Aerospace Engineering Commons^™

Shock Tube Investigation Of Pressure And Ion Sensors Used In Pulse Detonation Engine Research, Robert J. Mcmillan

Theses and Dissertations

Shock tubes utilize a difference in pressures between gases separated by a diaphragm to create a shock wave when the diaphragm ruptures. By using sensors of known spacing, the speed of the wave can be determined. The AFIT 2-inch shock tube was reassembled and tested to ensure proper and safe operation. A high-speed data acquisition system was configured to take data at 2 MS/s. This research showed that the Mach number of the shock waves produced in this shock tube fall within 7% of theoretical values at speeds under Mach 3 and within 9% at higher speeds. The peak velocity …

An Assessment Of Modern Methods For Rotor Track And Balance, Michael J. Renzi

Theses and Dissertations

One routine maintenance item facing the helicopter industry today is the issue of rotor track and balance (RT&B). While the task of reducing vibrations is often overlooked as simply an unimportant maintenance concern, what should not be overlooked is the extensive amount of time and money committed by maintenance to smoothing an aircraft. If there were a way to make the process of rotor track and balance more efficient it would be a huge boost to the helicopter industry in both time and money. The first steps towards research into new and improved methods is to evaluate what is currently …

Isomer Heat Exchanger Combustor Replacement For A Supersonic Ramjet Powered Vehicle, Jonathan C. Cox

Theses and Dissertations

This study investigated the possibility of utilizing a Triggered Isomer Heat Exchanger (TIHE) within a ramjet engine to power a supersonic Conventional Air Launched Cruise Missile (CALCM). A computational ramjet engine was created using engine analysis software. This model was then run through a simulated cruise missile mission using AEDsys, a mission analysis and engine performance software suite. The replacement of the combustor with a TIHE led to an impressive range increase for the supersonic cruise missile.

Aeroelastic Analysis Of A Joined-Wing Sensorcraft, Jennifer J. Sitz

Theses and Dissertations

This study performed an aeroelastic analysis of a joined-wing SensorCraft. The analysis was completed using an aluminum structural model that was splined to an aerodynamic panel model. The force and pressure distributions were examined for the four aerodynamic panels: aft wing, fore wing, joint, and outboard tip. Both distributions provide the expected results (elliptical distribution), with the exception of the fore wing. The fore wing appears to be affected by interference with the joint. The use of control surfaces for lift and roll was analyzed. Control surfaces were effective throughout most of the flight profile, but may not be usable …

Neural Network Fatigue Life Prediction In 7075-T6 Aluminum From Acoustic Emission Data, Emeka Chigozie Ibekwe

Master's Theses - Daytona Beach

The objective of this research was to classify acoustic emission (AE) -data associated with fatigue cracks in aluminum fatigue specimens and to use early cycle life AE data to predict failure in such members. An AE data acquisition system coupled with a Kohonen self organizing map and a back propagation neural network were used to perform the analysis. AE waveforms were recorded during fatigue cycling of twenty-four notched 7075-T6 aluminum specimens using broad-band piezoelectric transducers. A Kohonen self organizing map was used to classify the AE flaw growth signals. The signals were classified into three categories based on their AE …

Solution Of Multi-Species Real Gas Flows With Electric Arc And Wall Ablation, Alexandre Martin, Marcelo Reggio, Jean-Yves Trépanier

Alexandre Martin

Nozzle ablation caused by high temperature electric arc is a physical phenomenon commonly found in high voltage electrical devices. In circuit breakers, for example, the strong ablation of the PTFE nozzle wall results in the creation of new species, which implies various chemical reactions. For the simulation of these phenomena, a bi-dimensional axisymmetric Euler equations model for multi-species flow has been developed. To solve the governing equations, a finite volume method based on Roe’s flux splitting scheme [11] has been established. The proposed scheme approaches the mean-values used in Roe’s matrix in a new way. To take into account the …

