Open Access. Powered by Scholars. Published by Universities.®

Aerospace Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

2019

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 421 - 450 of 458

Full-Text Articles in Aerospace Engineering

The Design And Testing Of A 500 Lbf Liquid Oxygen/Liquid Methane Engine, Manuel Jesus Herrera Jan 2019

The Design And Testing Of A 500 Lbf Liquid Oxygen/Liquid Methane Engine, Manuel Jesus Herrera

Open Access Theses & Dissertations

The development of liquid oxygen/liquid methane (LOX/LCH4) propulsion systems has recently become a topic of interest ever since this particular propellant combination was determined to be a suitable candidate for use in space exploration, more specifically missions to Mars. This propellant combination is unique because the propellants can be synthesized from local resources on Mars, a process called In-situ Resource Utilization (ISRU). ISRU would allow for spacecrafts to be lighter and/or increase its payload capacity to Mars-bound missions because the vehicle would not have to store the propellants required for the voyage back to earth.

For this reason, The University …


Small Satellite Development At Utep, Emily Herzog Jan 2019

Small Satellite Development At Utep, Emily Herzog

Open Access Theses & Dissertations

The small satellite industry has seen tremendous growth in recent years. A CubeSat is a particular type of standardized small satellite that follows the CubeSat specifications. These specifications define the structural, testing, and operational requirements of the satellite. This standard facilitates cheaper design, integration, and launch of satellites, allowing smaller organizations to participate in the normally costly area of space exploration.

The University of Texas at El Paso has recognized the opportunity and has begun developing several CubeSats. The two that are the topic of this Thesis are called Orbital Factory II (OFII) and Orbital Factory X (OFX). An on-orbit …


Structures And Daq System For The Lox/Lch4 500 And 2000 Lbf. Rocket Engines, Rachel Pilgrim Jan 2019

Structures And Daq System For The Lox/Lch4 500 And 2000 Lbf. Rocket Engines, Rachel Pilgrim

Open Access Theses & Dissertations

With the progression of space exploration and research, new alternative fuels and fuel combinations have been discovered. The ability to produce methane from Mars' atmosphere and oxygen from Mars' regolith has led to the two becoming a great alternative propellant combination for rocket propulsion systems. To further advance LOX/LCH4 propulsion systems, a 500 and 2000 lbf rocket engine were designed and manufactured and are to be launched from the MIRO cSETR Technology Research and Innovation Acceleration Park (tRIAc) in Fabens, Texas for data collection and analysis. The objective of this thesis is to give a thorough overview of the static …


Thermal/Mechanical Analysis And Development Of A 2000 Lbf Liquid Oxygen/Liquid Methane Rocket Engine, Marissa Garcia Jan 2019

Thermal/Mechanical Analysis And Development Of A 2000 Lbf Liquid Oxygen/Liquid Methane Rocket Engine, Marissa Garcia

Open Access Theses & Dissertations

The Center for Space Exploration and Technology Research (cSETR) is developing three rocket engines: a 5 lbf reaction control engine, a 500 lbf engine, and a 2000 lbf engine. All these engines utilize a liquid oxygen and liquid methane propellant combination. The reason methane was selected for the fuel is because methane is easy to store, is self-pressurizing, and readily available. There is also the possibility of creating methane on planets such as Mars through an electrolysis process on the ice water found on Mars.

