Engineering Commons^™

Dynamic Response Of A Hingeless Helicopter Rotor Blade At Hovering And Forward Flights, Pratik Sarker

University of New Orleans Theses and Dissertations

The helicopter possesses the unrivaled capacity for vertical takeoff and landing which has made the helicopter suitable for numerous tasks such as carrying passengers and equipment, providing air medical services, firefighting, and other military and civil tasks. The nature of the aerodynamic environment surrounding the helicopter gives rise to a significant amount of vibration to its whole body. Among different sources of vibrations, the main rotor blade is the major contributor. The dynamic characteristics of the hingeless rotor consisting of elastic blades are of particular interest because of the strongly coupled equations of motion. The elastic rotor blades are subjected …

Operating Different Displays In Military Fast Jets Using Eye Gaze Tracker, Jeevitha Shree Dv, L. R. D. Murthy, Kamalpreet Singh Saluja, Pradipta Biswas

Journal of Aviation Technology and Engineering

This paper investigated the use of an eye-gaze-controlled interface in a military aviation environment. We set up a flight simulator and used the gaze-controlled interface in three different configurations of displays (head down, head up, and head mounted) for military fast jets. Our studies found that the gaze-controlled interface statistically significantly increased the speed of interaction for secondary mission control tasks compared to touchscreen- and joystick-based target designation system. Finally, we tested a gaze-controlled system inside an aircraft both on the ground and in different phases of flight with military pilots. Results showed that they could undertake representative pointing and …

Cfd Modeling Of Smoke Movement In An Atrium, Robin Wu

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this paper is to better understand the behavior of smoke movement in an atrium. Thus gives first responders and civilians in and out of building a better understanding

With the advancements of modern technology, computers and softwares make simulation models possible such as fire models to simulate fire and smoke movements. In this paper, a computational fluid dynamic (CFD) software Fire Dynamic Simulator (FDS) is used to conduct a series of atrium tests to investigate the effectiveness of smoke exhaust systems. FDS solves the Navier-Stokes equations appropriate for low speed flows (Ma < 0.3) with an emphasis on smoke, heat transport and CO2 concentrations from fires. The default turbulence model used in FDS simulation is the Large Eddy Simulation (LES), which is the solution of Navier-Stokes equations at low speed.

The compartment tested was 9 …

Effects Of Secondary Stall And Unsteady Free-Stream On Blade Drag And Pitching Moments, Michael Malick

McKelvey School of Engineering Theses & Dissertations

Dynamic stall is a complex aerodynamic phenomenon occurring in helicopter rotors, limiting the flight envelope and causing control linkage damage and instabilities. The Peters-Modarres semi-empirical dynamic stall model is extended to simulate pitching moment and drag in unsteady freestream and yawed flow, including the effects of secondary stall. The aerodynamics are implemented as a state-space model, suitable for time-marching or aeroelastic analyses. With small modifications to the original stall model, secondary stall effects and unsteady freestream can be simulated without adding additional states. An optimization routine determines sets of parameters that minimize the error between the modeled solution and experimental …

Effects Of Secondary Stall And Unsteady Free-Stream On Blade Drag And Pitching Moments, Michael Malick

McKelvey School of Engineering Theses & Dissertations

Dynamic stall is a complex aerodynamic phenomenon occurring in helicopter rotors, limiting the flight envelope and causing control linkage damage and instabilities. The Peters-Modarres semi-empirical dynamic stall model is extended to simulate pitching moment and drag in unsteady freestream and yawed flow, including the effects of secondary stall. The aerodynamics are implemented as a state-space model, suitable for time-marching or aeroelastic analyses. With small modifications to the original stall model, secondary stall effects and unsteady freestream can be simulated without adding additional states. An optimization routine determines sets of parameters that minimize the error between the modeled solution and experimental …

Fundamentals Of Aerospace Engineering, Manny Pacquiao

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Rotating Mount For Complex Fluid Flow Research, Kirsten Murphy

Honors Theses

Fluid flow around rotating objects is mathematically complex and there is currently limited experimental data on the subject. To make Western Michigan University capable of this research, a rotating wind tunnel mount was developed. The mount design was integrated into the existing setup at the Applied Aerodynamics Laboratory (AAL) to allow seamless transitions between different research projects. Non-rotating and rotating disk prototypes were created from 3D-printed materials to test the mount’s capabilities. Experimental data gathered from utilizing this rotating mount was analyzed to understand the aerodynamic effects on rotating disks in a fluid stream. From testing the rotating disk prototype …

