Aerospace Engineering Commons^™

Numerical Modeling Of Synthetic Vortical Disturbance Interactions Using Openfoam, Ahmed Bilal

Doctoral Dissertations and Master's Theses

Nowadays, the number of Advance Air Mobility (AAM) Electic Vertical Take-off and Landing (eVTOL) concepts is rapidly increasing due to their capability of vertical take-off and landing at vertiports located on rooftops of tall urban buildings, which does not require using the ground space in a condensed urban environment. Such flight operations, however, will be greatly affected by the vertiport’s highly unsteady, turbulent flow environment. The goal of this study is to model the turbulent wind interaction with a building to understand the unsteady flow characteristics around vertiports and match the induced unsteady disturbance field to the canonical disturbance forms, …

Nonlinear Dynamics Analysis And Control Of Space Vehicles With Flexible Structures, Marco Fagetti

Doctoral Dissertations and Master's Theses

Space vehicles that implement hardware such as antennas, solar panels, and other extended appendages necessary for their respective missions must consider the nonlinear rotational and vibrational dynamics of these flexible structures. Formulation and analysis of these flexible structures must account for the rigid-flexible coupling present in the system dynamics for stability analysis and control design. The system model is represented by a flexible appendage attached to a central rigid body, where the flexible appendage is modeled as a cantilevered Euler-Bernoulli beam. Discretization techniques, such as the assumed modes method and the finite element method, are used to model the coupled …

The Linearized Euler Equations For Predicting Supersonic Jet Noise Of A Rectangular Jet Using Openfoam, Patrick Good

Doctoral Dissertations and Master's Theses

This thesis presents a Linearized Euler Equation (LEE) solver that was developed for OpenFOAM. OpenFOAM is an open-source Computational Fluid Dynamics (CFD) package that is widely used by industry and academia. The LEE’s are a set of equations used in Computational Aeroacoustics (CAA). The LEE’s can solve for the acoustic solution directly and quickly. The solver developed, named leeFoam, was tested against analytical solutions to verify accuracy and then was utilized to predict the acoustics of a heated supersonic rectangular jet. The rectangular jet (RJET) results were compared against experimental data.

The results from this work show that OpenFOAM can …

Characterization Of Bistability Behavior In Unsymmetric Cfrp Laminates, Evan Medora

Doctoral Dissertations and Master's Theses

Composite laminates of unsymmetric layup families often exhibit twin stable shapes at room temperature, a phenomenon known as bistability. Unsymmetric bistable composite laminates have often been suggested for applications in aerospace morphing structures, damping, and energy storage, because of their ability to easily change their shape while being homogenized with the rest of the composite structure.

This study analyzes the mechanisms responsible for bistability in unsymmetrical [0/0/90/90] laminates through a combination of experiments and modeling. Several unsymmetrical laminates with different aspect ratios were fabricated using autoclave processing. Digital image correlation (DIC) is used to monitor laminate strains in situ during …

Prediction & Active Control Of Multi-Rotor Noise, Samuel O. Afari

Doctoral Dissertations and Master's Theses

Significant developments have been made in designing and implementation of Advanced Air Mobility Vehicles (AAMV). However, wider applications in urban areas require addressing several challenges, such as safety and quietness. These vehicles differ from conventional helicopter in that they operate at a relatively lower Reynolds number. More chiefly, they operate with multiples of rotors, which may pose some issues aerodynamically, as well as acoustically. The aim of this research is to first investigate the various noise sources in multi-rotor systems. High-fidelity simulations of two in-line counter-rotating propellers in hover, and in forward flight conditions are performed. Near field flow and …

Loss Of Control In-Flight (Loc-I): A Mixed Methods Study Of Voluntary Versus Mandatory Reports From The United States Of America, Roger Lee

Doctoral Dissertations and Master's Theses

Loss of control in flight (LOC-I) is one of modern aviation’s three most prominent fatal accidents. In the United States, air accidents are mandatorily reported to and investigated by the National Transportation Safety Board (NTSB). Established in 1976, the Air Safety Reporting System (ASRS) is a voluntary safety reporting (VSR) system administered by the National Aeronautics and Space Administration (NASA). Over 1.7 million ASRS reports have been processed to date. While the NTSB system handles LOC-I accidents, less severe incidents may have been reported voluntarily through the ASRS.

