Engineering Commons^™

Six Degree Of Freedom Dynamic Modeling Of A High Altitude Airship And Its Trajectory Optimization Using Direct Collocation Method, Pradens Pierre-Louis

Electronic Theses and Dissertations

The long duration airborne feature of airships makes them an attractive solution for many military and civil applications such as long-endurance surveillance, reconnaissance, environment monitoring, communication utilities, and energy harvesting. To achieve a minimum energy periodic motion in the air, an optimal trajectory problem is solved using basic direct collocation methods. In the direct approach, the optimal control problem is converted into a nonlinear programming (NLP). Pseudo-inverse and several discretization methods such as Trapezoidal and Hermite-Simpson are used to obtain a numerical approximated solution by discretizing the states and controls into a set of equal nodes. These nodes are approximated …

Long And Short-Range Air Navigation On Spherical Earth, Nihad E. Daidzic

International Journal of Aviation, Aeronautics, and Aerospace

Global range air navigation implies non-stop flight between any two airports on Earth. Such effort would require airplanes with the operational air range of at least 12,500 NM which is about 40-60% longer than anything existing in commercial air transport today. Air transportation economy requires flying shortest distance, which in the case of spherical Earth are Orthodrome arcs. Rhumb-line navigation has little practical use in long-range flights, but has been presented for historical reasons and for comparison. Database of about 50 major international airports from every corner of the world has been designed and used in testing and route validation. …

Intercomparison Of Modis And Viirs Fire Products In Khanty-Mansiysk Russia: Implications For Characterizing Gas Flaring From Space, Ambrish Sharma, Jun Wang, Elizabeth M. Lennartson

Department of Earth and Atmospheric Sciences: Faculty Publications

Gas flaring is commonly used by industrial plants for processing oil and natural gases in the atmosphere, and hence is an important anthropogenic source for various pollutants including CO₂, CO, and aerosols. This study evaluates the feasibility of using satellite data to characterize gas flaring from space by focusing on the Khanty-Mansiysk Autonomous Okrug in Russia, a region that is well known for its dominant gas flaring activities. Multiple satellite-based thermal anomaly data products at night are intercompared and analyzed, including MODIS (Moderate Resolution Imaging Spectroradiometer) Terra level 2 Thermal Anomalies product (MOD14), MODIS Aqua level 2 Thermal …

Spacex: Breaking The Barrier To The Space Launch Vehicle Industry, Matthew M. Liskowcyz

Theses and Dissertations

The Space Launch Vehicle (SLV) industry has been around for a long time, but few companies have managed to enter this industry. SpaceX was founded only 10 years ago, but it has managed to become a leader in the U.S. industry and a dominant player worldwide. The purpose of this thesis research is to discover what it took for SpaceX to break into this tightly controlled industry. A qualitative analysis was performed to compare SpaceX to companies that overcame the barriers of entry for their respective industries. SpaceX, like FedEx, could implement a unique technique to the industry and find …

System Health Monitoring Using Multiple-Model Adaptive Estimation Techniques, Stanley Ryan Sifford

Mechanical and Aerospace Engineering Dissertations - Archive

Monitoring system health for fault detection and diagnosis by tracking system parameters concurrently with state estimates is approached using a new multiple-model adaptive estimation (MMAE) method. This novel method is called GRid-based Adaptive Parameter Estimation (GRAPE). GRAPE expands existing MMAE methods by using new techniques to sample the parameter space. GRAPE expands on MMAE with the hypothesis that sample models can be applied and resampled without relying on a predefined set of models. GRAPE is initially implemented in a linear framework using Kalman filter models. A more generalized GRAPE formulation is presented using extended Kalman filter (EKF) models to represent …

Evaluation Of Water Consumption And Savings Achieved In Datacenters Through Air Side Economization, Ravi Mishra

Mechanical and Aerospace Engineering Theses - Archive

Recent researches and a few facility owners have focused on eliminating the chiller plant altogether by implementing ‘Evaporative Cooling’, as an alternative or augmentation to compressor-based air conditioning since the energy consumption is dominated by the compressor work (around 41%) in the chiller plant. Because evaporative cooling systems consume water, when evaluating the energy savings potential of these systems, it is imperative to consider not just their impacts on electricity use, but also their impacts on water consumption as well since Joe Kava, Google’s head of data center operations, was quoted as saying that water is the “big elephant in …

Virginia Space Pocketqube Launch Opportunity, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint presentation created by Professor Bob Twiggs titled "Virginia Space PocketQube Launch Opportunity" from December 1, 2016.

Want To Be A Space Scientist For All Ages?, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "Want to be a Space Scientistfor all ages?" from November 8, 2016.