Rotating Mount For Complex Fluid Flow Research, Kirsten Murphy

Honors Theses

Fluid flow around rotating objects is mathematically complex and there is currently limited experimental data on the subject. To make Western Michigan University capable of this research, a rotating wind tunnel mount was developed. The mount design was integrated into the existing setup at the Applied Aerodynamics Laboratory (AAL) to allow seamless transitions between different research projects. Non-rotating and rotating disk prototypes were created from 3D-printed materials to test the mount’s capabilities. Experimental data gathered from utilizing this rotating mount was analyzed to understand the aerodynamic effects on rotating disks in a fluid stream. From testing the rotating disk prototype …

Ultraviolet Imager Application For A Cube Satellite, Jason Grillo, Troy Hajjar, Brady Hill

Mechanical Engineering

This document serves as the final design review (FDR) report for the 2018 Cal Poly CubeSat Ultraviolet Imager senior project, sponsored by UC Berkeley Space Sciences Laboratories (SSL). SSL wants to monitor the ionosphere above Earth to gain a better understanding of its properties and particle interactions. Far Ultraviolet (FUV) imaging is a good way to obtain high quality images of the ionosphere and the Earth's auroras, and advancement in optic technologies have made cube satellites (CubeSats) an ideal vessel for a FUV imager, as they are relatively low-cost, lightweight, and can be repeatedly deployed. These CubeSat FUV imagers could …

Flight Vehicle Design, Andrew Ning

Books

No abstract provided.

Inter-Laminar Fracture Of 3d-Printed Plastics - Development Of Methods, Christopher Stolinski

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Due to the increased use of 3D printed acrylonitrile butadiene styrene (ABS) plastic parts, a way to quantify the failure energy (energy needed to initiate cracking) is needed. Impact tests at high rates of loading are performed to determine failure energy. Throughout testing, specimens are monitored with high speed cameras to perform camera-based deformation measurements. Data acquisition and processing methods to calculate failure energy using crack opening displacement, and loading rates are developed to enable further use by Dr. Ryan Berke’s lab at Utah State University.

Finite Element Modeling And Experimental Characterization Of Knot Configuration Effect On The Mechanical Performance Of Surgical Suture, Arz Y. Qwam Alden

Dissertations

Tendon injuries in orthopedic surgery and sports medicine are escalating; hence there is great interest in improving tendon repair. The integrity of tendon repair depends in part on a combination of suture material, suture size and knot configuration. Recent studies have indicated the failure of surgical knots as a failure mode during surgical repair. Further, there is still no consensus on the ideal (best/safest) surgical knot techniques. Also, this failure mode is related to stress concentrations, which cannot be easily established with traditional tensile testing. Most researchers have focused on the measurement and comparison of the gross structural response of …

Experimental Investigation Of A Green Hybrid Thruster Using A Moderately Enriched Compressed Air As The Oxidizer, Marc Anthony Bulcher

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A hybrid rocket is a propulsion system that uses propellants in two different phases, typically a solid fuel inside the combustion chamber and a separate gaseous or liquid oxidizer stored in a tank. Hybrid rockets are an area of research interest because of their low explosive risk, inexpensive components, and high degree of reliability. In the Propulsion Research Laboratory at Utah State University, pure oxygen is among the top choice for hybrid rocket oxidizers due to its low cost and ease of storage. When paired with a solid fuel known as ABS (acrylonitrile butadiene styrene) plastic, specific impulse values exceed …

Autonomous Trajectory Planning For Satellite Rpo And Safety Of Flight Using Convex Optimization, Nicholas G. Ortolano

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Optimal trajectory planning methods that implement convex optimization techniques are applied to the area of satellite rendezvous and proximity operations. This involves the development of linearized relative orbital motion dynamics and constraints for two satellites, where one maintains a near-circular reference orbit. The result is formulated as a convex optimization problem, where the objective is to minimize the amount of fuel required to transfer from a given initial condition to the desired final conditions. A traditional rendezvous and proximity operations scenario is analyzed, which includes examples of initial approach, inspection, final approach, and docking trajectories. This scenario may include trajectory …

Design Of An Attitude Control System For A Spacecraft With Propellant Slosh Dynamics, Nolan Coulter

Doctoral Dissertations and Master's Theses

The presence of propellant slosh dynamics in a spacecraft system during a maneuver leads to attitude control system (ACS) performance degradation resulting in attitude tracking errors and instability. As spacecraft missions become more complex and involve longer durations, a substantial propellant mass is required to achieve the mission objectives and perform orbital maneuvers. When the propellant tanks are only partially filled, the liquid fuel moves inside the tanks with translational and rotational accelerations generating the slosh dynamics. This research effort performs a comparative study with different optimal control techniques and a novel application of a model reference artificial immune system …