Safety reporting has been deemed the most valuable activity and the centerpiece …

A Simulation Of The Impacts Of Climate Change On Civil Aircraft Takeoff Performance, Thomas D. Pellegrin

Doctoral Dissertations and Master's Theses

Climate change affects the near-surface environmental conditions that prevail at airports worldwide. Among these, air density and headwind speed are major determinants of takeoff performance, and their sensitivity to global warming carries potential operational and economic implications for the commercial air transport industry. Previous archival and prospective research observed a weakening in headwind strength and predicted an increase in near-surface temperatures, respectively, resulting in an increase in takeoff distances and weight restrictions. The main purpose of the present study was to update and generalize the extant prospective research using a more representative sample of worldwide airports, a wider range of …

Small Unmanned Aircraft Systems: Operator Workload And Situation Awareness Utilizing First Person View Techniques, Ross Lucas Stephenson Jr

Doctoral Dissertations and Master's Theses

The small, unmanned aircraft systems (sUAS) sector within the aviation industry is experiencing unprecedented growth. However, the regulatory guidance for the safe integration of sUAS into the National Airspace System (NAS) has not kept pace with this technological growth within the market. Current regulatory limitations of line-of-sight operations may have an impact on the establishment of an equivalent level of safety for sUAS operations as maintained by manned aircraft. The focal point of the discussion of line-of-sight operations has been the ability of the sUAS pilot to see and avoid all obstacles and other aircraft in a safe and timely …

Autonomous Space Surveillance For Arbitrary Domains, David Zuehlke

Doctoral Dissertations and Master's Theses

Space is becoming increasingly congested every day and the task of accurately tracking satellites is paramount for the continued safe operation of both manned and unmanned space missions. In addition to new spacecraft launches, satellite break-up events and collisions generate large amounts of orbital debris dramatically increasing the number of orbiting objects with each such event. In order to prevent collisions and protect both life and property in orbit, accurate knowledge of the position of orbiting objects is necessary. Space Domain Awareness (SDA) used interchangeably with Space Situational Awareness (SSA), are the names given to the daunting task of tracking …

Understanding The Structure Of Wing Tip Vortices Of Bio-Inspired Winglets, Greeshma C. Daniel

Doctoral Dissertations and Master's Theses

Bio-inspired wing tip devices were investigated with the goal of improving the fuel efficiency of subsonic aircraft. Particularly, the structure of a bio-inspired winglet design based on bird feathers were tested in a low-speed wind tunnel. Particle image velocimetry (PIV), was used to study the flow field at two planes aft of the wing as the wing tip vortices developed downstream. These were time-dependent, stereoscopic particle image velocimetry (sPIV) measurements carried out at two planes located at 0.7 and 2 chord distances downstream from the wing. The structure of the wingtip vortices was compared and contrasted with that formed over …

Optical Orbit Tracking And Estimation, Matthew Gillette

Doctoral Dissertations and Master's Theses

Angles-only initial orbit determination methods are currently limited in their use as they require some prior knowledge of where the observed object will be and when it will be there. This research aims to produce a viable method to automate this process so that objects whose trajectories are not saved in a user’s catalog can be observed. A method is devised using a novel approach to satellite recognition in an image. This method is used in addition to Astrometry to determine the right ascension and declination of the object. This information is then used to either obtain the initial conditions …

Adaptive Modified Rise-Based Quadrotor Trajectory Tracking With Actuator Uncertainty Compensation, Emmanuel Ogbanje Ijoga, William Mackunis, Krishna Bhavithavya Kidambi, Madhur Tiwari

Publications

This paper presents an adaptive robust nonlinear control method, which achieves reliable trajectory tracking control for a quadrotor unmanned aerial vehicle in the presence of gyroscopic effects, rotor dynamics, and external disturbances. Through novel mathematical manipulation in the error system development, the quadrotor dynamics are expressed in a control-oriented form, which explicitly incorporates the uncertainty in the gyroscopic term and control actuation term. An adaptive robust nonlinear control law is then designed to stabilize both the position and attitude loops of the quadrotor system. A rigorous Lyapunov-based analysis is utilized to prove asymptotic trajectory tracking, where the region of convergence …

