Aerospace Engineering Commons^™

Aerodynamics And Control Of A Deployable Wing Uav For Autonomous Flight, Michael Thamann

Theses and Dissertations--Mechanical and Aerospace Engineering

UAV development and usage has increased dramatically in the last 15 years. In this time frame the potential has been realized for deployable UAVs to the extent that a new class of UAV was defined for these systems. Inflatable wing UAVs provide a unique solution for deployable UAVs because they are highly packable (some collapsing to 5-10% of their deployed volume) and have the potential for the incorporation of wing shaping. In this thesis, aerodynamic coefficients and aileron effectiveness were derived from the equations of motion of aircraft as necessary parameters for autonomous flight. A wind tunnel experiment was performed …

The Allen Telescope Array Search For Electrostatic Discharges On Mars, Marin M. Anderson, Andrew P.V. Siemion, William C. Barott, Geoffery C. Bower, Gregory T. Delory, Imke De Pater, Dan Werthimer

Department of Electrical Engineering and Computer Science - Daytona Beach

The Allen Telescope Array was used to monitor Mars between 2010 March 9 and June 2, over a total of approximately 30 hr, for radio emission indicative of electrostatic discharge. The search was motivated by the report from Ruf et al. of the detection of non-thermal microwave radiation from Mars characterized by peaks in the power spectrum of the kurtosis, or kurtstrum, at 10 Hz, coinciding with a large dust storm event on 2006 June 8. For these observations, we developed a wideband signal processor at the Center for Astronomy Signal Processing and Electronics Research. This 1024 channel spectrometer calculates …

A Systematic Approach For Real-Time Operator Functional State Assessment, Guangfan Zhang, Wei Wang, Aaron Pepe, Roger Xu, Tom Schnell, Nick Anderson, Dean Heitkamp, Jiang Li, Feng Li, Frederick Mckenzie

Electrical & Computer Engineering Faculty Publications

A task overload condition often leads to high stress for an operator, causing performance degradation and possibly disastrous consequences. Just as dangerous, with automated flight systems, an operator may experience a task underload condition (during the en-route flight phase, for example), becoming easily bored and finding it difficult to maintain sustained attention. When an unexpected event occurs, either internal or external to the automated system, the disengaged operator may neglect, misunderstand, or respond slowly/inappropriately to the situation. In this paper, we discuss an approach for Operator Functional State (OFS) monitoring in a typical aviation environment. A systematic ground truth finding …

The Key Ideas Of Mdw Viii: A Summary, Aaron Altman, Clive L. Dym, Ray Hurwitz, John W. Wesner

Mechanical and Aerospace Engineering Faculty Publications

This paper summarizes and highlights the presentations and discussions that took place during Mudd Design Workshop VIII, ‘Design Education: Innovation and Entrepreneurship,’ at Harvey Mudd College. This paper also describes both the key ideas that emerged from the presentations and discussions of the participating engineering design educators, practitioners and researchers, and the methodology used to capture and retain those ideas. Additionally, this paper proposes a framework of design competencies that were created and evolved by the workshop’s participants as a response to a question posed at one of the workshop sessions: ‘What are the minimum design competencies students should learn …

Analysis Of Optimal Control Derivations For Aerial Defense, Andrew John Friedrichs

Masters Theses

"Optimal control will be used to derive four guidance laws for the purpose of defending an aircraft from incoming missiles. The dynamics of the defending missile, and the overall engagement are used in these derivations. They are evaluated first in two degrees of freedom, then in six degrees. The guidance objective is to move a defending missile between the aircraft and the attacker. Optimal control is used to derive different commanded accelerations. Utilizing small changes in the cost functions, four applications will be derived. Triangle Guidance is used for inspiration, and initially a direct approach is attempted. In the course …

Operation Of The Aerodynamic Plasma Actuator At High Altitude, Timothy Glen Nichols

Masters Theses

"A plasma actuator was operated at altitudes from 0 to 18288 meters to determine the mechanisms leading to decreased force production at low pressures. The actuator was driven with a 5 kHz sine wave and a peak to peak voltage of 13.4 kV at pressures of 760, 429, 321, 226, and 88 Torr. A passive measurement technique called the capacitive V-dot probe was adapted to the actuator in order to resolve the spatiotemporal evolution of the surface potential and electric field on the dielectric surface. At low pressures up to 20 times more plasma is present than at atmospheric conditions. …

A Study Of The Integration Of An Inlet Noise Radiation Code With The Aircraft Noise Prediction Program, Devin Kyle Boyle

Masters Theses

"A numerical method has been developed in order to study the effect of turbofan inlet acoustic treatment on the resulting cumulative noise heard by observers on the ground. The approach to creating the tool was to combine the capabilities of the NASA-developed Aircraft Noise Prediction Program (ANOPP) with the fan noise propagation and radiation code developed at Missouri University of Science and Technology. ANOPP can be used to predict the noise metrics resulting from a typical commercial aircraft with turbofan engines on several different flight profiles, including takeoff, approach/landing and a steady (constant altitude/airspeed) flyover. These capabilities are valuable for …

