Engineering Commons^™

Evaluating Launch Vehicle / Reentry Vehicle (Lv/Rv) Separation Concepts, Zheng Tao, Ganghuai Wang, Tudor Masek, Thomas J. St. Clair

Space Traffic Management Conference

Launch Vehicle/Reentry Vehicle (LV/RV) operations are expected to increase across the National Airspace System (NAS) as their reliability and availability improve. LV/RV designs and the industry landscape have vastly changed since the 1960’s, and the Federal Aviation Administration’s (FAA) methods for handling these operations need to evolve to support the expected growth. Currently, large amounts of airspace are segregated for every LV/RV operation. This increases costs for NAS users and may limit LV/RV opportunities. The FAA’s NextGen office recently proposed two more efficient separation concepts for LV/RV operations called Space Transition Corridors, and Four-Dimensional Trajectory Deconfliction. Prior safety research for …

Lumped Parameter Model For A Self Powered Fontan Palliation Of The Hypoplastic Left Heart Syndrome, Jang Ho Park

Doctoral Dissertations and Master's Theses

Out of all newborn infants with congenital heart disease (CHD), 8% have a single functioning ventricle. The Fontan surgical procedure, where the superior and inferior venous returns are connected directly to the pulmonary arteries to allow the single functioning ventricle to perfuse the systemic circulation, has been around for decades, yet the patients who undergo this operation suffer from chronic illnesses and their survivability is less than 50% by adulthood [1-10]. Some suggest that the Fontan operation can be improved by implanting a synthetic pump. However, synthetic pumps also present some complications due to mechanical failure, risk of stroke, and …

Development And Prototype Validation Of An Additive Manufactured Cubesat Propulsion Tank, Geovanni A. Solorzano

Doctoral Dissertations and Master's Theses

The purpose of this study is to determine if a cubesat propellant tank using the additive manufacturing technology of direct metal laser sintering meets the requirements, and material properties of a conventionally manufactured tank. Additionally, to see if additive manufactured parts are a viable option to be used in cubesat applications. This was accomplished by designing a model which will be used by the ARAPAIMA cubesat that meets all the Air Force's University Nanosatellite Program (UNP), NASA's and Department of Defense's requirements for pressurized vessels and material properties. A finite element analysis study was conducted to determine where and when …

An Experimental Method To Calculate Coefficient Of Friction In Mecanum Wheel Rollers And Cost Analysis Using Dfma Techniques, Nishant Sonawane

Doctoral Dissertations and Master's Theses

Mecanum wheel is a special kind of omni-directional wheel which is designed for robot vehicles. The purpose of this thesis is to work on geometry and working of Mecanum wheel rollers and to conduct experiments on these rollers to find its values of coefficient of friction in different conditions. This thesis also includes the work conducted to formulate the equations which can be used to find different parameters of roller for its motion, kinematics, rolling, friction and overall impact with respect to the working of a robot. The work is tested in experiments and the values are compared with previous …

Identifying Secondary Crashes By Using Geographic Information System (Gis) And Determining The Secondary Crashes Characteristics, Yuan Tian

Doctoral Dissertations and Master's Theses

As the nation’s transportation infrastructure expands, traffic incidents led to more than 25% of traffic congestion in the United States (FHWA, 2014). The risk of the occurrence of secondary crashes can be six times higher in the presence of a primary crash than that at a normal traffic condition (Yang et al., 2013 and Tedesco, 1994). The purpose of this study is 1) to develop a method to identify the secondary crashes with the primary incidents in Geographic Information Systems (GIS) under different spatial-temporal criteria, and 2) to determine the impacts of spatial-temporal criteria on the secondary crash characteristics in …

Enhancing Quality Assurance Using Virtual Design Engineering: Case Study Of Space Shuttle Challenger, Kouroush Jenab, Scot Paterson

International Journal of Aviation, Aeronautics, and Aerospace

Virtual Design Engineering is an emerging method of increasing quality of systems. Including Virtual Design as a part of the traditional established Failure Mode, Effects, and Criticality Analysis process greatly enhances hazard and risk analysis while reducing overall costs. In this study these enhancements are explored and expanded upon to discover how overall system quality could be increased and all stakeholders could more accurately understand the hazards involved. Stakeholder misunderstanding or misapplication of hazards is of great importance to complex systems. An illustrative example of how these factors could have changed the outcome of a real-world engineering failure is provided.