Design And Implementation Of Intelligent Guidance Algorithms For Uav Mission Protection, Karina Rivera

Doctoral Dissertations and Master's Theses

In recent years, the interest of investigating intelligent systems for Unmanned Aerial Vehicles (UAVs) have increased in popularity due to their large range of capabilities such as on-line obstacle avoidance, autonomy, search and rescue, fast prototyping and integration in the National Air Space (NAS). Many research efforts currently focus on system robustness against uncertainties but do not consider the probability of readjusting tasks based on the remaining resources to successfully complete the mission. In this thesis, an intelligent algorithm approach is proposed along with decision-making capabilities to enhance UAVs post-failure performance. This intelligent algorithm integrates a set of path planning …

Control Driven Scaling Effects Of Motor And Rotors For Urban Air Mobility Design, Agustin A. Giovagnoli

Doctoral Dissertations and Master's Theses

Through this thesis research the problem of controllability and propulsion associated with scaling-up consumer drones to vehicles that may carry significantly larger payloads, including passenger will be analyzed and tested. Controllability is mainly compromised due to the increasing response time of a larger rpm controlled rotor. This requires a more powerful motor, which translates into heavier and larger devices compromising the thrust-to-weight ratio. Collective pitch control at constant rpm is proposed as a first approach to mitigate the controllability problem, and it is tested in a MATLAB Simulink environment. This solution, linked to a Non-linear Dynamic Inversion controller, is simulated …

Quantitative Measurement Techniques For Vibration And Buffet, Edward Thomas Meyer

Theses and Dissertations

This paper outlines a proposed parameter for measurement of vibration and buffet in vehicles. It is intended to be used where applicable in lieu of raw accelerometer data or qualitative comments to measure ride quality, quantify vibration levels, and aid in certification matters. In flight vehicle applications which employ fly-by wire flight control systems with closed loop and variable gain control laws, the phenomenon of buffet in its various forms is becoming somewhat specious as an aircrew cue in relation to the stability and control of flight vehicles. In these applications, stability and control throughout the operating envelope is designed …

Comparative Analysis Of Electrodynamic Toroidal Radiation Shielding Configurations, Max Rosenberg

Master's Theses

Beyond the protective confines of Earth's atmosphere and magnetosphere, spacecraft are subject to constant bombardment by high-energy charged particles originating from our Sun in the form of Solar Particle Events (SPEs), and from outside the solar system in the form of Galactic Cosmic Rays (GCRs). The harm these particles do can be reduced or mitigated outright through radiation shielding. Because protons and other charged particles comprise most of these radiation particles, strong magnetic fields could be generated around spacecraft to deflect incoming charged radiation particles. This thesis investigates the performance of specific configurations of toroidal superconducting solenoids to generate magnetic …

Development Of Adaptable Human-Machine Interface For Teleoperation Over Time Delay, May Nyein Chan

Theses and Dissertations

The Adaptable Human-Machine Interface (AHMI) was developed for the Orbital Robotic Interaction, On-orbit servicing, and Navigation (ORION) Laboratory of the Florida Institute of Technology. The primary project objective was to develop and test a predictive display for mitigating the effects of time delay in teleoperation of space robots and Unmanned Aerial Vehicles (UAV) using quadcopters as a test case. Regardless of the increasing popularity of various autonomous systems, research and development of teleoperating system should not be neglected since it is often utilized as a back-up in most autonomous systems especially in systems for human spaceflight and UAV operations in …

Carbon Nanotube Fibers: Mechanical Behavior And The Effects Of The Space Environment, Ryan A. Kemnitz

Theses and Dissertations

Carbon nanotube materials are promising multifunctional materials for incorporation into aerospace structures because of their high tensile strength, high electrical conductivity, and low density. This research aimed to characterize the mechanical failure mechanisms of carbon nanotube fibers and examine the effects of the space environment on their material properties. Tensile tests were conducted at varying strain rates and on fibers of varying gage lengths to examine the underlying molecular failure mechanisms and impact of defects on fiber strength. Tensile strength and elastic modulus were observed to increase with increasing strain rate and decrease with increasing gage lengths. The observed effects …

Thermal Management Of Satellite Electronics Via Gallium Phase Change Heat Sink Devices, Brian O. Palmer

Theses and Dissertations

The purpose of this research was to determine the effectiveness and feasibility of additively manufactured heat sinks using gallium as a phase change material in the thermal management of satellite electronics. A design was created based on the footprint of an Astronautical Development, LLC Lithium 1 UHF radio and six heat sinks were additively manufactured; two each of stainless steel 316, Inconel 718, and ULTEM 9085. Each heat sink was filled with gallium for testing purposes. Models were created to simulate the behavior of the heat transfer and phase change processes occurring within the heat sink. Additionally, laboratory data was …