Study Of Surface Tension, Natural Evaporation, And Subcooled Boiling Evaporation Of Aqueous Surfactant Solutions, Matthew John Lehman

Doctoral Dissertations and Master's Theses

The relation between surface tension and surfactant concentration and its effect on solution evaporation under natural convection and subcooled pool boiling is examined through experimental methods. Aqueous solutions of sodium lauryl sulfate (SLS), ECOSURFTM EH-14, and ECOSURFTM SA-9 are used in this study. SLS is an anionic surfactant while EH-14 and SA-9 are environmentally-friendly nonionic surfactants.

Surfactants, surface active agents, are known to affect evaporation performance of solutions and are studied in relation to water loss prevention and heat dissipation. Surfactants could be useful under drought conditions which present challenges to water management on a yearly basis in arid areas …

Measurements By Controlled Meteorological Balloons In Coastal Areas Of Antarctica, Lars R. Hole, Alexis Pérez Bello, Tjarda J. Roberts, Paul B. Voss, Timo Vihma

Engineering: Faculty Publications

An experiment applying controlled meteorological (CMET) balloons near the coast of Dronning Maud Land, Antarctica, in January 2013 is described. Two balloons were airborne for 60 and 106 hours with trajectory lengths of 885.8 km and 2367.4 km, respectively. The balloons carried out multiple controlled soundings on the atmospheric pressure, temperature and humidity up to 3.3 km. Wind speed and direction were derived from the balloon drift. Observations were compared with radiosonde sounding profiles from the Halley Research Station, and applied in evaluating simulations carried out with the weather research and forecasting (WRF) mesoscale atmospheric model. The most interesting feature …

Investigation Of Exothermic Reaction Dynamics Via Computational Fluid Dynamics Coupled With A Feedback Controller, Siusan Choi

Mechanical and Aerospace Engineering Dissertations - Archive

The control of reaction temperature under continuous flow conditions is important in a variety of chemical manufacturing industries. For many reactions, operating at off-design temperatures can result in the production of undesired products, reduced feedstock conversion and, in some cases, reduced catalyst lifetime. In many exothermic reactions, maintaining a desired set point temperature at high reactant flow rates becomes challenging if the chemical kinetics exhibit highly non-linear behavior. In these situations, the interaction between commonly used linear controllers and the physical system can lead to unexpected dynamic response and undesired swings in reaction temperature. In this research, a computational model …

Analysis And Implementation Of Communications Systems For Small Satellite Missions, Jason S. Harris

Electrical & Computer Engineering Theses & Dissertations

Nano satellites are becoming more and more popular space platforms due to their relatively low cost. Constellations of many of these small satellites are being launched for scientific and research purposes. This thesis has examined implementing a communications system for small satellites that can be used to maintain constant contact with satellites as they orbit the Earth. It analyzes the various components of a small satellite and how they integrate. It then discusses the different abstraction layers that will be required in order to support the same software architecture across various types of hardware. An orbital analysis was performed to …

Meeting The Dod’S Tactical Weather Needs Using Cubesats, Shayna K. Mckenney

Theses and Dissertations

This thesis investigates a CubeSat design that uses Commercial-Off-The-Shelf (COTS) components to capture, store, process, and downlink collected terrestrial weather data at resolutions near stat-of-the-art. The weather phenomena to be detected and transmitted in a timely manner are cloud formations, wind profiles, ocean currents, sea state, lightning, temperature profiles, and precipitation. It is hypothesized and shown that the proposed design will provide an improvement on the current U.S. tactical weather collection satellites because of the anticipated increased reliability and lowered cost to build and maintain the proposed CubeSat constellation. The methodology employed a multi-phase approach through the collective research of …

Flow Meter Test Rig, Cory Davis, Emily Guss, Michael Swartz

Mechanical Engineering

As part of a fluid mechanics laboratory, there should be an experiment that demonstrates the proper use of flow meters, devices that are necessary and relevant in many fluids-related industries. In order to provide students with exposure to these types of devices and how they work, a test rig was developed with the ability to interchange a variety of flow meters in order to broaden the students’ knowledge of the different types of measuring devices. This report was also written to outline the steps taken to ensure the test rig would match a laboratory and industry setting. Additionally, it was …

Harvesting Of Water From Fog Using Sponges, Jae Jun Lee

Mechanical and Aerospace Engineering Theses - Archive

Supervising Professor: Cheng Luo A sponge has porous structures. It is capable of both storing and transmitting water. In this work, we explored the possibility of applying three different types of sponges to collect fog. We also compared their fog-collection efficiencies with that of a typical Raschel mesh that is widely used in the field to collect fog. We found that, for three different fog speeds, the fog-collection efficiencies of three tested sponges were 39% to 93% those of the typical Raschel mesh, indicating that the sponges could serve as alternative fog collectors when well-developed collectors were not available. Sponge …