Examining Unmanned Aerial System Threats & Defenses: A Conceptual Analysis, Ryan J. Wallace, Jon M. Loffi

International Journal of Aviation, Aeronautics, and Aerospace

The integration of unmanned aerial systems (UAS) into the already complex global aviation system presents new and unique hazards. While many studies have addressed the potential safety concerns of UAS integration, little research has been dedicated to the potential security implications. This study sought to identify potential uses and adaptations of civil UAS systems as weapons of terrorism or crime and potential UAS defenses. Researchers examined 68 academic studies, unclassified government reports, and news articles using Conceptual Analysis to systematically capture and categorize various threats. Using the collected data, researchers developed a UAS threat model for categorically evaluating potential threats. …

A Sliding Mode Lco Regulation Strategy For Dual-Parallel Underactuated Uav Systems Using Synthetic Jet Actuators, N. Ramos-Pedroza, W. Mackunis, M. Reyhanoglu

Publications

"A sliding mode control- (SMC-) based limit cycle oscillation (LCO) regulation method is presented, which achieves asymptotic LCO suppression for UAVs using synthetic jet actuators (SJAs). With a focus on applications involving small UAVs with limited onboard computational resources, the controller is designed with a simplistic structure, requiring no adaptive laws, function approximators, or complex calculations in the control loop. The control law is rigorously proven to achieve asymptotic regulation of both pitching and plunging displacements for a class of systems in a dual-parallel underactuated form, where a single scalar control signal simultaneously affects two states. Since dual-parallel underactuated systems …

Pattern Formation Of Elastic Waves And Energy Localization Due To Elastic Gratings, A. Berezovski, J. Engelbrecht, Mihhail Berezovski

Publications

Elastic wave propagation through diffraction gratings is studied numerically in the plane strain setting. The interaction of the waves with periodically ordered elastic inclusions leads to a self-imaging Talbot effect for the wavelength equal or close to the grating size. The energy localization is observed at the vicinity of inclusions in the case of elastic gratings. Such a localization is absent in the case of rigid gratings.

How Trust In Commercial Airline Pilots Is Affected By Their Perceived Sociability: A Mediation Analysis, Stephen Rice, Scott R. Winter, Russell Tokarski

Publications

Sociability relates to one’s preference to interact with others or remain alone. The current study sought to determine how a pilot’s perceived sociability would relate to consumers’ trust ratings in their pilot using participants from India and the United States. Consumers were presented with one of two scenarios. In the control condition, the pilot was described as sociable, while in the other, the pilot was presented as unsociable. Participants were then asked to rate their trust in the pilot based off of these cues. In general, participants indicated that the pilot who was perceived as unsociable was less trusting compared …

Factors Affecting Dimensional Precision Of Consumer 3d Printing, David D. Hernandez

International Journal of Aviation, Aeronautics, and Aerospace

This paper investigates the factors affecting dimensional precision of consumer-grade 3D printing, attempting to isolate and mitigate sources of error. The focus is on creating engineering prototypes of, tooling for, or finalized instances of mechanical devices. A specific fused deposition modeling printer – the Ultimaker 2 – is analyzed in terms of meeting precise physical dimensions, consistent shapes, and predictable surface finish. Extensive trial and error resulted in removal of several sources of bias, with square test articles exhibiting a lower-than-anticipated mean percentage error of -0.387% (SD = 0.559), a value comparable to other modern manufacturing techniques. A full …

Amelia Earhart - A Study In Courage, Daring And Foolhardiness, Gene Tissot

ERAU Prescott Aviation History Program

Amelia Earhart, disappeared while almost completing an around-the-world flight. This was just one of her many daring adventures. Hear the story of her relatively short, but dynamic aviation career from Gene Tissot, whose father was Amelia’s mechanic during her Hawaii to California flight in 1935. Admiral Tissot knows the pacific well as a decorated combat pilot in Korea & Vietnam. He became the third naval aviator to achieve 1000 arrested carrier landings, without an accident over 20 years, flying 11 different aircraft types.