H-53e Super Stallion/Sea Dragon Auxiliary Power Plant Power Survey, Patrick Joseph Twomey

Masters Theses

This research has provided possible explanations to failures experienced in the P-7-2 Auxiliary Power Plant reduction gearbox as installed on the CH-53E Super Stallion and MH-53E Sea Dragon helicopters. Ground testing with the rotors static was conducted during two separate phases from March 1995 to December 1995. Reduction gearbox loading was measured, resulting in the identification of several detrimental over and transient loads. Loading reduction techniques are investigated, discussed, and/or evaluated for U.S. Navy and U.S. Marine Corps fleet introduction viability.

Testing Near Airspeed Limits During Safe Separation Flight Test, Peter J. Walczak

Masters Theses

Although all flight tests possess their own inherent risks, safe store separation tests, especially those targeting release conditions at or near maximum sanctioned clearance limits, add more hazards to an already bloated list of obstacles. Since the success of most modern flight test programs is measured in terms of cost, schedule, and performance, an unsuccessful test flight can add tens of thousands of dollars and months to an already beleaguered program. With ever-increasing flight hour costs and dwindling budgets, reducing or eliminating unnecessary or unsuccessful sorties is essential. The trick, then, is to fly to achieve desired test conditions, yet …

The Need For Accelerated Integration Of The Multifunctional Information Distribution System In The Fa-18c Hornet, William S. Koyama

Masters Theses

The FA-18 Hornet is a fourth-generation, supersonic, multi-role aircraft designed and built by the Boeing Aircraft Company, primarily for use as a single-seat US Navy and Marine Corps carrier-based strike/fighter. The Hornet has also been successful in the dual seat variant as both a trainer, and as a land-based aircraft for the Marines. All A through D variants have been marketed internationally as well. While the newer “E” and “F” variants are significantly different from the A through D variants in size and range and endurance capabilities, the avionics suites and capabilities are nearly identical. Except where noted, discussions of …

Proposed Design For Ea-6b Icap Iii Weapon-System Alert Display, Andre Laurence Mercier

Masters Theses

The EA-6B Prowler electronic warfare aircraft is undergoing a major weapon system improvement referred to as Improved Capabilities Three (ICAP III). The ICAP III upgrade presents an opportunity to improve the existing aircraft system for alerting the crew of potential weapon system problems.

This thesis provides a recommended design for display of weapon-system alerts in production Lot 1 configured EA-6B ICAP III aircraft. Human factors engineering methods, the ICAP III system performance specification and the author’s experience employing electronic warfare weapon systems were used to define required alerts. These tools along with human factors engineering research and software best practice …

F/A-18a-D Flight Control Computer Ofp Versions 10.6.1 And 10.7 Developmental Flight Testing: Out-Of-Controlled Flight Test Program Yields Reduced Falling Leaf Departure Susceptibility And Enhanced Aircraft Maneuverability, Eric John Mitchell

Masters Theses

This thesis analyzes the recent Version 10.7 Operational Flight Program (v10.7 OFP) Flight Control System upgrade to the F/A-18A-D (legacy) Hornet fighter aircraft. This developmental program endeavored to improve high angle-of-attack (AOA) maneuverability while vastly reducing the aircraft’s susceptibility to sustained out-of- controlled flight events.

Although the original F/A-18 Hornet, designated F/A-18A through F/A-18D, has been acclaimed for its departure resistance as well as its exceptional maneuverability as a fighter aircraft, the model, in actuality, has suffered from significant losses due to out-of- controlled flight (OCF) mishaps. Since its development in the early 1980s, eighteen Hornets have been lost to …

Incorporating Practical Experience With Aeronautical Design Standard 33 In The United States Naval Test Pilot School Rotary Wing Curriculum, Jeffrey Scott Dodge

Masters Theses

In the last decade, the world of helicopter testing has been significantly changed by the research involved in creating the latest military design specification named Army Design Specification 33, or ADS-33. ADS-33 has moved away from the use of traditional time-based methods of examining a helicopter’s response to control inputs to a method of comparing a helicopter’s response to the frequency of control input. ADS-33 also incorporates stylized but repeatable Mission Task Elements as a replacement for general mission-representative maneuvers. The research community has embraced this new theory and many test and research programs make use of ADS-33 methodology.

