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Full-Text Articles in Aerospace Engineering
Crashworthiness Of Metallic Tubes Under Off-Axial Loading, Victor Manuel Bautista Katsalukha
Crashworthiness Of Metallic Tubes Under Off-Axial Loading, Victor Manuel Bautista Katsalukha
Theses and Dissertations
Energy absorbing structures (EAS) are structures used to make the frame of a vehicle absorb energy during an impact scenario and keep the deceleration forces within survivable limits for the occupant(s). These structures are found in all sorts of vehicles, such as cars, helicopters, airplanes, etc., and come in many types of shapes (circular, square, triangular tubes and flat or curved plates) and materials (metals and composites). In this thesis, 304 Stainless Steel tubes with circular and square cross-sections are investigated when subject to off-axis loading at angles at 0, 5, 15 and 25°. The square tubes had two different …
Helicopter Flight Energy Modeling And Scaling For Urban Air Mobility Applications, Nolan Gene Hopkins
Helicopter Flight Energy Modeling And Scaling For Urban Air Mobility Applications, Nolan Gene Hopkins
Theses and Dissertations
The costs associated with conducting full-scale helicopter flight tests in terms of both time and money beg to question the validity of using small-scale model helicopters in order to predict full-scale performance. To do this, the energy change for a small time interval is determined throughout a full-scale helicopter’s flight of a given profile, and the overall energy use compared to model results. The profile is then scaled based on a variety of factors, and the accuracy of energy scaling compared for each. Scaling dimensions based off helicopter weight and energy reserve modeling show promising results, but comparison of relative …
Flight Test Evaluation Of Elevator Stick Force Gradients On General Aviation Aircraft, Isaac Lee Faust
Flight Test Evaluation Of Elevator Stick Force Gradients On General Aviation Aircraft, Isaac Lee Faust
Theses and Dissertations
The objective of this research is to establish a suitable method of changing elevator stick force gradients on a Piper Warrior II. After finding a range of stick force gradients, the gradients will later be evaluated to get handling qualities ratings. A stick force gradient is the change in stick force as the airspeed deviates from trim condition. An aircraft’s yoke force gives pilots haptic feedback which improves their situational awareness without the need to assess instrument readings. A high stick force gradient will give the pilots a lot of feedback but will require more physical exertion to fly the …
Feasibility Analysis And Performance Study Of A Pulsed Solid Propellant Integrated Propulsion System For Small Satellites, Tahir Kanchwala
Feasibility Analysis And Performance Study Of A Pulsed Solid Propellant Integrated Propulsion System For Small Satellites, Tahir Kanchwala
Theses and Dissertations
Solid propellant has come a long way since the 13th century when gunpowder was widely used as the go-to means in rocket propulsion. Of course, back then, rockets were not intended to carry humanity out of the atmosphere. Untill the introduction of liquid propellants in the mid-20th century, solid propellants were the foundation. Still, liquid propellants aimed to add more stability and controllability to rocketry and thus were preferred over their solid counterparts. This thesis seeks to analyze a novel type of propulsive device that aims to eliminate challenges faced by both types of fuels and instead utilize the advantages …
Numerical Validation Of A Cryogenic Thermo-Fluid Mixing Model, Sean William Bowman
Numerical Validation Of A Cryogenic Thermo-Fluid Mixing Model, Sean William Bowman
Theses and Dissertations
Thermal management of a hot convective gaseous flow can be achieved by the injection of a cold liquid stream. This cooling effect is constrained by the amount of liquid injected, the rate of evaporation of the liquid, and the length of the domain. In this study, such a domain is referred to as a “mixer”. The mixer used to facilitate this process is designed with a venturi geometry, such that the throat of the pipe creates a drop in the static pressure of the gaseous crossflow. Liquid coolant can thereby be passively entrained from a central pipe (plenum) by the …
Experimental Study Of Progressive Crushing Behaviour In Pultruded E-Glass Tubes Using Crown Triggers And A New Perforated Trigger, Chirag Mohan Dodani
Experimental Study Of Progressive Crushing Behaviour In Pultruded E-Glass Tubes Using Crown Triggers And A New Perforated Trigger, Chirag Mohan Dodani
Theses and Dissertations
An experimental study is conducted on the progressive crushing behavior and the energy absorption during crushing of pultruded fiberglass tubes, initiated by two types of crush triggers, a previously tested crown trigger, and a new perforated trigger. These crush triggers are introduced at the loading end of a pultruded E-Glass/vinyl-ester, circular tube coupon. Coupons with various trigger diameters and number of holes are crushed under quasi-static compression, to evaluate the trigger effectiveness, crushing response, and energy absorption during sustained crushing. It is observed that all trigger types induced progressive crushing in the splaying mode, characterized by the formation of a …
Exploration Of Simplified Vehicle Operations For Electric Vertical Takeoff And Landing Through A Garmin Autopilot On A Piper Warrior, William Stefan Dietrich