Evaluating System Usability, Workload Suitability, And User Experience Of Game-Based Virtual Reality In Spaceflight Education And Training, Lana Laskey, Joseph R. Keebler

Journal of Aviation/Aerospace Education & Research

Game-based instruction and immersive virtual reality are enhanced pedagogical methods beneficial in training environments involving complex disciplines, ranging from medical applications to construction engineering technology. This study investigated the use of game-based virtual reality (GBVR) when applied to the complex field of spaceflight education and training. As modern society places increasing demand on space-based amenities, the need for proficient satellite operators will also increase, requiring more accessible and advanced training options. Satellite ground control training scenarios, immersed in the GBVR environment, were developed and deployed to university student participants. Multiple validated scales were employed to measure the GBVR system regarding …

Urban Air Mobility (Uam) Flight Path: Literature Review And Conceptual Design Of Uam Corridor Virtual Lane System Using “Tracks”, Immanuel Bankole

Student Works

As the Urban Air Mobility (UAM) industry grows and becomes more popular, most of the conversations in the public domain are focused on the (electric Vertical Take-off and Landing) eVTOL aircraft and the physical infrastructure that will support these eVTOL aircraft. However, there is a lack of research on UAM traffic management and flight paths taken by aircraft between locations.

The United States (U.S.) Federal Aviation Administration has proposed the use of corridors to minimize the interaction between UAM operations and traditional air traffic as eVTOL aircraft perform flight activities. The government also acknowledges the need for additional structures (such …

A Bidirectional Deep Lstm Machine Learning Method For Flight Delay Modelling And Analysis, Desmond B. Bisandu, Irene Moulitsas

National Training Aircraft Symposium (NTAS)

Flight delays can be prevented by providing a reference point from an accurate prediction model because predicting flight delays is a problem with a specific space. Only a few algorithms consider predicted classes' mutual correlation during flight delay classification or prediction modelling tasks. None of these existing methods works for all scenarios. Therefore, the need to investigate the performance of more models in solving the problem of flight delay is vast and rapidly increasing. This paper presents the development and evaluation of LSTM and BiLSTM models by comparing them for a flight delay prediction. The LSTM does the feature extraction …

The Impacts Of Advanced Avionics On Degraded Visual Environments, Sultan Naseeb Harib Fairouz Mubarak, Anju Anna Jacob Dr

International Journal of Aviation, Aeronautics, and Aerospace

Degraded visual environments (DVE) such as brownout, sand storms, and night conditions are responsible for accidents and hence losses in the aviation industry. There is a need to develop avionic systems to support pilots when they encounter environmental conditions that compromise their visual capacity. This report discusses the effects of DVEs on aviation, expounds on the advanced avionic systems available and further elaborates how these systems are implemented in countering DVE conditions. The report recommends on how advanced avionics systems have been and are being implemented in aircrafts to support decisions made by pilots flying under degraded visual environments.

Accuracy Assessment Of The Ebee Using Rtk And Ppk Corrections Methods As A Function Of Distance To A Gnss Base Station, Joseph Cerreta, David Thirtyacre, Peter Miller, Scott S. Burgess, William J. Austin

International Journal of Aviation, Aeronautics, and Aerospace

The use of unmanned aircraft systems to collect data for photogrammetry models has grown significantly in recent years. The accuracy of a photogrammetric model can depend on image georeferencing. The distance from a reference base station can affect the accuracy of the results. Positioning corrections data relies on precise timing measurements of satellite signals. The signals travel through the Earth's atmosphere, which introduces errors due to ionospheric and tropospheric delays. The aim of this research was to examine the eBee X and its global GNSS accuracy by comparing the RTK and PPK methods at different base station distances in photogrammetry …

Stochastic Optimization To Reduce Aircraft Taxi-In Time At Igia, New Delhi, Rajib Das, Saileswar Ghosh, Rajendra Desai, Pijus Kanti Bhuin, Stuti Agarwal

International Journal of Aviation, Aeronautics, and Aerospace

Since there is an uncertainty in the arrival times of flights, pre-scheduled allocation of runways and stands and the subsequent first-come-first-served treatment results in a sub-optimal allocation of runways and stands, this is the prime reason for the unusual delays in taxi-in times at IGIA, New Delhi.