The 2000 lbf engine, or the CROME-X, is a modular, steady-state pintle injector engine. It …


Investigating Using Titanium Zirconium Molybdenum For Additively Manufacturing Aerospace Components, Justin Hunter Vanhoose Jan 2019

Investigating Using Titanium Zirconium Molybdenum For Additively Manufacturing Aerospace Components, Justin Hunter Vanhoose

Open Access Theses & Dissertations

Mankind throughout history has possessed an innate characteristic to explore, migrating to new frontiers.The requirement for this travel is most broadly associated with the need to pursue more resources. Rockets have been used as a means of weapons since the Sung Dynasty in the thirteenth empire and have now been integrated for travel/transport. The sophistication of rocketry and propulsion has reached a level to where it is plausible that mankind will be a multi-planetary species. The space industry has grown significantly with the advancement of the sophistication of these rocket technologies. However, a specific challenge to overcome in the space …


Structural Design Of Complex Components, Armando Antonio Ochoa Jan 2019

Structural Design Of Complex Components, Armando Antonio Ochoa

Open Access Theses & Dissertations

The University of Texas at El Paso (UTEP) and the Center for Space Exploration and Technology Research (cSETR) is determined to develop a launch vehicle that is made completely of additive manufacturing materials, has the capability to transport a 100 lb payload to low earth orbit (LEO) as well as completing the design of a strucutral steel mobile launch stand that has the capability of withstanding the launch vehicle's static and dynamic loadings. The project will consist of carbon composite components to reduce weight while maintaining efficiency, strucutral steel components to resist extreme loadings and maintain strucutral shape, and lastly …


Ultrafine Aluminium: Quench Collection Of Agglomerates, Tejasvi K, Y Pydi Setty, Vemana Venkateswara Rao Jan 2019

Ultrafine Aluminium: Quench Collection Of Agglomerates, Tejasvi K, Y Pydi Setty, Vemana Venkateswara Rao

International Journal of Aviation, Aeronautics, and Aerospace

Combustion of aluminized solid propellants exhibits phenomena associated with accumulation, agglomeration, ignition, and combustion of ultra-fine aluminium particles. In this study, agglomeration phenomenon of ultra-fine aluminium in solid propellant combustion is investigated using quench collection experimental technique over the pressure ranges from 2MPa to 8MPa. The ultra-fine aluminium powder synthesized by Radio Frequency Induction Plasma technique having harmonic mean size of 438nm is used for agglomeration study. The quenching distance is varied from 5mm to 71mm from the propellant burning surface to estimate the effect on agglomerate size. The morphology and chemical compositions of the collected products were then studied …


Strategies In Developing An Aviation & Aerospace Skill Ecosystem For The State Of Telangana, India – Case Study Of Task -Telangana Academy For Skill And Knowledge, Kim Chua, Sujiv Nair, M.P Ganesh Dr. Jan 2019

Strategies In Developing An Aviation & Aerospace Skill Ecosystem For The State Of Telangana, India – Case Study Of Task -Telangana Academy For Skill And Knowledge, Kim Chua, Sujiv Nair, M.P Ganesh Dr.

International Journal of Aviation, Aeronautics, and Aerospace

The aviation & aerospace sector in India has been expanding and growing through partnerships and new research facilities, thereby encouraging more players to invest and optimize the manufacturing process. Improving green and fuel-efficient technologies have contributed to a steady rise in fuelling the demand for aerospace engineers.

The state of Telangana is fast emerging as a new aviation cluster with some of the country’s best-qualified engineers and technicians. The potential of the aerospace industry is immense as it continuously requires skilled technicians and engineers. Considering the precision of skill required, it is imperative that rigorous training be imparted to all …


Satellite Maintenance: An Opportunity To Minimize The Kessler Effect, Bettina M. Mrusek Dr. Jan 2019

Satellite Maintenance: An Opportunity To Minimize The Kessler Effect, Bettina M. Mrusek Dr.