Causes And Trends In Maintenance-Related Accidents In Faa-Certified Single Engine Piston Aircraft, Douglas Boyd, Alan Stolzer

Publications

The accident rate for general aviation remains high. While most general aviation accident studies have been pilot-focused, there is little research on the involvement of aircraft maintenance errors. We undertook a study to answer this question.

The Microsoft Access database was queried for accidents occurring between 1989 and 2013 involving single engine piston airplanes operating under 14CFR Part 91. Pearson Chi-Square, Fisher’s Exact Test, and Poisson probability were used in statistical analyses.

The rate of maintenance-related general aviation accidents was 4.3 per million flight hours for the 1989–1993 period and remained unchanged for the most recent period (2009–2013). Maintenance errors …

Book Review: High G Flight - Physiological Effects And Countermeasures, Stefan Kleinke

International Journal of Aviation, Aeronautics, and Aerospace

This review provides insight on the content and a review of the quality of the recent release of High G Flight - Physiological Effects and Countermeasures from Ashgate Publications.

This review does not reflect the views of IJAAA or ERAU. This work was not peer reviewed.

High G Flight - Physiological Effects and Countermeasures

Aviation Bird Hazard In Nexrad Dual Polarization Weather Radar Confirmed By Visual Observations, Bradley M. Muller, Frederick R. Mosher, Christopher G. Herbster, Anthony T. Brickhouse

International Journal of Aviation, Aeronautics, and Aerospace

Birds represent a significant hazard to flying aircraft as illustrated by the “Miracle on the Hudson” encounter in 2009 between U.S. Airways Flight 1549 and a flock of Canada Geese, forcing the flight to ditch in the river. Birds are common in the skies over Florida during the spring migration season, and often appear in the National Weather Service’s (NWS) NEXRAD weather radar imagery as an easily recognizable signature known as a “roost ring.” This paper presents a NEXRAD roost ring case in central Florida in a rare instance where the signatures were confirmed by visual observations of the birds. …

Global Optimized Isothermal And Nonlinear Models Of Earth’S Standard Atmosphere, Nihad E. Daidzic, Ph.D.,

International Journal of Aviation, Aeronautics, and Aerospace

Both, a global isothermal temperature model and a nonlinear quadratic temperature model of the ISA was developed and presented here. Constrained optimization techniques in conjunction with the least-square-root approximations were used to design best-fit isothermal models for ISA pressure and density changes up to 47 geopotential km for NLPAM, and 86 orthometric km for ISOAM respectively. The mass of the dry atmosphere and the relevant fractional-mass scale heights have been computed utilizing the very accurate eight-point Gauss-Legendre numerical quadrature for both ISOAM and NLPAM. Both, the ISOAM and the NLPAM represent viable alternatives to ISA in many practical applications and …

Examining How Breakdowns In Pilot Monitoring Of The Aircraft Flight Path, Robert Sumwalt, David Cross, Dennis Lessard

International Journal of Aviation, Aeronautics, and Aerospace

Aircraft accident and incident data reveal that serious safety consequences can arise when flight crewmembers fail to properly monitor the aircraft flight path. This research study reviewed human factors literature to better understand why pilots fail to properly monitor, and analyzed accident and incident data. Recommendations for improving monitoring performance were formulated, which may be useful to air carriers in implementing a new Federal Aviation Administration requirement that calls for specific training in monitoring.

Random Actuation Pattern Optimization By Genetic Algorithm For Ultrasonic Structural Health Monitoring Of Plates, Pierrot R. Derjany

Doctoral Dissertations and Master's Theses

The objective of this research is to investigate an optimized two-dimensional random pattern of uniformly excited points using the Genetic Algorithm (GA) technique for structural health monitoring. The point excitations generate ultrasonic waves in both isotropic and anisotropic materials that can be effective in diagnosing structural defects. The formed ultrasonic waves can constructively interfere and send out an intense wave beam to a predetermined target. The constructed wave beams can be steered to different directions with variable target distances. In the GA, the cost function is constructed to reduce main lobe beamwidth, eliminate grating lobes and suppress sidelobes’ levels. Mathematical …

Similarity Analysis Of A Swirling Counter-Flow, Jitesh Rane

Doctoral Dissertations and Master's Theses

Swirling counter-flows are used in numerous engineering applications, like combustion, heat exchangers, cyclonic separation and mixing, etc. These swirling counter-flows produce complex flow fields. It is important to study these types of flows in order to use them properly in many applications.

