Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Mechanical Engineering (96)
- Space Vehicles (42)
- Aeronautical Vehicles (37)
- Other Aerospace Engineering (36)
- Aerodynamics and Fluid Mechanics (34)
-
- Structures and Materials (32)
- Propulsion and Power (30)
- Physical Sciences and Mathematics (23)
- Navigation, Guidance, Control and Dynamics (19)
- Systems Engineering and Multidisciplinary Design Optimization (17)
- Electrical and Computer Engineering (15)
- Astrodynamics (13)
- Aviation (8)
- Physics (8)
- Computer Sciences (5)
- Engineering Science and Materials (5)
- Materials Science and Engineering (5)
- Acoustics, Dynamics, and Controls (4)
- Astrophysics and Astronomy (4)
- Heat Transfer, Combustion (4)
- Applied Mechanics (3)
- Arts and Humanities (3)
- Electromagnetics and Photonics (3)
- Operations Research, Systems Engineering and Industrial Engineering (3)
- Other Mechanical Engineering (3)
- Structural Materials (3)
- Applied Statistics (2)
- Aviation Safety and Security (2)
- Institution
-
- California Polytechnic State University, San Luis Obispo (88)
- Air Force Institute of Technology (51)
- University of Kentucky (45)
- University of Texas at Arlington (43)
- Missouri University of Science and Technology (29)
-
- Old Dominion University (22)
- Embry-Riddle Aeronautical University (18)
- University of Alabama in Huntsville (15)
- Morehead State University (14)
- Utah State University (12)
- University of Central Florida (4)
- University of Texas at El Paso (4)
- University of Dayton (3)
- Western Michigan University (3)
- George Fox University (2)
- Minnesota State University, Mankato (2)
- University of Arkansas, Fayetteville (2)
- University of Nebraska - Lincoln (2)
- Wright State University (2)
- Chapman University (1)
- City University of New York (CUNY) (1)
- San Jose State University (1)
- Santa Clara University (1)
- University of Mississippi (1)
- University of Nevada, Las Vegas (1)
- University of New Mexico (1)
- University of South Florida (1)
- Western Kentucky University (1)
- Keyword
-
- #antcenter (9)
- CubeSat (6)
- Turbulence (6)
- Matlab (5)
- Propulsion (5)
-
- Combustion engineering (4)
- Computational fluid dynamics (4)
- UAV (4)
- Ablation (3)
- Aerodynamics (3)
- Aircraft (3)
- Applied sciences (3)
- Composite (3)
- Composites (3)
- Detonation waves (3)
- Fluid dynamics (3)
- Fluid dynamics--Mathematics (3)
- HPH (3)
- Heat Transfer (3)
- Instrumentation (3)
- Manufacturing (3)
- Mathematical optimization (3)
- Micro air vehicles--Design and construction (3)
- Rocket (3)
- Shock (3)
- Simulation (3)
- Spacecraft (3)
- Ablative-Material Response (2)
- Acoustic emission (2)
- Actuators (2)
- Publication
-
- Theses and Dissertations (50)
- Aerospace Engineering (45)
- Master's Theses (38)
- Mechanical and Aerospace Engineering Theses - Archive (37)
- Ablation Workshop (35)
-
- Mechanical and Aerospace Engineering Faculty Research & Creative Works (19)
- Mechanical & Aerospace Engineering Theses & Dissertations (15)
- Von Braun Symposium Student Posters (15)
- Robert "Bob" Twiggs STEM Education Collection (14)
- Doctoral Dissertations and Master's Theses (13)
- All Graduate Theses and Dissertations, Spring 1920 to Summer 2023 (10)
- Masters Theses (10)
- Mechanical Engineering Faculty Publications (6)
- Mechanical and Aerospace Engineering Dissertations - Archive (6)
- Electronic Theses and Dissertations (5)
- Mechanical and Aerospace Engineering Faculty Publications (4)
- Open Access Theses & Dissertations (4)
- Theses and Dissertations--Mechanical and Aerospace Engineering (4)
- Mechanical Engineering (3)
- Aviation Department Publications (2)
- Electrical & Computer Engineering Faculty Publications (2)
- Engineering Management & Systems Engineering Theses & Dissertations (2)
- Faculty Publications - Biomedical, Mechanical, and Civil Engineering (2)
- Graduate Theses and Dissertations (2)
- Mechanical and Materials Engineering Faculty Publications (2)
- The Hilltop Review (2)
- Aerospace Engineering - Daytona Beach (1)
- Art Faculty Articles and Research (1)
- Branch Mathematics and Statistics Faculty and Staff Publications (1)
- Department of Electrical Engineering and Computer Science - Daytona Beach (1)
- Publication Type
- File Type
Articles 331 - 360 of 370
Full-Text Articles in Aerospace Engineering
Numerical Study Of Pressure Fluctuations Due To High-Speed Turbulent Boundary Layers, Lian Duan, Meelan M. Choudhari, Minwei Wu
Numerical Study Of Pressure Fluctuations Due To High-Speed Turbulent Boundary Layers, Lian Duan, Meelan M. Choudhari, Minwei Wu