Numerical Investigation Of Second-Law Characteristics Of Ramjet Throttling, Jonathan Albert Sheldon

Masters Theses

"A numerical study of a generic axisymmetric ramjet operating at conditions corresponding to flight Mach 3.0 and a standard altitude of 10 km is presented. The study includes both modeling of steady-state flowfields in the ramjet as well as transient throttling maneuvers in which the throttle is decreased or increased from maximum or minimum throttle positions. The results presented here focus on entropy generation and performance characteristics. Combustion-generated exothermic heat release is modeled using simple volumetric energy addition to the flow within a defined heat release zone. The study utilizes two levels of wall boundary modeling, corresponding respectively to inviscid …

Design And Development Of Ionic Liquid Dual-Mode Spacecraft Propellants, Steven P. Berg

Masters Theses

"Energetic ionic liquids capable of dual-mode chemical monopropellant or bipropellant and electric electrospray rocket propulsion are investigated. Following an extensive literature review, ionic liquids [Bmim][dca], [Bmim][NO₃], and [Emim][EtSO₄] are selected for study since their physical properties align well with the current state-of-the-art in chemical and electrospray propellants. Simulations show that these liquids will not be useful for monopropellant propulsion due to the prediction of solid carbon formation in the exhaust and performance 13-23% below that of hydrazine. Considering these ionic liquids as a fuel component in a binary monopropellant mixture with hydroxyl ammonium nitrate shows 1-4% improved specific impulse over …

Numerical Investigation Of Plasma Actuator Configurations For Flow Separation Control At Multiple Angles Of Attack, Thomas Kelsey West Iv

Masters Theses

"The primary objective of the study presented in this thesis was to analyze the effectiveness of aerodynamic plasma actuators as a means of active flow control over a low speed airfoil at multiple angles of attack each corresponding to two different flow separation mechanisms (i.e., laminar separation bubble and turbulent flow separation at stall conditions). Detailed parametric studies based on steady and unsteady Navier-Stokes simulations, modified to include the body force term created by the plasma actuator, were performed for a NACA 0012 airfoil at a chord Reynolds number of 10⁵. In particular, parametric studies were performed to investigate the …

Gray Gas Analysis Of Radiative Preheating Effects On Shock Induced Combustion, Pratibha Raghunandan

Masters Theses

"The use of detonations in combustors has been receiving increased attention in recent times. The presence of shock waves in such combustors invariably poses the existence of two domains that present different physics for the flow processes. The variation of upstream temperature due to radiative heating by the products of combustion was given particular attention in the present study. The modeling of heat transfer across a normal shock wave of negligible thickness was done by considering the reactants and the products of combustion to be in radiative equilibrium with each other. The quantification of emissivity of the products of combustion …

Studies Of Inductive Plasmas And Their Application To Theta-Pinch Devices Via Numerical Modeling, Warner C. Meeks

Masters Theses

"First, a globally-averaged RF plasma model is used to investigate exit conditions immediately following a RF pre-ionization stage. Analysis shows that reducing pulse duration from 10⁻⁶ to 10⁻⁷ seconds increases peak ion energy fraction by 17% (from 16 to 33%) and doubles final conductivity. Pulse waveforms are square in nature, and ion energy fraction is defined in this work as the percentage of total input energy entrained in ions. Increasing total energy deposition from 5 to 160 mJ increases ion energy fraction from 33% to 58% at a 200 ns pulse duration. This increase is not linear however, showing instead …

Designing Optimal Aviation Baggage Screening Strategies Using The Monkey Search Algorithm, Edgar Ivan Jimenez

Open Access Theses & Dissertations

This thesis addresses the aviation baggage screening design problem considering several baggage screening devices which may be used for system implementation, the devices have different false clear and false alarm rates, throughput and purchase costs. In the present research, a comprehensive cost function which not only includes the cost associated with purchase and operation of baggage security devices, but also includes the indirect costs associated with device errors is used. A new monkey search based evolutionary algorithm is presented to determine the best selection of baggage screening security devices in order to minimize the expected annual total cost. The final …

Measurement And Analysis Of Turbulent Syngas/Air And Methane Oxy-Combustion, Vishwanath Reddy Ardha

Open Access Theses & Dissertations

Development of a next generation gas turbine combustors for power production by using fossil fuels is increasing substantially in order to maintain energy sustainability. National Energy Technology Laboratory has made efforts for developing hydrogen and oxy-fuel based gas turbine combustors which could enhance plant efficiency and ensure low or zero NOx production without sacrificing operational advantages. The current experimental work aims to characterize the turbulent flow-field of premixed syngas/air flames, methane/oxy flames and syngas/oxy flames in a laboratory scaled burner by varying the Reynolds numbers, blockage ratios, firing inputs and blockage ratios in the upstream of the burner. The effects …