Examining American Attitudes On The Use Of Military Drones, Todd Brandon

Political Science Theses and Capstones

Recent polls have revealed that Americans of both the political left and right support the use of military drones. This statement stands true among groups who traditionally do not support the use of military force. I hypothesize that people of a more liberal persuasion will be more concerned with whether or not the drone program endangers innocent civilians, while those of a more conservative view will be more concerned with the legality of conducting military drone strikes. I analyze data obtained from the Pew Research Center to examine people's attitudes on military drone strikes via framing theory. My hypothesis has …

Real-Time Implementation Of Vision-Aided Monocular Navigation For Small Fixed-Wing Unmanned Aerial Systems, Timothy I. Machin

Theses and Dissertations

The goal of this project was to develop and implement algorithms to demonstrate real-time positioning of a UAV using a monocular camera combined with previously collected orthorectified imagery. Unlike previous tests, this project did not utilize a full inertial navigation system (INS) for attitude, but instead had to rely on the attitude obtained by inexpensive commercial off-the-shelf (COTS) autopilots. The system consisted of primarily COTS components and open-source software, and was own over Camp Atterbury, IN for a sequence of flight tests in Fall 2015. The system obtained valid solutions over much of the flight path, identifying features in the …

Early Afternoon Concurrent Panel Sessions: Commercial Space Industry Snapshot: Presentation: Small Catapult-Assisted Horizontal-Launch Reusable Rbcc Ssto Spaceplane For Economical Short-Duration Leo Access, Nihad E. Daidzic,

Aviation / Aeronautics / Aerospace International Research Conference

This article discusses the conceptual design, flight trajectory calculations, and utilization of the possible future horizontally-launched reusable Single-Stage-to-Orbit (SSTO) spaceplane for small payload short-duration manned/unmanned access to Low-Earth-Orbit (LEO). The 10,000 lb spaceplane would use 5,000 ft catapult-assist horizontal-launch facility and conduct powered approach and landing on conventional horizontal paved runways following the gliding atmospheric re-entry. To increase the economy of operation, the launch facility located at high elevations (4,000+ ft) equatorial region is required, such as, the plateaus in Kenya and Tanzania in Africa and/or Ecuador in South America. A 500-lb payload, including pilot-commander, is envisioned. The propulsion cycle …

Design And Development Of The Sunswift Eve Solar Vehicle: World's Fastest Long-Range Electric Car, Sam Paterson, Pujith Vijayaratnam, Charith Perera, Graham Doig

Aerospace Engineering

The Sunswift project of the University of New South Wales, Australia, exists to provide university students with a multi-disciplinary engineering challenge, enhancing the true educational value of their degree with a unique hands-on real-world experience of creating solar–electric hybrid vehicles. The design and development of the low-drag ‘solar supercar’ Sunswift eVe car are described here, detailing the student-led process from initial concept sketches to the completed performance vehicle. eVe was designed to demonstrate the potential of effective solar integration into a practical passenger-carrying vehicle. It is a two-seater vehicle with an on-body solar array area of 4 m² and …

A Biomimetic, Energy-Harvesting, Obstacle-Avoiding, Path-Planning Algorithm For Uavs, Snorri Gudmundsson

Doctoral Dissertations and Master's Theses

This dissertation presents two new approaches to energy harvesting for Unmanned Aerial Vehicles (UAV). One method is based on the Potential Flow Method (PFM); the other method seeds a wind-field map based on updraft peak analysis and then applies a variant of the Bellman-Ford algorithm to find the minimum-cost path. Both methods are enhanced by taking into account the performance characteristics of the aircraft using advanced performance theory. The combined approach yields five possible trajectories from which the one with the minimum energy cost is selected. The dissertation concludes by using the developed theory and modeling tools to simulate the …

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 …

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

Aviation Faculty Publications

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 …

Methods Of Processing Kenaf Chopped Strand Mats For Manufacturing Test Specimens And Composite Structures, Joshua W. Heil

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Every year in the United States, 10 to 11 million vehicles reach the end of their life cycle. Nearly all of these go to a recycling facility. After the recycling process is complete an average of 25% of each vehicle, by weight, goes to waste. This demonstrates the need to use natural fibers in parts that could be recycled, like parts that can be made from kenaf. There are many reasons to consider using natural/bio-fiber composites (bio-composites). These reasons include human health and environmental factors as well as advantages that natural fibers have over fiberglass, such as: lower costs and …

Mapping Regional Inundation With Spaceborne L-Band Sar, Bruce Chapman, Kyle Macdonald, Masanobu Shimada, Ake Rosenqvist, Ronny Schroeder, Laura Hess