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Direct numerical simulations (DNS) are used to examine the pressure fluctuations generated by fully developed turbulence in supersonic turbulent boundary layers with an emphasis on both pressure fluctuations at the wall and the acoustic fluctuations radiated into the freestream. The wall and freestream pressure fields are first analyzed for a zero-pressure gradient boundary layer with Mach 2.5 and Reynolds number based on momentum thickness of approximately 2835. The single and multi-point statistics reported include the wall pressure fluctuation intensities, frequency spectra, space-time correlations, and convection velocities. Single and multi-point statistics of surface pressure fluctuations show good agreement with measured data …
Effects Of Riblets On Skin Friction And Heat Transfer In High-Speed Turbulent Boundary Layers, Lian Duan, Meelan M. Choudhari
Effects Of Riblets On Skin Friction And Heat Transfer In High-Speed Turbulent Boundary Layers, Lian Duan, Meelan M. Choudhari
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Direct numerical simulations of spatially developing turbulent boundary layers over riblets are conducted to examine the effects of riblets on skin friction and heat transfer at high speeds. Zero-pressure gradient boundary layers under two flow conditions (Mach 2.5 with Tw/Tr = 1 and Mach 7.2 with Tw/Tr = 0.5) are considered. Simulations are conducted for boundary-layer flows over a clean surface and symmetric V-groove riblets. The DNS results at Mach 2.5 confirm the few existing experimental observations and show that a drag reduction of approximately 7% can be achieved for riblets with proper spacing. The comparisons in turbulence statistics and …
Improving The Efficiency Of Turbocharged Spark Ignition Engines For Passenger Cars Through Waste Heat Recovery, Alberto A. Boretti
Improving The Efficiency Of Turbocharged Spark Ignition Engines For Passenger Cars Through Waste Heat Recovery, Alberto A. Boretti
Mechanical and Aerospace Engineering Faculty Research & Creative Works
The turbocharged direct injection stoichiometric spark ignition gasoline engine has less than Diesel full load brake engine thermal efficiencies and much larger than Diesel penalties in brake engine thermal efficiencies reducing the load by throttling. This engine has however a much better power density, and therefore may operate at much higher BMEP values over driving cycles reducing the fuel economy penalty of the vehicle. This engine also has the advantage of the very well developed three-way catalytic converter after treatment to meet future emission regulations. in these engines the efficiency may be improved recovering the waste heat, but this recovery …
Kers Braking For 2014 F1 Cars, Alberto A. Boretti
Kers Braking For 2014 F1 Cars, Alberto A. Boretti
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Small, high power density turbocharged engines coupled to kinetic energy recovery systems are one of the key areas of development for both passenger and racing cars. in passenger cars, the KERS may reduce the amount of thermal energy needed to reaccelerate the car following a deceleration recovering part of the braking energy. This translates in a first, significant fuel energy saving. Also considering the KERS torque boost increasing the total torque available to accelerate the car, large engines working at very low brake mean effective pressures and efficiencies over driving cycles may also be replaced by small higher power density …
Simulation And Testing Of Polymer Electrolyte Membrane Fuel Cell Bipolar Plates Fabricated By Selective Laser Sintering, M. Wu, Ming-Chuan Leu, N. Guo
Simulation And Testing Of Polymer Electrolyte Membrane Fuel Cell Bipolar Plates Fabricated By Selective Laser Sintering, M. Wu, Ming-Chuan Leu, N. Guo
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Polymer Electrolyte Membrane (PEM) fuel cell converts directly electrochemical energy into electricity. Flow channels in bipolar plates, a critical component of fuel cell, were designed, simulated and tested. the bipolar plate used a mixture of graphite materials and was fabricated using a Selective Laser Sintering (SLS) process. the fabricated green parts were carbonized at high temperatures and converted into brown parts. Infiltration of resin was used to enhance the electric conductivity and strength of the bipolar plate. Finite element simulations were performed to investigate the state of species (hydrogen, oxygen) in the channels and Gas Diffusion Layers (GDLs) for four …
100% Lpg Long Haul Truck Conversion - Economy And Environmental Benefits, Alberto A. Boretti, Charles Grummisch
100% Lpg Long Haul Truck Conversion - Economy And Environmental Benefits, Alberto A. Boretti, Charles Grummisch