International Journal of Aviation, Aeronautics, and Aerospace

Recently, there has been an emphasis on the growing problem of orbital debris. While the advantages of placing satellites into space are numerous, advances in satellite technology combined with the growth of the industry have resulted with a significant amount of debris in the orbits surrounding our planet. The harshness of the space environment has also contributed to the debris, as evidenced by the number of objects currently in orbit which are not operational. As the amount of debris grows, so too does the likelihood of collisions, ultimately culminating in the Kessler Effect. However, recent advances in propulsion, advanced navigation, …


Big Five Technologies In Aeronautical Engineering Education: Scoping Review, Ruth Martinez-Lopez Jan 2019

Big Five Technologies In Aeronautical Engineering Education: Scoping Review, Ruth Martinez-Lopez

International Journal of Aviation, Aeronautics, and Aerospace

The constant demands that technology creates in aerospace engineering also influence education. The identification of the technologies with practical application in aerospace engineering is of current interest to decision makers in both universities and industry. A social network approach enhances this scoping review of the research literature to identify the main topics using the Big Five technologies in aerospace engineering education. The conceptual structure of the dataset (n=447) was analyzed from different approaches: at macro-level, a comparative of the digital technology identified by cluster analysis with the number of co-words established in 3 and 8 and, a keyword central structure …


Computational Study Of Flow Interactions Over A Close Coupled Canard-Wing On Fighter, Setyawan Bekti Wibowo, Sutrisno Sutrisno, Tri Agung Rohmat Jan 2019

Computational Study Of Flow Interactions Over A Close Coupled Canard-Wing On Fighter, Setyawan Bekti Wibowo, Sutrisno Sutrisno, Tri Agung Rohmat

International Journal of Aviation, Aeronautics, and Aerospace

There have been many attempts to improve the flying performance of a fighter. By modifying the flow that occurs along the fuselage is expected to improve the performance of the aircraft. One of the indicators of combat aircraft performance is the ability to perform maneuver movement. Adding a canard as forewing on the fighter wing configuration is considered capable of raising the ability in maneuver movement. The use of canard-delta pairs will affect the performance and aerodynamic characteristics of the plane. Wings and canards with delta configuration will make the rolled-up vortex as a lifting force producer on the aircraft. …


Urban Flow And Small Unmanned Aerial System Operations In The Built Environment, Kevin A. Adkins Jan 2019

Urban Flow And Small Unmanned Aerial System Operations In The Built Environment, Kevin A. Adkins

International Journal of Aviation, Aeronautics, and Aerospace

The Federal Aviation Administration (FAA) has put forth a set of regulations (Part 107) that govern small unmanned aerial system (sUAS) operations. These regulations restrict unmanned aircraft (UA) from flying over people and their operation to within visual line of sight (VLOS). However, as new applications for unmanned aerial systems (UAS) are discovered, their capabilities improve, and regulations evolve, there is an increasing desire to undertake urban operations, such as urban air mobility, package delivery, infrastructure inspection, and surveillance. This built environment poses new weather hazards that include enhanced wind shear and turbulence. The smaller physical dimensions, lower mass and …


Aerodynamic Design And Exploration Of A Blended Wing Body Aircraft At Subsonic Speed, Sam Dakka Dr, Oliver Johnson Jan 2019

Aerodynamic Design And Exploration Of A Blended Wing Body Aircraft At Subsonic Speed, Sam Dakka Dr, Oliver Johnson

International Journal of Aviation, Aeronautics, and Aerospace

Blended Wing Body (BWB) is a novel aircraft concept which provides many different aerodynamic benefits over conventional aircrafts design. This research investigated the BWB design, L/D characteristics, surface pressure distribution and span-wise lift distribution of a BWB aircraft at low to medium subsonic speeds. A BWB model was designed, manufactured and tested in a subsonic wind tunnel to validate the CFD simulation. The results gained from the investigation proved that BWB has a L/D improvement of 9.4% than conventional aircrafts and 21% increase at medium subsonic speeds (Mach 0.6) compared to lower subsonic speeds of 25 m/sec. It was found …


A New Method For The Prediction Of The Downwash Angle Gradient, Mondher Yahyaoui Dr. Jan 2019

A New Method For The Prediction Of The Downwash Angle Gradient, Mondher Yahyaoui Dr.

