fatigue crack monitoring system in an airplane to identify fatigue crack growth. An acoustic emission data acquisition system coupled with a Kohonen self organizing map neural network were used to perform the analysis.

Fatigue cracking was responsible for ripping the top of a fuselage off an Aloha Airlines Boeing 737-200 as it carried passengers over the Pacific Ocean, killing some aboard. This tragedy is perhaps a precursor of problems to come, as our nation’s aircraft age. These planes experience fatigue as they perform their daily routine of ferrying passengers from location …

Chemical Kinetics And Heat Transfer In Polyurethane Foam And Resin Composites, Yumi Morisaki

Master's Theses - Daytona Beach

A development of the composite materials parts require knowledge of the theoretical model that describes the physics, the chemical kinetics, and the heat-transfer properties of the materials.

For this work, the chemical kinetics of the polyurethane foam and the fiberglass-reinforced resin is investigated individually. An adiabatic method, which is commonly used by many investigators, is used for the polyurethane foam, while an isothermal degree and the rate of cure relationship is applied for the resin. A heat transfer effect during the curing process of both polyurethane foam and the resin is also investigated. A common approximate method for the heat-conduction …

Three-Bladed Propeller Design For The Reduction Of General Aviation Radiated Noise Characteristics, Ronald W. Finn

Master's Theses - Daytona Beach

The purpose of this study was to design a quiet 3-Bladed propeller for general aviation aircraft. A combination of design technique and analytical predictions using the NASA Aircraft Noise Prediction Program - Propeller Analysis System (ANOPP-PAS) was used to achieve this goal. The propellers were designed for an engine power of 200 hp, a rotational speed of 2,400 RPM and a free-stream speed of 160 kts. A straight 76 in. diameter 2-bladed propeller was designed as a reference for the 64 in. diameter 3-bladed propeller. The ANOPP-PAS computer code was used for predicting the aerodynamic performance and radiated noise characteristics …

A Study Of The Volume Of Fluid Method For Moving Boundary Problems, Marianne Francois

Master's Theses - Daytona Beach

Moving boundary problems are often encountered in engineering and science. One of the methods to solve such problems numerically is the volume of fluid (VOF) method. The VOF method uses an additional field variable/to track the interface using the Eulerian fixed grid. In this work, the VOF method is combined with the Continuum surface force model. The governing flow equations for Newtonian fluids in incompressible flow in two dimensions are solved using the pressure-based algorithm. A linear interface reconstruction algorithm is developed and improved by interpolations. In order to validate the code, the problem of the convection of a two-fluid …

An Analysis Of Current Interruption Upon The Behavior Of Light Bulb Filament During Initial Aircraft Impact In Support Of Aircraft Accident Investigations, Daniel J. Larow

Master's Theses - Daytona Beach

The purpose of analyzing annunciator panels, warning, and indicator lamps is to determine the state ("on" or "off") of each light bulb immediately before the impact. Determination of the state of lamps may help investigators determine the probable cause of the accident. The information gained from the lamp's filaments may be used to infer the aircraft's operational parameters prior to impact and to a qualitative appreciation of the severity of the accident. It is generally agreed that upon impact the filament of an unlit bulb will fracture without deformation and the filament of a lit bulb will display plastic deformation …

Application Of Active Noise Control To Reduce Cabin Noise In Single Engine General Aviation Aircraft, Jeroen Hendrik Dolmans

Master's Theses - Daytona Beach

The application of active noise control to reduce cabin noise in single engine, general aviation aircraft is investigated through the use of the 'filtered x' least mean square algorithm and a simple acoustic feedforward method to generate a reference signal is tested. The system is designed to utilize one reference signal and up to two feedback signals and two audio speakers. The feedforward system consists of a microphone placed in close proximity to the front windshield and isolated from the cabin noise. Cabin noise and reference signals are recorded during flight in a Cessna 172 Skyhawk, a Piper Cherokee 140 …

Development And Initial Evaluation Of An Acoustic Apparatus Used For Testing Of Farfield Noise Emitted By A Propeller In A Short Duct, R. Duane Oleson