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Advanced Vehicle Technologies (AVT), a Ballarat Australia based company, has developed the World's first diesel to 100% LPG conversion for heavy haul trucks. There is no diesel required or utilized on the trucks. the engine is converted with minimal changes into a spark ignition engine with equivalent power and torque of the diesel. the patented technology is now deployed in 2 Mercedes Actros trucks. the power output in engine dynamometer testing exceeds that of the diesel (in excess of 370 kW power and 2700 Nm torque). in on-road application the power curve is matched to the diesel specifications to avoid …
Design Of Rankine Cycle Systems To Deliver Fuel Economy Benefits Over Cold Start Driving Cycles, Alberto A. Boretti, Azmi Osman, Ishak Aris
Design Of Rankine Cycle Systems To Deliver Fuel Economy Benefits Over Cold Start Driving Cycles, Alberto A. Boretti, Azmi Osman, Ishak Aris
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Prior papers have shown the potentials of gasoline-like internal combustion engines fitted with waste heat recovery systems (WHR) to deliver Diesel-like steady state fuel conversion efficiencies recovering the exhaust and the coolant waste heat with off-the-shelf components. in addition to the pros of the technology significantly increasing steady state efficiencies - up to 5 % in absolute values and much more in relative values - these papers also mentioned the cons of the technology, increased back pressures, increased weight, more complex packaging, more complex control, troublesome transient operation, and finally the cold start issues that prevent the uptake of the …
Inherent And Model-Form Uncertainty Analysis For Cfd Simulation Of Synthetic Jet Actuators, Daoru Frank Han, Serhat Hosder
Inherent And Model-Form Uncertainty Analysis For Cfd Simulation Of Synthetic Jet Actuators, Daoru Frank Han, Serhat Hosder
Mechanical and Aerospace Engineering Faculty Research & Creative Works
A mixed (aleatory and epistemic) uncertainty quantification (UQ) method was applied to computational uid dynamics (CFD) modeling of a synthetic jet actuator. A test case, (ow over a hump model with synthetic jet actuator control) from the CFDVAL2004 work-shop was selected to apply the Second-Order Probability framework implemented with a stochastic response surface obtained from Quadrature-Based Non-Intrusive Polynomial Chaos (NIPC). Three uncertainty sources were considered: (1) epistemic (model-form) uncertainty in turbulence model, (2) aleatory (inherent) uncertainty in free stream veloc-ity and (3) aleatory uncertainty in actuation frequency. Uncertainties in both long-time averaged and phase averaged quantities were quantified using a …
Evaluation Of Niobium As Candidate Electrode Material For Dc High Voltage Photoelectron Guns, Mahzad Bastaninejad, Md. Abdulla Mohamed, Abdelmageed Elmustafa, P. Adderley, J. Clark, S. Covert, J. Hansknecht, C. Hernandez-Garcia, M. Poelker, R. Mammei, K. Surles-Law, P. Williams
Evaluation Of Niobium As Candidate Electrode Material For Dc High Voltage Photoelectron Guns, Mahzad Bastaninejad, Md. Abdulla Mohamed, Abdelmageed Elmustafa, P. Adderley, J. Clark, S. Covert, J. Hansknecht, C. Hernandez-Garcia, M. Poelker, R. Mammei, K. Surles-Law, P. Williams
Mechanical & Aerospace Engineering Faculty Publications
The field emission characteristics of niobium electrodes were compared to those of stainless steel electrodes using a DC high voltage field emission test apparatus. A total of eight electrodes were evaluated: two 304 stainless steel electrodes polished to mirrorlike finish with diamond grit and six niobium electrodes (two single-crystal, two large-grain, and two fine-grain) that were chemically polished using a buffered-chemical acid solution. Upon the first application of high voltage, the best large-grain and single-crystal niobium electrodes performed better than the best stainless steel electrodes, exhibiting less field emission at comparable voltage and field strength. In all cases, field emission …
Instrumentation, Control And Torch Ignition Systems Development For Lox/Methane Propulsion Research, Jesus Betancourt-Roque
Instrumentation, Control And Torch Ignition Systems Development For Lox/Methane Propulsion Research, Jesus Betancourt-Roque
Open Access Theses & Dissertations
A liquid propulsion research facility has been developed at the Center for Space Exploration Technology Research at The University of Texas at El Paso. This facility has capabilities for producing up to 25 liters of Liquid Methane, feeding LOX/Methane propellants to 100 N class thrusters and conducting automated steady state and pulsing combustion experiments. This work describes the design, development and testing process of the Data Acquisition and Remote Control System developed to integrate an Altitude Simulation System, a Cryogenic Delivery System, and multiple rocket combustors and thrusters. A Torch Ignition System development is detailed as well as the evaluation …