We simulated the arrival pattern of aircraft and utilized stochastic optimization to arrive at the best runway-stands allocation for a day. Optimization is done using a GRG Non-Linear algorithm in the Frontline Systems Analytic Solver platform. We applied this model to eight representative scenarios of two different days. Our results show that without …

Air Traffic Management Principles: A Case Study On How To Create A Sustainable System, Eva Maleviti

Publications

BEYOND ENVIRONMENTAL SUSTAINABILITY

• Emissions, SAF, CORSIA, Design
• Economic growth and development
• Sustainability should go beyond environment
• Non-technology approaches for sustainability and Net-Zero targets
• What about social sustainability and people?

In the total share of aviation emissions (1GT CO2) 3% is 3Mt CO2. Small share but very significant contribution.

Fostering Safer Evacuations Aboard Commercial Aircraft: A Problem-Solution Analysis, George Skinner

Student Works

This problem-solution analysis analyzes factors impeding safe and orderly evacuations for the Federal Aviation Administration (FAA). Although rarely used, evacuation procedures are critical for keeping passengers safe during emergency situations. However, there are flaws in these procedures and many factors exist which make aircraft evacuations slow and dangerous. During a situation in which time is of the essence, these impediments can make the difference between an incident and a fatal accident. This report focuses on data gathered through full-scale evacuation simulations and analyzes shortcomings and strengths in three accidents. This information is then compared to current procedures and regulations that …

Solar Sailing Adaptive Control Using Integral Concurrent Learning For Solar Flux Estimation, Luis Enrique Mendoza Zambrano, Riccardo Bevilacqua

Student Works

In the interest of exploiting natural forces for propellant-less spacecraft missions, this investigation proposes an adaptive control strategy to account for unknown parameters in the dynamic modeling of a reflectivity-controlled solar sail spacecraft. A Lyapunov-based control law along with integral concurrent learning is suggested to accomplish and prove global exponential tracking of the estimated parameters and states of interest, without satisfying the common persistence of excitation condition, which in most nonlinear systems cannot be guaranteed a priori. This involves estimating the solar flux or irradiance from the Sun to account for uncertainty and variation over time in this value. To …

Dual Quaternion Relative Dynamics For Gravity Recovery Missions, Ryan Kinzie, Riccardo Bevilacqua, Seo Dongeun

Student Works

A dual quaternion modeling approach is compared to traditional modeling methods for formation flying spacecraft utilized for gravity recovery missions. A modeling method that has traditionally been used for gravity recovery missions is presented which models the motion of two formation flying spacecraft and a test mass. This is followed by the dual quaternion-based formulation for the equations of motion of the twelve degree-of-freedom coupled relative dynamics of formation flying spacecraft and a test mass. Lastly, utilizing data products from the Gravity Recovery and Climate Experiment Follow-On mission, a comparison of these two modeling methods is presented which proves the …

Experimental Validation Of Inertia Parameters And Attitude Estimation Of Uncooperative Space Targets Using Solid State Lidar, Alessia Nocerino, Roberto Opromolla, Giancarmine Fasano, Michele Grassi, Spencer John, Hancheol Cho, Riccardo Bevilacqua

Student Works

This paper presents an experimental activity aimed at assessing performance of techniques for inertia and attitude parameters estimation of an uncooperative but known space target. The adopted experimental set-up includes a scaled-down 3D printed satellite mock-up, a spherical air bearing and a low-cost solid-state LIDAR. The experimental facility also comprises a motion capture system to obtain a benchmark of the pose (position and attitude) parameters and an ad-hoc designed passive balancing system to keep the centre of mass as close as possible to the centre of rotation. The LIDAR-based 3D point clouds, collected while the target rotates on the spherical …

Ads-B Communication Interference In Air Traffic Management, George Ray

International Journal of Aviation, Aeronautics, and Aerospace

Automated Dependent Surveillance Broadcast (ADS-B) provides position and state information about aircraft and is becoming an essential component in the global air traffic management system. ADS-B transponders broadcast this key information on a common frequency to both other aircraft and to secondary surveillance radar systems located at ground stations. Both the aircraft transponders and the ground stations work together to assist in managing the commercial airspace. Since the aircraft transponders all broadcast on the same frequency and are in close proximity there is an apparent risk of interference and the garbling of the communications needed to manage the airspace.