The present work provides insight into the flowfield inside a swirling counter-flow when the fluid is injected tangentially in a cylindrical container. A semi-analytical solution is developed by starting with the full Navier-Stokes equation and using a similarity analysis. A decaying swirl along the axis of the cylinder is assumed, which reduces the Navier-Stokes equations to first order …

How Do Depression Medications Taken By Pilots Affect Passengers' Willingness To Fly? A Mediation Analysis, Stephen Rice, Scott R. Winter, Keegan Kraemer, Rian Mehta, Korhan Oyman

Publications

The mental health of airline pilots has been a concern for decades. In 2010, the United States Federal Aviation Administration began allowing four types of selective serotonin reuptake inhibitors (SSRIs) to be used by pilots suffering from depression. After a procedural wait period, pilots may be awarded a special issuance of their medical certificates to maintain flight currency. Missing from the literature was any research on consumer’s perceptions of pilots taking antidepressants, along with some other approved medications. Therefore, the purpose of the current study was to examine consumer’s willingness to fly once told that the pilot of their hypothetical …

A Patient-Specific Model Of The Biomechanics Of Hip Reduction For Neonatal Developmental Dysplasia Of The Hip: Investigation Of Strategies For Low To Severe Grades Of Developmental Dysplasia Of The Hip, Victor Huayamave, Christopher Rose, Sheila Serra, Brendan Jones, Eduardo Divo, Faissal Moslehy, Alain J. Kassab, Charles T. Price

Publications

A physics-based computational model of neonatal Developmental Dysplasia of the Hip (DDH) following treatment with the Pavlik Harness (PV) was developed to obtain muscle force contribution in order to elucidate biomechanical factors influencing the reduction of dislocated hips. Clinical observation suggests that reduction occurs in deep sleep involving passive muscle action. Consequently, a set of five (5) adductor muscles were identified as mediators of reduction using the PV. A Fung/Hill-type model was used to characterize muscle response. Four grades (1–4) of dislocation were considered, with one (1) being a low subluxation and four (4) a severe dislocation. A three-dimensional model …

Exploring New Lagrangian Cyclers To Enhance Science: Communications With Cubesat Technology, Pedro P. Llanos, Abdiel Santos Galindo, John Ford

Publications

This paper discusses the opportunities that abound by using the CubeSat technology to travel to and communicate with the International Space Station, explore space, monitor space weather, monitor space debris and perhaps travel to Mars.

Bio-Fuel Alternatives In South African Airways (Saa) Operations - Is It An Effective Response To Vulnerability Over Carbon Taxes And Penalty?, Daniel Kwasi Adjekum

International Journal of Aviation, Aeronautics, and Aerospace

The paper did a comparative analysis of the carbon emission and European Union Emission Trading Surcharges (EU ETS) of South African Airways (SAA) current fleet that used aviation jet A1 fuel and the same fleet if it had used a 25% bio-fuel ‘drop in’ for the European routes within the first quarter of the 2014 flying year (FY 14). Operational data in terms of the flight scheduled, aircraft type, total time enroute, route stage length, passenger estimates were obtained through SAA’s flight operations website. An independent t–test was conducted to compare means of the emissions. The mean carbon dioxide …

Should Charity Air Medical Organizations Require Commercial Certification Of Their Pilots?, Douglas Boyd, Charles Peters

Publications

Fixed-wing medical transportation crashes operating under 14CFRPart 91 show higher fatal outcomes than non-medical Part 91 flights. Advanced certification may translate into increased safety; yet we know of no charity aeromedical transportation requiring such certification. Herein, in a retrospective study, we determined (a) whether commercial certification is associated with a reduced fatality rate compared with the less stringent private pilot certificate and (b) accident causes.