Cryogenic System Development For Lox/ Hydrocarbon Propulsion Research, Francisco Pineda
Cryogenic System Development For Lox/ Hydrocarbon Propulsion Research, Francisco Pineda
Open Access Theses & Dissertations
A propulsion research facility is being developed at the Center for Space Exploration Technology Research (cSETR) at the University of Texas at El Paso (UTEP). These facilities were developed in order to meet new research demand for Liquid Oxygen (LOX)/Liquid methane (LCH4) experiments. The main goal of this system is to produce in-house liquid methane and supply propellants to their respective test set up in a cryogenic state. The work presented describes the design, development, and operation of a liquid methane condensation system and a cryogenic delivery feed system. The condensation system design will allow for a production of methane …
Development Of Detailed Computational Flow Model Of High End Server And Validation Using Experimental Methods, Vijayalayan Pandiyan
Development Of Detailed Computational Flow Model Of High End Server And Validation Using Experimental Methods, Vijayalayan Pandiyan
Mechanical and Aerospace Engineering Theses - Archive
The continued development of the microprocessor has led to significant increase in high frequency interconnects and power dissipation. High power devices are pushing the limits of air cooling in data center environments. Data center power consumption continues to grow at a rapid pace. In light of this increasing trend in power consumption, computer systems researchers, application designers, power and cooling engineers, and governmental bodies have all launched research efforts to improve data center energy efficiency [1]. Rack servers tend to be the main perpetrators of wasting energy and represent the largest portion of the IT energy load in a typical …
Experimental/Computational Analysis Of Active Cooling Of Stacked Device Using Multidimensional Configured Thermoelectric Modules, Vaidehi Bharat Patel
Experimental/Computational Analysis Of Active Cooling Of Stacked Device Using Multidimensional Configured Thermoelectric Modules, Vaidehi Bharat Patel
Mechanical and Aerospace Engineering Theses - Archive
Stacked devices are currently used widely because of their smaller footprint and corresponding ability to accommodate heterogeneous devices such as memory and logic and enable a silicon efficiency greater than 100%. This configuration will results in thermal management challenges due to the torturous heat dissipation path. In addition, the non-uniformity in chip power distribution results in an increased spreading resistance as well as temperature gradient at the device level that can degrade performance and reliability. In this study the Thermoelectric Modules were configured in a multidimensional form surrounding a three dimensional cold core. The corresponding Computational Fluid Dynamics model is …
Large Scale Finite Element Analysis Using Gpu Parallel Computing, Ashkan Akbariyeh
Large Scale Finite Element Analysis Using Gpu Parallel Computing, Ashkan Akbariyeh
Mechanical and Aerospace Engineering Theses - Archive
In the past years, graphic processing units have become a new abundant parallelcomputing resource on personal computers. In this work parallel computation ofa typical case in nite element analysis for solids has been practiced. The solutionof 3-D linear elastic static problems with 3 degree of freedom is fully implementedutilizing the current GPU technology. Discretization of the problem has been donefor two cases of: Tetrahedral and Hexahedral elements. Acceleration of the solutionhas been realized using SIMT parallel algorithms. Sparse matrix storage formats aswell as matrix-vector operations are investigated for optimum hardware utilization.preconditioned conjugate gradient method has been fully implemented on the …
Protection Of Humanity’S Cultural And Historic Heritage In Space, Justin St. P. Walsh
Protection Of Humanity’S Cultural And Historic Heritage In Space, Justin St. P. Walsh
Art Faculty Articles and Research
While the international community has acted forcefully since World War II to protect sites and objects of cultural or historic significance on Earth, little attention has been paid to the same kinds of sites and objects in space. There are important ethical and scholarly reasons for wanting to preserve sites and in situ objects in off-Earth contexts from destruction or commercial exploitation. Innovative space research equipment, such as spacecraft, satellites, and space stations, and the locations of historic missions, such as Tranquility Base, therefore deserve formal international recognition and protection. Appropriate models for developing a comprehensive protective scheme can be …