Publications and Research

Shortly after the launch of ALOS PALSAR L-band SAR by the Japan Space Exploration Agency (JAXA), a program to develop an Earth Science Data Record (ESDR) for inundated wetlands was funded by NASA. Using established methodologies, extensive multi-temporal L-band ALOS ScanSAR data acquired bi-monthly by the PALSAR instrument onboard ALOS were used to classify the inundation state for South America for delivery as a component of this Inundated Wetlands ESDR (IW-ESDR) and in collaboration with JAXA’s ALOS Kyoto and Carbon Initiative science programme. We describe these methodologies and the final classification of the inundation state, then compared this with results …

Icao Aviation System Block Upgrades: A Method For Identifying Training Needs, Rebecca K. Lutte

Aviation Institute Faculty Publications

Since the mid-1970s, air traffic growth has expanded two-fold once every fifteen years (ICAO, 2013). The ICAO Global Air Navigation Plan (GANP) is a roadmap to achieve a “vision of an integrated, harmonized, and globally interoperable air traffic management (ATM) system” (ICAO, 2012, p. 1). A component of the GANP is the Aviation System Block Upgrades (ASBU), a framework for achieving that vision. A collaborative approach led by ICAO between public and private organizations and member states resulted in the development of the ASBU framework. However, obstacles exist for successful implementation. One area of concern is the need for training …

Vessel Traffic Service As A Maritime Security Tool : Vessel Traffic Management Information Systems (Vtmis) In Ghana, Joseph Akwasi Kuma

World Maritime University Dissertations

The dissertation is an assessment of the role of the VTMIS in enhancing efforts to bring down maritime security in the threats in the Gulf of Guinea in West Africa focusing on Ghana. According to the International Maritime Organisation (IMO), Vessel Traffic Service (VTS) is implemented by a Competent Authority to improve the safety and efficiency of vessel traffic and to protect the environment. Technological development today has led to significant improvements in vessel traffic service. Vessel Traffic Management Information Service is the integration of Management information systems to improve the quality of vessel traffic services. Vessel traffic services essentially …

Achieving Global Range In Future Subsonic And Supersonic Airplanes, Nihad E. Daidzic Ph.D., Sc.D.

International Journal of Aviation, Aeronautics, and Aerospace

No commercial airplane in service today is able to fly half great-circle distances over the globe and achieve the non-stop or the global range to any antipodal location on Earth. A subsonic jetliner has the optimum cruising speed at Mach numbers approaching the drag divergence Mach number while still preserving relatively high aerodynamic efficiency. Various fuel-flow laws were used to investigate the cruise performance of subsonic and supersonic aircraft. The effect of wind and aircraft weight and how it affects the optimal cruising airspeed was investigated. Of all different operational cruising techniques, the cruise-climb at high Mach numbers is the …

Optimum Path Planning For An Impaired Aircraft, Suzannah Bailey

Renée Crown University Honors Thesis Projects - All

Proportionally speaking, it is safer to travel by plane than any other form of transportation. However, in some parts of the world such as Africa, the lack of updated aircraft, instability within the region, and inexperience of flight crews contribute to a higher rate of aircraft incidents and accidents. This capstone combines elements from aerospace engineering, as well as international relations to create a program to mitigate these risks.

This new algorithm, the Bailey Algorithm, is very different from the commonly used Dijkstra Algorithm. Unlike Dijkstra, the Bailey Algorithm not only incorporates the distance traveled between cities, but it also …

A Low Cost Implementation Of Autonomous Takeoff And Landing For A Fixed Wing Uav, Thomas Carnes

Theses and Dissertations

The take-off and landing of an Unmanned Aerial Vehicle (UAV) is often the most critical and accident prone portion of its mission. This potential hazard coupled with the time and resources necessary to train a remote UAV pilot makes it desirable to have autonomous take-off and landing capabilities for UAVs. However, a robust, reliable, and accurate autonomous takeoff and landing capability for fixed-wing aircraft is not an available feature in many low-cost UAV flight control systems. This thesis describes the design of an autonomous take-off and landing algorithm implemented on an existing low-cost flight control system for a small fixed …

Traditional Boat Building: An Intersection Of Zanzibar’S Culture And Environment, Eric Levenson

Independent Study Project (ISP) Collection

This study examined traditional boat building on Uzi Island as a manifestation of Zanzibar’s relationship of environment and culture. Information was gathered about traditional boat building practices, the resource use and management pertaining to boats, the cultural reliance on boats, and local views on environment and conservation. This information showed that the people of Uzi Island were dependent on the use of traditional boats to maintain their livelihood, however the tree types used for boat building are being over-harvested. This tension of culture and environment exposed the need for conservation of Zanzibar’s natural resources in a manner that does not …