Design And Validation Of Hardware-In-The-Loop Testbed For Proximity Operations Payloads, Kristia K. Harris

Doctoral Dissertations and Master's Theses

The research presented here is a new testbed design for CubeSat and payload testing and development. This research demonstrates a low-cost, hardware-in-the-loop testing apparatus for use with university CubeSat programs for testing throughout the different levels of the development process. The average university CubeSat program undergoes very little hardware-in-the-loop testing. Most of the focus is the targeted towards performance testing and environmental testing which occur after completion the development process. This research shows that, for minimal schedule and cost impact, testing can occur early in the development process. The testbed presented here demonstrates suitable accuracy to be used for advanced …

Slipstream Measurements Of Small-Scale Propellers At Low Reynolds Numbers, Robert W. Deters, Gavin K. Ananda, Michael S. Selig

Publications

The continuing growth in the use of small UAVs has required the need to more fully understand the propellers that power them. Part of this understanding is the behavior of the propeller slipstream. Using a 7-hole probe, the slipstreams of several small-scale propellers (diameters of 4.2, 5, and 9 in) were measured in both static (V∞ = 0) and advancing-flow (V∞ > 0) conditions at several locations downstream. For static conditions, as the slipstream expanded downstream, the maximum values of the axial and swirl velocities decreased. The general shape of the static slipstream was also found to be nearly the same …

The Epa P3 Program: An Opportunity For Growing Student Entrepreneurs, Marc Compere, Yan Tang, Yung Wong

Publications

In this paper we will share our experiences of fostering entrepreneurial spirit through projects funded by EPA (Environmental Protection Agency) P3 (People, Prosperity, and the Planet) Program which hosts the P3 collegiate competition for designing solutions for a sustainable future. Since 2012, we have integrated the P3 competition with the capstone design course of Clean Energy Systems track in mechanical engineering as an effective educational vehicle for introducing the concept of sustainable design. Since the competition focuses on designs which have values of real world application, it is also a great opportunity to create entrepreneurial spirit. We have successfully turned …

Direct Atmospheric Evidence For The Irreversible Formation Of Aqueous Secondary Organic Aerosol, Marwa M. El-Sayed, Yingqing Wang, Christopher J. Hennigan

Publications

The reversible nature of aqueous secondary organic aerosol (aqSOA) formation was characterized for the first time through direct atmospheric measurements. Water-soluble organic carbon in the gas and particle phases (WSOCg and WSOCp) was measured simultaneously to quantify aqSOA formation in Baltimore, Maryland. During the nighttime, aqSOA formation was evident as WSOCg increasingly partitioned to the particle phase with increasing relative humidity (RH). To characterize the reversible/irreversible nature of this aqSOA, the WSOCp measurement was alternated through an unperturbed ambient channel and through a “dried” channel maintained at ~40% RH (with 7 s residence time) to mimic the natural drying particles …

Influencing Factors For Use Of Unmanned Aerial Systems In Support Of Aviation Accident And Emergency Response, Brent Terwilliger, Dennis Vincenzi, David Ison, Kenneth Witcher, David Thirtyacre, Adeel Khalid

Applied Aerospace Science

"The purpose of this research paper was to examine the influencing factors associated with the use of unmanned aerial system (UAS) technology to support aviation accident and emergency response. The ability of first responders to react to an emergency is dependent on the quality, accuracy, timeliness, and usability of information. With aviation accidents such as the Asiana Airlines Flight 214 crash at San Francisco International Airport, the ability to sense and communicate the location of victims may reduce the potential for accidental passenger death. Furthermore, the ability to obtain information en-route to an accident may also to assist to reduce …

Design Of Synthetic Jet Actuator For Flight Control Of Small Uav, Priyanka Pagadala

Doctoral Dissertations and Master's Theses

The main idea of this project is to develop a prototype SJA - Synthetic Jet Actuator to embed into a small UAV with modified Glauert wing cross-section for Active Flow Control. Apart from lift enhancement, drag reduction, or separation control, etc; LCO suppression might be possible by modifying the boundary layer through the use of these actuators. For initial investigation, a wing section with span of 12.4 cm and chord of 14 cm was fabricated and tests were conducted in the subsonic wind tunnel at the free stream velocities of 5 and 10 m / s. From these experiments, lift …