Thermal Stability Characteristics Of Fisher-Tropsch And Hydroprocessed Alternative Aviation Fuels In A Fixed Bed Reactor, Sergio Quintero
Thermal Stability Characteristics Of Fisher-Tropsch And Hydroprocessed Alternative Aviation Fuels In A Fixed Bed Reactor, Sergio Quintero
Electronic Theses and Dissertations
Growing prices, limited supply, and public concern about greenhouse gases associated with crude-derived jet fuels have led to development of renewable alternatives which must be compatible with the worldwide civilian and military aviation infrastructure, which were designed for operation with Jet-A/JP-8. Any alternative fuel should not have negative effects on the aircraft engines and fuel systems, especially from a thermal stability perspective, since any adverse effect of the physical properties, and chemical composition, including existence of trace elements, of those fuels may only be revealed after extensive operation, resulting in higher life-cycle maintenance and operation costs. This study considered four …
A Filter-Forcing Turbulence Model For Large Eddy Simulation Incorporating The Compressible "Poor Man's" Navier--Stokes Equations, Joshua Strodtbeck
A Filter-Forcing Turbulence Model For Large Eddy Simulation Incorporating The Compressible "Poor Man's" Navier--Stokes Equations, Joshua Strodtbeck
Theses and Dissertations--Mechanical and Aerospace Engineering
A new approach to large-eddy simulation (LES) based on the use of explicit spatial filtering combined with backscatter forcing is presented. The forcing uses a discrete dynamical system (DDS) called the compressible ``poor man's'' Navier--Stokes (CPMNS) equations. This DDS is derived from the governing equations and is shown to exhibit good spectral and dynamical properties for use in a turbulence model. An overview and critique of existing turbulence theory and turbulence models is given. A comprehensive theoretical case is presented arguing that traditional LES equations contain unresolved scales in terms generally thought to be resolved, and that this can only …
Design And Flight Testing Of A Warping Wing For Autonomous Flight Control, Edward Brady Doepke
Design And Flight Testing Of A Warping Wing For Autonomous Flight Control, Edward Brady Doepke
Theses and Dissertations--Mechanical and Aerospace Engineering
Inflatable-wing Unmanned Aerial Vehicles (UAVs) have the ability to be packed in a fraction of their deployed volume. This makes them ideal for many deployable UAV designs, but inflatable wings can be flexible and don’t have conventional control surfaces. This thesis will investigate the use of wing warping as a means of autonomous control for inflatable wings. Due to complexities associated with manufacturing inflatable structures a new method of rapid prototyping deformable wings is used in place of inflatables to decrease cost and design-cycle time. A UAV testbed was developed and integrated with the warping wings and flown in a …
Low Reynolds Number Flow Field Modification Via Travelling Wave Actuation Of A Vertically Aligned Wire Array Surface, John C. Calhoun
Low Reynolds Number Flow Field Modification Via Travelling Wave Actuation Of A Vertically Aligned Wire Array Surface, John C. Calhoun
Theses and Dissertations--Mechanical and Aerospace Engineering
Experiments were conducted to observe the effects of an active wire surface on low-Reynolds number Poiseuille flow. The objective was to evaluate the feasibility of actuating piezoelectric nanowires into a travelling wave motion in order to reduce wall shear stress in turbulent flows. Studies have shown that travelling wave motions introduced into the bounding wall of turbulent flow can reduce wall shear stress by disrupting the formation of drag-inducing coherent vortical structures. A Reynolds number scaled flow facility was designed to represent the near-wall region of turbulent flow. A wire surface was installed in the bounding wall and dynamically actuated …
Aerodynamics And Control Of A Deployable Wing Uav For Autonomous Flight, Michael Thamann
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
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
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
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
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
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
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
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
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
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
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 …