Master's Theses - Daytona Beach

The purpose of this thesis was to design, construct and evaluate an apparatus which was used for testing of acoustic emissions by a propeller in a short duct. An apparatus was designed based on a combination of acoustic principles and a desire to be able apply the knowledge gained to a practical application such as an ultralight aircraft in an effort to reduce the overall noise levels emitted. The apparatus consisted of a 35 horsepower ultralight engine, a four bladed ultralight propeller, and a duct constructed of a foam core covered with fiberglass. Initial evaluations compared noise levels from the …

The Design And Experimental Optimization Of A Wingtip Vortex Turbine For General Aviation Use, Andrew Roberts

Master's Theses - Daytona Beach

A wingtip vortex turbine (WVT) is an induced drag reduction device that straightens the vortex flow (reducing induced drag and wake turbulence) and also produces a thrust force component. The WVT also has the advantage of extracting the rotational energy of the vortex to turn a generator, which could be used to power onboard applications during normal or emergency flight operations. A 1/4-scale model of a thrust-producing WVT has been designed and tested in a wind tunnel for optimal drag reduction and power generation for general aviation aircraft — specifically, a Piper Cherokee — in both a stationary and a …

Cooperative Power-Limited Optimal Rendezvous Between Many Spacecraft, Virginie Guerre

Master's Theses - Daytona Beach

The minimum fuel rendezvous problem between several power-limited low-thrust spacecraft neighboring either a circular or an elliptic orbit is investigated. Both cooperative and non cooperative maneuvers are studied. The maximum principle of Pontryagin is applied to the optimal control rendezvous problem of several spacecraft. The gravitational field models investigated are the Clohessy-Wiltshire field and the inverse-square gravity field. Numerical solutions using a shooting method and the finite difference method are used in order to determine the trajectories of the spacecraft. Unlike previous investigations, this work is not restricted to a rendezvous of two spacecraft around a circular orbit, but a …

An Investigation Of The Hydrodynamic Effects Of Enteromorpha Clathrata Fouling On Hydrofoils, Brian J. Collino

Master's Theses - Daytona Beach

The purpose of this investigation was to determine the effects of biological fouling on hydrofoils. NACA 4412 and 4415 hydrofoil models with 6 inch chord and 8 inch span were used in this study. A water tunnel facility was designed and constructed to perform the tests, and the results were verified using computational fluid dynamic modeling. The CFD software package Fluent was used to create a two dimensional model of the water tunnel test section and hydrofoil. The model was meshed using a Laplacian grid smoothing technique that forced the structured grid lines to follow the same approximate contour as …

Burst Pressure Prediction Of Filament Wound Composite Pressure Vessels Using Acoustic Emission, Marcus Elwood Fisher

Master's Theses - Daytona Beach

This research demonstrates how acoustic emission (AE) data from flaw growth activity can be used to predict burst pressures in filament wound composite pressure vessels. Acoustic emission data were taken during hydroproof testing for a set of eleven ASTM standard 5.75 inch diameter fiberglass/epoxy bottles. Amplitude distributions were created using only the AE data up to 25% of the expected burst pressure to simulate low level proof loadings (thereby avoiding damage to the bottles). The bottles were tested at three different temperatures -- 32°F, 70°F, and 110°F - and hydroproofed using two different pressurization schemes and two transducer configurations. Moreover, …

Detection Of Fatigue Crack Growth In A Simulated Aircraft Fuselage, Michael Lee Marsden

Master's Theses - Daytona Beach

Acoustic emission (AE) nondestructive testing can detect fatigue cracks as they occur in complex structures. One use for AE has been in-flight detection of fatigue cracks in aircraft. The KC-135 aircraft were successfully monitored as early as 1979. The main problem with this and subsequent applications was an unfavorable signal to noise ratio, the key being to separate the small amplitude crack signals from the large amplitude ambient noise. This was accomplished here through the use of a Kohonen self-organizing map (SOM) neural network.

In order to simulate a fuselage undergoing fatigue, a pressure vessel was constructed from a 0.040 …