The …

Statistical Analysis To Evaluate The Impact Of Quality Control And Quality Assurance On The Aircraft Maintenance Turnaround Time, Deepak Chandra Chandola, Seema Verma, Kamal Jaiswal, Rajendrra Prasad Khaolliya, Preeti Chandola

International Journal of Aviation, Aeronautics, and Aerospace

The turnover time for aircraft maintenance is crucial for the operational efficiency and profitability of airlines. Quality assurance (QA) and quality control (QC) procedures play a role in assuring the safe and reliable operation of aircraft. The purpose of this paper is to evaluate the impact of QC and QA on turnover time and to propose strategies for achieving a balance between quality and efficiency. A large-scale survey of airline and aviation maintenance organization maintenance staff was combined with a literature study to form a mixed-methods strategy. The findings indicate that quality control and quality assurance have a substantial impact …

Enhancing Trajectory-Based Operations For Uavs Through Hexagonal Grid Indexing: A Step Towards 4d Integration Of Utm And Atm, Deepudev Sahadevan Neelakandan, Hannah Al Ali

International Journal of Aviation, Aeronautics, and Aerospace

Aviation is expected to face a surge in the number of manned aircraft and drones in the coming years, making it necessary to integrate Unmanned Aircraft System Traffic Management (UTM) into Air Traffic Management (ATM) to ensure safe and efficient operations. This research proposes a novel hexagonal grid-based 4D trajectory representation framework for unmanned aerial vehicle (UAV) traffic management that overcomes the limitations of existing square/cubic trajectory representation methods. The proposed model employs a hierarchical indexing structure using hexagonal cells, enabling efficient ground based strategic conflict detection and conflict free 4D trajectory planning. Additionally, the use of Hexagonal Discrete Global …

Future Directions Of Space Education, Kimberly T. Luthi Dr., Andy Aldrin, Keith Wilson, Jim P. Solti

International Journal of Aviation, Aeronautics, and Aerospace

The future of space operations graduate education is reliant on industry leaders’ contributions to help forecast the needs of the industry. The aim of the current study is to build consensus on the future direction of the space industry and generate new knowledge on what the industry expects to occur in the future of space studies education. This study documents the responses of 14 industry experts who currently or previously held highly visible senior leadership positions in a company or organization within the government or the commercial space industry and have extensive experience in a variety of management and leadership …

Design Of An Internal Osculating Waverider Intake, Mark E. Noftz, Andrew J. Shuck, Joseph S. Jewell, Jonathan Poggie, Andrew N. Bustard, Thomas J. Juliano, Nicholas J. Bisek

Publications

The design of an inward-turning, high-speed, three-dimensional streamline traced intake is presented from osculating axisymmetric theory. To satisfy the osculating intake design criteria, a stitched Busemann diffuser and Internal Conical Flow-A solution is used as the basic isentropic compressive streamline. This new contour provides efficient compression, high flow uniformity, and straight leading edge shocks of equal strength. Additionally, a novel method for constructing the inlet cowl is presented. The combined process leads to a new method of high-speed intake design. A generic shape-transitioned intake is constructed and named the Indiana Inlet for the Indiana universities that contributed to the project. …

Alternatives To Reducing Aviation Fuel-Burn With Technology: Fully Electric Autonomous Taxibot, Denzil Neo

Student Works

Aircraft taxiing operations in the aerodrome were identified to consume the most jet fuel apart from the cruise phase of the flight. This was also well supported by various research associating taxi operations at large, congested airports, with high jet fuel consumption, high carbon emissions, and noise pollution. Existing literature recognised the potential to address the environmental issues of aerodrome taxi operations by operating External or Onboard Aircraft Ground Propulsion Systems (AGPS). Designed to power aircraft with sources other than their main engines, external Aircraft Ground Power Systems (AGPS) have shown the potential to significantly cut jet fuel consumption and …

Noise Reduction Techniques In Commercial Aircraft Cabins, Hashem Hashem

Student Works

Main sources of noise heard inside an aircraft cabin:

• Engines
• Airframe & control surfaces
• Window vibrations
• Passenger announcements & activities.