International Journal of Aviation, Aeronautics, and Aerospace

A new method for the prediction of the downwash angle gradient due to aircraft wings across the span of an aft horizontal tail in the incompressible regime is presented. The approach is quite general and accounts for all practical wing geometric parameters except for wing twist where it is shown that this parameter has very little effect on the downwash angle gradient. The method consists of an empirical law which requires the prior knowledge of three constants. These have been computed either based on experimental data when available or using numerical data obtained using the vortex-lattice method. These constants are …


Low Level Turbulence Detection For Airport, Derek Kearney, Anthony O'Connor Jan 2019

Low Level Turbulence Detection For Airport, Derek Kearney, Anthony O'Connor

Articles

Low level wind shear and turbulence present a serious safety risk to aircraft during the approach, landing and take-off phases. Despite many advances in on-board and ground based warning systems. Wind shear remains a formidable force that coupled with a microburst can overpower any aircraft. Aviation reports have concluded that pilots need to have improved information in relation to tailwinds, wind shear and wind variations on approach and during the landing phases. Low level wind shear continues to cause disruption, delays and contribute to aircraft crashes. As recently as 2016, two Boeing aircraft crashed while attempting a Go-around manoeuver after …


Thermodynamic And Transport Properties Of Hydroxylammonium Nitrate-Based Electric Solid Propellant Vapor, Matthew S. Glascock, Patrick D. Drew, Joshua L. Rovey Jan 2019

Thermodynamic And Transport Properties Of Hydroxylammonium Nitrate-Based Electric Solid Propellant Vapor, Matthew S. Glascock, Patrick D. Drew, Joshua L. Rovey

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Electric solid propellants are advanced solid chemical rocket propellants controlled by electric current. Electric solid propellants may also be used in an electric propulsion system, specifically, an ablative pulsed plasma thruster. Previous experiments with the electric solid propellant HIPEP suggest its ablation processes are similar to traditional propellant polytetrafluoroethylene (C2F4). Better understanding of the ablation and resulting propulsion performance of HIPEP requires a model of its vapor composition and transport properties. This paper reports on the development of such a model. The model was validated by comparing results for C2F4 with literature, which showed agreement with multiple models described. Transport …


On Hybrid Temporal Basis Functions For Stable Numerical Solution Of Time Domain Boundary Integral Equations, Fang Q. Hu Jan 2019

On Hybrid Temporal Basis Functions For Stable Numerical Solution Of Time Domain Boundary Integral Equations, Fang Q. Hu

Mathematics & Statistics Faculty Publications

Problems in unsteady aerodynamics and aeroacoustics can sometimes be formulated as integral equations, such as the boundary integral equations. Numerical discretization of integral equations in the time domain often leads to so-called March-On-in-Time (MOT) schemes. In the literature, the temporal basis functions used in MOT schemes have been largely limited to low-order shifted Lagrange basis functions. In order to evaluate the accuracy and effectiveness of the temporal basis functions, a Fourier analysis of the temporal interpolation schemes is carried out. Based on the Fourier analysis, the spectral resolutions of various temporal basis functions are quantified. It is argued that hybrid …


Real-Time Electrical Impedance Monitoring Of Carbon Fiber-Reinforced Polymer Laminates Undergoing Quasi-Static Indentation, Khaled Almuhammadi, Arief Yudhanto, Gilles Lubineau Jan 2019

Real-Time Electrical Impedance Monitoring Of Carbon Fiber-Reinforced Polymer Laminates Undergoing Quasi-Static Indentation, Khaled Almuhammadi, Arief Yudhanto, Gilles Lubineau

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laminated composites are vulnerable to damage from out-of-plane loading, particularly impact loading, and the incurred damage is often only detected by evaluating the post-impact condition of the composites. Real-time monitoring techniques are desirable for early detection of damage. Utilizing changes in the electrical properties of composites to track incurred damage is promising, but the interpretation of such measurements is still challenging. Here, an electro-mechanical system is introduced to understand how well we could detect mechanical degradation in carbon-fiber-reinforced polymer (CFRP) plates undergoing a quasi-static indentation (QSI) test, which is representative of an impact load. The system measures the in situ, …