As …

A Study Of A Skirtless Hovercraft Design, Edward A. Kelleher

Theses and Dissertations

Initial study into three possible skirtless hovercraft designs. The designs utilize Coanda nozzles and a Coanda wing surface to generate lift and create a pressure cushion below the craft. The pressure cushion is to be maintained by an air curtain created by flow spill from the Coanda wing surface. Three proposed skirtless hovercraft designs were analyzed via computational fluid dynamics to ascertain their lift generation capabilities. The three designs were adaptations from William Walter's hybricraft primer and his patent for a fan driven lift generation device. Each design featured Coanda nozzles, or nozzles that utilize the Coanda effect, to redirect …

Use Of Commercial Off The Shelf Gps Technology To Solve Guidance Problems With The Improved Tactical Air Launched Decoy (Itald), Scott Kenneth Toppel

Masters Theses

As the capabilities of threat surface-to-air missile systems increased, the US Navy looked to improve upon the performance of the Tactical Air Launched Decoy (TALD), an air launched glider vehicle with switchblade wings designed to resemble attacking aircraft to confuse and saturate enemy air defenses. In the early 1990’s the contractor proposed the Improved Tactical Air Launched Decoy (ITALD), a turbo jet powered air-launched vehicle which tripled the existing range and added a radar altimeter to simulate low level attacks.

In 1998, after several design iterations, the Naval Air Warfare Center at Point Mugu tested the ITALD for suitability in …

Cfd Modeling Of Dynamic Inlet Flow Distortion Generation, Keith Patrick Savage

Masters Theses

Integrating a jet engine into an airframe involves many design and testing steps. The development of high performance fighter aircraft has added new requirements to this process. Ground test facilities are used to simulate the effect of inlet shape on the performance of an engine for cruise flight or other fixed conditions. While a static simulation of the inlet shape is adequate for most circumstance, military fighter craft are highly maneuverable, altering the inlet airflow intensely and briefly. These transient distortions can have a significant impact on performance as well as having the potential of causing structural problems. In addition …

Unique Aspects Of Unmanned Aerial Vehicle Testing, Mark David Lower

Masters Theses

The purpose of this paper is to examine the applicability of established manned aircraft test techniques and processes to the testing of Unmanned Aerial Vehicles (UAVs). While the paper is largely focused on the Naval Aviation perspective, input from several joint programs as well as some Air Force and Army testing is included. In addition, although handled differently, the testing of the Tomahawk Cruise Missile is also considered. Processes associated with test planning, risk mitigation and airworthiness are considered in some detail. Much of this document is drawn from UAV flight test experience compiled in a draft Advisory Group for …

Conceptual Design Of A Lunar Shuttle Transport Vehicle, Matthew David Finney

Masters Theses

In 1961 the former Soviet Union successfully launched the first human into space marking the beginning of the “Space Race” with the United States. Forty years later, the United States and Russia are working together in support of the International Space Station (ISS). The US Space Shuttle fleet and Russian Soyuz capsule and rockets are being used to replenish the ISS. In light of the latest shuttle accident and aging systems, NASA has been pursing alternatives to replace the shuttle fleet.

This study is a conceptual design of a spacecraft designed to meet the following requirements: 1. Transport a crew …

Women In Aviation, Kari Anne Sparks-Webb

Undergraduate Honors Capstone Projects

My goal during my enrollment in the USU Professional Pilot Program is to further the advancement of women in the aviation industry and increase the number of women in the flight program. So, when it came time to choose my senior project there was no better choice for me than to exhibit at the Women in Aviation Convention. It would be a huge step for the school and a great opportunity for me and other students in the program.