Experimental And Computational Analysis Of The Interaction Of Carbon And Silicon Ablation Products In Expanding Hypersonic Flows, Brian E. Donegan

Theses and Dissertations

Thermal protection is required for vehicles entering planetary atmospheres to protect against the severe heating loads experienced. Characterization of candidate materials is often done utilizing plasma or arc-jet facilities, which provide steady-state testing of the thermal environments experienced during hypersonic flight, but do not correctly simulate hypersonic flowfields. Conversely, impulse facilities can reproduce flight velocities and enthalpies but have extremely short test times, prohibiting testing of thermal response. Modeling ablation and heating rates, particularly in the wake region, remains a significant challenge due to the complexity of the flowfield. To better understand this complex phenomenon and provide data to validate …

Free Response And Trim Force Requirements For Aircraft Configuration Changes, Marvin Toepfer

Theses and Dissertations

As an FAA Commercial Pilot and Flight Instructor, one comes in contact with many different types of experiences and abnormal situations. A widely known cause of fatal accidents in the general aviation industry, and also currently listed on the National Transportation Safety Board Most Wanted List, is the loss of control in the traffic pattern [1]. For many years now, different departments of the FAA and Department of Transportation, such as the FAA Small Airplane Directorate, have been trying to mitigate the risks and causes associated with the loss of control in the traffic pattern. Due to technological advancements and …

Aerodynamic Model Of The Piper Warrior Ii Based On Flight Test Data, Nicholas Casciola

Theses and Dissertations

Aerodynamic modeling is an important part of aircraft design and of aircraft testing. Generally, this is done through CFD models and Wind Tunnel tests prior to the aircrafts first flight but building the models using flight test data is also very important. It is used to verify theoretical models generated from the computer and wind tunnel tests. They are also useful for building simulators, particularly those in modeling and analyzing airport traffic patterns. These tests used a Piper Pa-28-161 Warrior II owned by the Florida Tech Flight Test Engineering program. It has a 160hp Lycoming engine. The test pilot was …

Effect Of Film Cooling Hole Size On A Turbine Rotor Blade, Klint Martis

Theses and Dissertations

The objective of this study was to evaluate the effect of the cooling hole size on the adiabatic film cooling effectiveness over a rotating turbine blade section. The study was conducted using ANSYS FLUENT to determine the adiabatic wall temperature over the blade surface. The geometry was created to be a single section of a turbine rotating at 4000 rpm, and the blade increases in camber from tip to hub. Cylindrical cooling holes were created and the diameters were varied from 0.5 mm to 1.5 mm. The pitch-to-diameter ratio and the length-to-diameter ratio were kept constant at a value of …

Control Development For Autonomous Landing Of Quadcopter On Moving Platform, Rakhayai Mangsatabam

Theses and Dissertations

This thesis focuses on the control development for autonomous landing of a quadcopter on a moving platform. The object tracking and path following is performed through on-board vision-based systems. The goal of the thesis is to develop a controller for autonomous landing of a quadcopter and test its fidelity with simulations and experiments. The thesis is carried out in two sections, simulation and experiment. The simulation was carried out based on the system modeled and a PD (Proportional Derivative) controller was used to simulate the quadcopter landing. The simulation was split into three parts, with each part attempting to become …

Cubesat Docking And Resource Sharing Mechanism, Shingo Kunito

Theses and Dissertations

This thesis addresses the design concept of a CubeSat docking and resource sharing mechanism that allows to transfer propellant that is pressurized gas, data, and power. In docking and capture design, the interface is equipped with two air cylinders that are rated up to 20.68 MPa internal pressure generating the ideal force of 1218.4 N each. With the designed air cylinder and mounted configuration, the maximum capture distance between the target and the chaser CubeSat is 40.30 mm. Since air cylinder and body frame are designed specifically for this interface, structural analysis was conducted in ANSYS where results show a …

Additively-Manufactured Hybrid Rocket Consumable Structure For Cubesat Propulsion, Britany L. Chamberlain

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Three-dimensional, additive printing has emerged as an exciting new technology for the design and manufacture of small spacecraft systems. Using 3-D printed thermoplastic materials, hybrid rocket fuel grains can be printed with nearly any cross-sectional shape, and embedded cavities are easily achieved. Applying this technology to print fuel materials directly into a CubeSat frame results in an efficient, cost-effective alternative to existing CubeSat propulsion systems. Different 3-D printed materials and geometries were evaluated for their performance as propellants and as structural elements. Prototype "thrust columns" with embedded fuel ports were printed from a combination of acrylonitrile utadiene styrene (ABS) and …