Exploration Of Simplified Vehicle Operations For Electric Vertical Takeoff And Landing Through A Garmin Autopilot On A Piper Warrior, William Stefan Dietrich
Theses and Dissertations
Urban Air Mobility is an emerging concept that would allow urban transportation of both people and cargo through the air in large metropolitan cities. Because of new propulsion methods like distributed electrical propulsion, the Urban Air Mobility is concentrating on Electric Vertical Takeoff and Landing aircraft to implement its concept. Controlling and maneuvering these aircraft are very different than piloting traditional general aviation even through Electric Vertical Take and Landing aircraft aim to be in the same size category. Because of the more complex controls needed for Electric Takeoff and Landing aircraft, Simplified Vehicle Operation schemes are being developed in …
Autonomous Feature Detection For Capture Path Planning For Rendezvous And Docking With Non-Cooperative Spacecraft, Trupti Mahendrakar
Autonomous Feature Detection For Capture Path Planning For Rendezvous And Docking With Non-Cooperative Spacecraft, Trupti Mahendrakar
Theses and Dissertations
With the increasing risk of collisions with space debris and the growing interest in on-orbit servicing, the ability to autonomously capture non-cooperative, tumbling target objects remains an unresolved challenge. This thesis provides an autonomous and artificial intelligence solution to either inspect, avoid, or perform on-orbit spacecraft servicing of an uncooperative resident space object (RSO). The solution is built on the fundamentals of Convolutional Neural Networks (CNN), which is used to classify the four most targeted features of a spacecraft essential for docking and collision avoidance during rendezvous, such as solar panels, antennas, spacecraft bodies, and thrusters. The solution was then …
Scaling Flight Test Data Between A Scaled Aircraft And A Cessna 172 For Use In Trajectory Energy Model Validation, Cody William Nettleton
Scaling Flight Test Data Between A Scaled Aircraft And A Cessna 172 For Use In Trajectory Energy Model Validation, Cody William Nettleton
Theses and Dissertations
Currently in the general aviation sector, a new type of aircraft is rising to prominence. It is known as Urban Air Mobility (UAM) and takes many shapes and sizes. The goal of UAM is to produce aircraft that can be used to travel into and out of the city in an efficient manner through the sky. This may cut down on many people’s commutes and lower the amount of ground traffic in cities. One core component of UAM research is to determine the fuel consumption during phases of flight such as conventional takeoff and landing, as well as cruise travel …
Reduced Sample Minimum Strength Estimates For Novel Material Systems: Effects On Confidence And Structural Risk, Andrew Carl Ollikainen
Reduced Sample Minimum Strength Estimates For Novel Material Systems: Effects On Confidence And Structural Risk, Andrew Carl Ollikainen
Theses and Dissertations
There are ongoing efforts to standardize the materials, methods and process controls used in additive manufacturing. To support the broader use of additive manufacturing (AM) in the aerospace industry, the statistics working group of the Composite Materials Handbook (CMH-17) is evaluating whether its current methods of calculating minimum strength values are suitable for these new materials. The work presented in this dissertation investigates methods for determining minimum strength estimates in a way that will benefit application of AM materials in engineering practice. The greatest challenge in conducting such an assessment is accounting for the many variables in material, processing, and …
Stability And Control Flight Testing Of The Dassault Falcon 10/100, Andres Mauricio Alarcon Vega
Stability And Control Flight Testing Of The Dassault Falcon 10/100, Andres Mauricio Alarcon Vega
Theses and Dissertations
The Falcon 10/100 is a transport category aircraft developed by Dassault Aviation in 1971. Production of the aircraft ceased in 1989, but it remains available on the secondhand market. Certification for these types of aircraft follow FAR Part 25 of the code of federal regulations. Aircraft stability and control flying qualities are dependent on the mission profile and intended use case of the aircraft. External factors, such as turbulence, are relevant for transport category aircraft because poor stability could affect the flying characteristics and result in an unpleasant ride. On the other hand, in a trimmed condition, an aircraft with …
Hydrogen/Diesel Co-Combustion In Compression Ignition Engines Through Hydrogen Ingestion And Direct Hydrogen Injection, Helge Hening Von Helldorff-Garn
Hydrogen/Diesel Co-Combustion In Compression Ignition Engines Through Hydrogen Ingestion And Direct Hydrogen Injection, Helge Hening Von Helldorff-Garn
Theses and Dissertations
This dissertation develops, implements, and validates the computational tools necessary for the computational simulation of hydrogen-enhanced Diesel combustion for premixed hydrogen charges ingested into the intake air and for direct injected hydrogen pilot charges into the cylinder. This includes a dual-fuel mechanism, a Lagrangian gaseous injection scheme, an improved spray particle breakup model, an advanced chemical kinetic reaction solver, as well as a complex n-heptane chemical kinetic reaction mechanism consisting of 35 species and 119 reversible reactions capable of describing both premixed and mixing controlled hydrogen/Diesel co-combustion at various fuel concentrations. The results showed that low levels of either hydrogen …