Assessment Of The Ah-64d Longbow Apache’S Handling Qualities For Instrument Meteorological Conditions/Instrument Flight Rules Flight, Michael J. Meely

Masters Theses

An assessment of the handling of the AH-64D for flight in IMC and under IFR was conducted. Testing was performed in the configurations listed in table 1 and under the conditions presented in tables 3 and 4. All test objectives were met. IMC mission maneuvers with all systems working resulted in satisfactory handling qualities with no excessive compensation required from the pilot (altitude and attitude holds ON). However, as the aircraft systems were progressively degraded the workload for the evaluating pilot increased significantly. The high workload coupled with the absence of a vertical speed indicator (VSI) and torque indication during …

The Investigation Of A Tin Oxide-Based Mems Sensor For Measurement Of Nitrogen Oxides In Aircraft Engine Exhaust, Lisa N. Urman

Masters Theses

An investigation was conducted of the performance of a tin oxide-based, MicroElectro Mechanical Sensor for making measurements of NO_X levels on gas turbine engine exhaust. This sensor was provided by Makel Engineering, Inc., as a prototype device for evaluation. In this thesis, the MEMS device is described together with its supporting equipment. Tests, and calibrations were performed and evaluations made on the MEMS sensor, and are discussed in three parts: laboratory calibration and evaluation, off-engine installation and performance, and on-engine instillation and performance.

The MEMS device was first tested in a laboratory environment where the temperature and pressure of …

High Resolution Turbulence Treatment Of F/A-18 Tail Buffet, Scott A. Morton, Russell M. Cummings, Denis B. Kholodar

Aerospace Engineering

Unsteady tail loads of the F/A-18 are computed using various turbulence models at an angle of attack consistent with buffet induced by leading-edge extension vortex breakdown. Comparison of these industry standard turbulence models with the Detached Eddy Simulation (DES) hybrid RANS-LES approach reveals the inadequacies of RANS methods and the ability of DES to reproduce the observed unsteadiness at these conditions. Computed vortex breakdown position and frequencies of the DES method are shown to be accurate by comparison to flight test and experimental results. Finally, comparison of the DES unsteady tail pressures with flight-test tail pressures reveal the ability of …

Flightlines, Vol. 11, No. 2, Jeffrey A. Johnson

Flightlines Newsletter

No abstract provided.

Ultimate Strength Prediction In Fiberglass/Epoxy Beams Subjected To Three-Point Bending Using Acoustic Emission And Neural Networks, Michele D. Dorfinan

Master's Theses - Daytona Beach

The research presented herein demonstrates the feasibility of predicting ultimate strengths in composite beams subjected to 3-point bending using a neural network analysis of acoustic emission (AE) amplitude distribution data. Fifteen unidirectional fiberglass/epoxy beams were loaded to failure in a 3-point bend test fixture in an MTS load frame. Acoustic emission data were recorded from the onset of loading until failure. After acquisition, the acoustic emission data were filtered to include only data acquired up to 80 percent of the average ultimate load.

A backpropagation neural network was constructed to predict the ultimate failure load using these AE amplitude distribution …

Improving The Capability Of Preliminary Aircraft Design Methodology By Incorporating Numerical Methods Into Segments Of A Proven Statistical Method, Igor Lebovic

Master's Theses - Daytona Beach

The purpose of this study was to identify any potential limitations of Roskam’s statistical aircraft flight performance estimation method, and to provide processes capable of improving those limitations. This project was conducted in collaboration with Diamond Aircraft Industries, and as any other general aviation manufacturer with limited time, manpower, and financial resources, Diamond wants the new process to be time and cost-effective. Presented in this study is a computational alternative that combines the speed and accuracy of low-order panel methods with the fully-coupled viscous/inviscid interaction method from the ISES code that was developed by Drela and Giles. Its benefit is …