Impulse Measurements Of Electric Solid Propellant In An Electrothermal Ablation-Fed Pulsed Plasma Thruster, Matthew S. Glascock, Joshua L. Rovey, Kurt A. Polzin Jan 2019

Impulse Measurements Of Electric Solid Propellant In An Electrothermal Ablation-Fed Pulsed Plasma Thruster, Matthew S. Glascock, Joshua L. Rovey, Kurt A. Polzin

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Electric solid propellants are advanced solid chemical rocket propellants that can be controlled (ignited, throttled and extinguished) through the application and removal of an electric current. These propellants are also being considered for use in the ablative pulsed plasma thruster. In this paper, the performance of an electric solid propellant operating in an electrothermal ablation-fed pulsed plasma thruster was investigated using an inverted pendulum micro-Newton thrust stand. The impulse bit and specific impulse of the device using the electric solid propellant were measured for short-duration test runs of 100 pulses and longer-duration runs to end-of-life, at energy levels of 5, …


Electric Solid Propellant Ablation In An Arc Discharge, Matthew S. Glascock, Joshua L. Rovey, Kurt A. Polzin Jan 2019

Electric Solid Propellant Ablation In An Arc Discharge, Matthew S. Glascock, Joshua L. Rovey, Kurt A. Polzin

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Electric solid propellants are advanced solid chemical rocket propellants that can be controlled (ignited, throttled, and extinguished) through the application and removal of an electric current. Electric solid propellants are also being considered for pulsed arc ablation electric thrusters, such as the pulsed plasma thruster. The focus of this work is the electrical and ablation characteristics of electric solid propellant within an arc discharge. Arc discharges of 5–20 J per pulse were created within a cylindrical cavity, and results for the electric solid propellant are compared with polytetrafluoroethylene (PTFE), which is a traditional propellant in ablative pulsed plasma thrusters. The …


Experimental Investigation Of Mixtures Of 1-Ethyl-3-Methylimidazolium Ethyl Sulfate And Ethylammonium Nitrate With Electrospray Propulsion Applications, Mitchell J. Wainwright, Joshua L. Rovey, Shawn W. Miller, Benjamin D. Prince Jan 2019

Experimental Investigation Of Mixtures Of 1-Ethyl-3-Methylimidazolium Ethyl Sulfate And Ethylammonium Nitrate With Electrospray Propulsion Applications, Mitchell J. Wainwright, Joshua L. Rovey, Shawn W. Miller, Benjamin D. Prince

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Physical properties, performance metrics, and mass spectra of mixtures of two ionic liquids (1-ethyl-3-methylimidazolium ethyl-sulfate aka [Emim][EtSO4] and ethyl ammonium nitrate aka EAN) are investigated from the standpoint of electrospray propulsive characteristics. Spectra suggest that as the [Emim][EtSO4] mixture fraction increases, the intensity of [Emim][EtSO4] related species in the plume also increases, while the presence of EAN decreases. Spectra also show presence of both EAN proton transfer species and species related to chemical reaction of [EtSO4] and water. Despite the volatility of EAN, it emits stably into vacuum at low flow rates when mixed with 25% [Emim][EtSO4]. Spectra also show …


Influence Of A Backward-Facing Step On Swept-Wing Boundary-Layer Transition, Jenna L. Eppink, Richard W. Wlezien, Rudolph A. King, Meelan Choudhari Jan 2019

Influence Of A Backward-Facing Step On Swept-Wing Boundary-Layer Transition, Jenna L. Eppink, Richard W. Wlezien, Rudolph A. King, Meelan Choudhari