Analytical Airflow Solution Of A Helicopter Engine Bay And Novel Bay Cooling Cowling Design, Daniel Evan Yastishock
Analytical Airflow Solution Of A Helicopter Engine Bay And Novel Bay Cooling Cowling Design, Daniel Evan Yastishock
Theses and Dissertations
The objective of this thesis is to develop an analytical-numerical solution for the engine bay cooling airflow in a representative helicopter based on the Augusta-Westland 101, and evaluate the performance of a novel rotating scoop cowling on the airflow. The methodology was created in PythonTM. Results obtained via the analytical method were compared against a CFD model constructed with Ansys® at a hover, 50 fps forward flight, and 250 feet per second forward flight using a k−ε turbulence model. Performance of the rotating scoop was compared to that of a conventional inlet orifice and fixed scoop in a similar airspeed …
Extraction Of Pendulum Model Parameters From Steady-State Slosh Data With Adaptive Gradient Descending Optimization Method For Spacecraft Propellant Tanks, Tengjie Gao
Theses and Dissertations
This thesis proposes a new experimental approach to extract pendulum model parameters from spacecraft propellant tank slosh data. The novelty of the approach is in the utilization of steady-state triaxial force measurements at the support points of the tank under sinusoidal excitation, which enables repeatable and accurate determination of pendulum model parameters in contrast to the single-axis force sensing and multiple repetitions averaging techniques associated with the more common decay approach. This approach may be used for tanks with free slosh; however, this thesis considers a diagram tank with three different diaphragm configurations under translational oscillatory lateral excitation. With the …
Design And Evaluation Of A Variable Camber Morphing Wing With Compliant Flex Core And Retractable Wing Skin, Ferruccio Rossi
Design And Evaluation Of A Variable Camber Morphing Wing With Compliant Flex Core And Retractable Wing Skin, Ferruccio Rossi
Theses and Dissertations
Wing morphing was investigated as an alternative to conventional discrete flight control surfaces to provide aircraft attitude control, performance, and to enhance wing aerodynamic efficiency. A variable camber morphing wing design with 100 cm span and 34 cm chord was proposed for small UAVs operated at low velocity. The proposed morphing wing design generated trailing edge deflections via the combined action of an inner complaint flex core structure and a retractable wing skin. Wing morphing was produced by linear servos that extended and retracted the upper and lower wing skin and produced a controlled deformation of the inner complaint flex …
Performance Profile Testing Of The Dassault Falcon 10/100, Thomas Henry Bolek Roman
Performance Profile Testing Of The Dassault Falcon 10/100, Thomas Henry Bolek Roman
Theses and Dissertations
The objective of the performance profile and flight testing comparison is to practice flight test theory on a turbofan-powered aircraft, compare results to Dassault published parameters, and give insight on how this may become a module for the flight test engineering program at Florida Tech. The performance experiments conducted were takeoff performance, level acceleration, level flight performance, stall speed, and roll performance. Takeoff distance was observed using the data from the Stratus ADSB receiver, which gave GPS coordinates; additionally, takeoff distance was measured via Google Earth from the start and the takeoff location observed by the co-pilot. The takeoff field …
Scaling Laws For Fixed-Wing Single-Engine Electric Propulsion Systems, Fnu Hem Lata
Scaling Laws For Fixed-Wing Single-Engine Electric Propulsion Systems, Fnu Hem Lata
Theses and Dissertations
The rise of new aircraft propulsion methods (e.g., powered by batteries, fuel cells, or hybrid electric systems), the increased use of automated and integrated flight control systems, and the envisioned use of personal Vertical Take-off and Landing (VTOL) vehicles in urban environments (urban aerial mobility) lead to novel technical and regulatory challenges for aircraft manufacturers, certification authorities and operators. Of primary concern are operational safety and closely connected pilot situation awareness and workload. The Trajectory Energy Management task involves manipulating flight and propulsion controls to achieve a planned flight profile. The key areas to focus on in Trajectory Energy Management …
Testing And Performance Analysis Of A New Wireless Sensors Network (Wsn) System For Hurricane Monitoring, Jianing Wang
Testing And Performance Analysis Of A New Wireless Sensors Network (Wsn) System For Hurricane Monitoring, Jianing Wang
Theses and Dissertations
Researchers at the Florida Institute of Technology (FIT) have developed the wireless sensor network system for the field measurement of hurricane wind and pressure on residential structures. A new version of the system is developed using the latest state-of-the-art technologies which performance is tested during the passing of hurricane Isaias (2020) and the Wall of Wind (WOW) at Florida International University (FIU). The old version system sensors were applied during hurricane Dorian (2019). For the three events, 25 pressure sensors and one anemometer were placed on the roof of a single-story house. Hurricane Dorian data was collected for 72 hours …