An Analysis Of Intention Formation As A Function Of Prospective Memory In Air Traffic Controllers, Jennifer Nagle

Master's Theses - Daytona Beach

Prospective memory, or memory for future intents, is an important part of everyone's daily life. Air traffic controllers whose jobs are based in an environment that taxes their memory resources for extended periods of time rely on this type of memory. Controllers objectives often change based on incoming information and the amount of traffic they are controlling. It is important to investigate how controllers form intentions for future events, what processes facilitate retrieval of this information, and establish what influence experience may have. This study proposes to assess controllers in an air traffic scenario by employing a cognitive task analysis …

Subcooled Pool Boiling Heat Transfer Using R113 On Flat Surface, Kamleshkumar J. Suthar

Masters Theses

Pool boiling experiment was conducted to investigate the effect of subcooling on boiling of R-113 using 25mm effective dia. flat surface copper heater. Pool boiling heat transfer measurements were taken for wide temperature range of 5 - 39^o C subcooling and investigated thoroughly. Variation in value of wall superheat of incipience boiling, from 27 to 34^o C and 7 to 11^o C temperature excursion observed. Noticeable effect of subcooling on boiling heat transfer is observed. Degree of subcooling was maintained constant by regulating pressure and keeping constant fluid temperature for each test run. Tests were conducted by …

The Airline Quality Rating 2004, Brent D. Bowen, Dean Headley, Uno Aviation Institute

Faculty Books and Monographs

UNOAI Report 04-1

The Airline Quality Rating (AQR) was developed and first announced in early 1991 as an objective method of comparing airline quality on combined multiple performance criteria. This current report, the Airline Quality Rating 2004, reflects monthly Airline Quality Rating scores for 2003. AQR scores far the calendar year 2003 are based on 15 elements in four major areas that focus on airline performance aspects important to air travel consumers.

The Airline Quality Rating 2004 is a summary of month-by-month quality ratings for U.S. airlines that have at least 1% of domestic passenger volume during 2003. Using the …

Prediction Of Rigid Body Aircraft Acceleration Response Due To Atmospheric Disturbances, Billy Keith Buck

Mechanical & Aerospace Engineering Theses & Dissertations

Methodology to predict aircraft transient motion resulting from flight within an unsteady atmospheric environment, coupled with validation using flight test data is proposed. A family of five linear dynamic models is developed for describing the normal acceleration throughout an aircraft cabin due to vertical gust excitation. The five models successively build upon each other by incorporating higher fidelity gust penetration effects while simultaneously maintaining a unified modeling framework. Six wind fields reconstructed from flight test data are used to excite the vehicle models. Simulation responses are compared with forward, center, and aft accelerometer response data recorded during the test. Each …

Data Smoothing And Interpolation Using Eighth-Order Algebraic Splines, Daniel J. Simon

Electrical and Computer Engineering Faculty Publications

A new type of algebraic spline is used to derive a filter for smoothing or interpolating discrete data points. The spline is dependent on control parameters that specify the relative importance of data fitting and the derivatives of the spline. A general spline of arbitrary order is first formulated using matrix equations. We then focus on eighth-order splines because of the continuity of their first three derivatives (desirable for motor and robotics applications). The spline's matrix equations are rewritten to give a recursive filter that can be implemented in real time for lengthy data sequences. The filter is lowpass with …

Coplanar Air Launch With Gravity-Turn Launch Trajectories, David W. Callaway

Theses and Dissertations

The purpose of this study was to determine the feasibility of launching a vehicle based on the Boeing AirLaunch System in a coplanar, direct to rendezvous trajectory with gravity-turn. The focus of the research was to model the launch trajectory and determine the ability to reach different coplanar orbits. The launch trajectory was modeled using two-dimensional equations of motion and a boundary value problem was posed and solved for the gravity-turn trajectory. Trajectories were then created in an attempt to reach different altitudes through coasting and transfer orbits. Finally a specific orbital altitude was chosen and the trajectories were analyzed …