Biological Evaluation Of A Novel Tissue Engineering Scaffold Of Layered Double Hydroxides (Ldhs), Fateme Fayyazbakhsh, Mehran Solati-Hashjin, M. A. Shokrgozar, S. Bonakdar, Y. Ganji, N. Mirjordavi, S. A. Ghavimi, P. Khashayar

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Bone Tissue Engineering (BTE) Composed of Three Main Parts: Scaffold, Cells and Signaling Factors. Several Materials and Composites Are Suggested as a Scaffold for BTE. Biocompatibility is One of the Most Important Property of a BTE Scaffold. in This Work Synthesis of a Novel Nanocomposite Including Layered Double Hydroxides (LDH) and Gelatin is Carried Out and its Biological Properties Were Studied. the Co-Precipitation (PH=11) Method Was Used to Prepare the LDH Powder, using Calcium Nitrate, Magesium Nitrate and Aluminum Nitrate Salts as Starting Materials. the Resulted Precipitates Were Dried. X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron …

Thrust Vector Control Of An Upper-Stage Rocket With Multiple Propellant Slosh Modes, Mahmut Reyhanoglu, Jaime Rubio Hervas

Physical Sciences - Daytona Beach

“The thrust vector control problem for an upper-stage rocket with propellant slosh dynamics is considered. The control inputs are defined by the gimbal deflection angle of a main engine and a pitching moment about the center of mass of the spacecraft. The rocket acceleration due to the main engine thrust is assumed to be large enough so that surface tension forces do not significantly affect the propellant motion during main engine burns. A multi-mass-spring model of the sloshing fuel is introduced to represent the prominent sloshing modes. A nonlinear feedback controller is designed to control the translational velocity vector and …

Geographical Assessment Of Microalgae Biofuels Potential Incorporating Resource Availability, Jason C. Quinn, Kimberly Catton, Sara Johnson, Thomas H. Bradley

Mechanical and Aerospace Engineering Faculty Publications

Previous assessments of the economic feasibility and large-scale productivity of microalgae biofuels have not considered the impacts of land and carbon dioxide (CO2) availability on the scalability of microalgae-based biofuels production. To accurately assess the near-term productivity potential of large-scale microalgae biofuel in the US, a geographically realized growth model was used to simulate microalgae lipid yields based on meteorological data. The resulting lipid productivity potential of Nannochloropsis under large-scale cultivation is combined with land and CO2 resource availability illustrating current geographically feasible production sites and corresponding productivity in the US. Baseline results show that CO2 transport constraints will limit …

Large-Eddy Simulation Of Axially-Rotating, Turbulent Pipe And Particle-Laden Swirling Jet Flows, Nicolas D. Castro

Mechanical & Aerospace Engineering Theses & Dissertations

The flows of fully-developed turbulent rotating pipe and particle-laden swirling jet emitted from the pipe into open quiescent atmosphere are investigated numerically using Large-Eddy Simulation (LES). Simulations are performed at various rotation rates and Reynolds numbers, based on bulk velocity and pipe diameter, of 5.3x103, 12x103, and 24x103, respectively. Time-averaged LES results are compared with experimental and simulation data from previous studies. Pipe flow results confirm observations in previous studies, such as the deformation of the turbulent mean axial velocity profile towards the laminar Poiseuille-profile, with increased rotation. The Reynolds stress anisotropy tensor shows a redistribution due to pipe rotation. …

Experimental Investigations Of Pseudospark Discharge And Pseudospark Produced Intense Electron Beams, Jing Hu

Doctoral Dissertations

"This dissertation focuses on the pseudospark discharge, a pulsed discharge discovered for the first time in 1970's. This dissertation is prepared as three journal articles in the style used by Missouri University of Science and Technology. A high voltage pseudospark discharge experiment setup, and discharge and electron beam diagnostic system are constructed and presented in this work. Three journal articles which have been published or are under review are presented in this dissertation on various topics of the pseudospark discharge.

Paper 1 "Experimental investigation of formation time in single-gap pseudospark discharge" is focused on experimental investigations of the time-dependent characteristics …

Object Retrieval From Secure Unknown Interior Spaces Using Autonomous Unmanned Aerial Vehicles, John Levous, Julie Hoven, Victor Habgood, Abdulrahman Alotaibi, Brandon Ordway, Garibe Mohammed-Jones, Haole Guo, Filip Cuckov, Chung-Hao Chen

Electrical & Computer Engineering Faculty Publications

This paper describes an autonomous unmanned aerial vehicle (UAV) designed to participate in the 23rd annual International Aerial Robotics Competition. The UAV is equipped with onboard sensors and a Harvard architecture 8-bit RISC microcontroller to monitor and locally control its flight telemetry. Additional sensors (and an additional microcontroller) are used for detecting and mapping of structural and environmental objects while the UAV is in flight. The microcontrollers are interfaced with wireless communication modules for transmitting flight telemetry and structural/environmental data to a ground control station that sends the UAV command and control signals required for the mission objectives. The UAV …