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Experimental measurements were performed on a swept flat-plate model with an airfoil leading edge and imposed chordwise pressure gradient to determine the effects of a backward-facing step on transition in a low-speed stationary crossflow-dominated boundary layer. Detailed hot-wire measurements were performed for three step heights ranging from 36 to 49% of the boundary-layer thickness at the step and corresponding to subcritical, nearly critical, and critical cases. In general, the step had a small, localized effect on the growth of the stationary crossflow vortex, whereas the unsteady disturbance amplitudes increased with increasing step height. Intermittent spikes in instantaneous velocity began to …


Hydroxylammonium Nitrate Species In A Monopropellant Electrospray Plume, Mitchell J. Wainwright, Joshua L. Rovey, Shawn W. Miller, Benjamin D. Prince, Steven P. Berg Jan 2019

Hydroxylammonium Nitrate Species In A Monopropellant Electrospray Plume, Mitchell J. Wainwright, Joshua L. Rovey, Shawn W. Miller, Benjamin D. Prince, Steven P. Berg

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A mixture of 1-ethyl-3-methylimidazolium ethyl sulfate ([Emim][EtSO4]) and hydroxylammonium nitrate (HAN) is an energetic monopropellant potentially suitable in a multi-mode chemical-electric microtube-electrospray micro propulsion system. In this work, electrospray plume mass spectra are compared between the monopropellant mixture and neat [Emim][EtSO4]. This comparison clearly indicates new and additional species present in the plume due to the addition of HAN. Mass spectra from 20-600 amu/q were obtained over a variety of angles and flow rates from 2 pL/sec to 3 nL/sec in both cation and anion extraction modes. Mass spectrum dependence on flow rate and angular orientation agree qualitatively well with …


An Experimental Approach That Assesses In-Situ Micro-Scale Damage Mechanisms And Fracture Toughness In Thermoplastic Laminates Under Out-Of-Plane Loading, H. Wafai, A. Yudhanto, G. Lubineau, R. Yaldiz, N. Verghese Jan 2019

An Experimental Approach That Assesses In-Situ Micro-Scale Damage Mechanisms And Fracture Toughness In Thermoplastic Laminates Under Out-Of-Plane Loading, H. Wafai, A. Yudhanto, G. Lubineau, R. Yaldiz, N. Verghese

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Studying the response of laminated composites under out-of-plane loading routinely involves mechanical tests, such as quasi-static indentation or impact. The phenomenology during these tests is so complex that it is difficult to identify different material properties related to each failure mechanism (damage mode). We aim at providing an experimental approach, which is practical and fast, for assessing the in-situ micro-scale damage mechanism and extracting the fracture toughness in thermoplastic laminates under out-of-plane loading. To this end, we developed a dedicated, micro-scale, three-point bending (micro-3PB) test fitted inside a scanning electron microscope (SEM). In a single experiment, we were able: (i) …


Determine Airborne Release Fractions (Arf) / Respirable Fractions (Rf) For Use In Safety Based Documents, Michael Quinn, Jacob Miller Jan 2019

Determine Airborne Release Fractions (Arf) / Respirable Fractions (Rf) For Use In Safety Based Documents, Michael Quinn, Jacob Miller

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.


Propagation Of Uncertainty Through Coning, Sculling, And Scrolling Corrections For Inertial Navigation, James Daniel Alan Brouk Jan 2019

Propagation Of Uncertainty Through Coning, Sculling, And Scrolling Corrections For Inertial Navigation, James Daniel Alan Brouk

Masters Theses

"This thesis investigates the propagation of estimation errors through generalized coning, sculling, and scrolling algorithms used in modern day inertial navigation systems, in order to accurately quantify the uncertainty in the estimation of position, velocity, and attitude. The corrections for coning, sculling, and scrolling algorithms have an often unaccounted for effect on documented and empirically derived error statistics for measurements used to predict the uncertainty in a vehicle's position, velocity, and attitude estimates. Through the development of an error analysis for these generalized algorithms, mappings of the measurement and estimation errors through the correction termare generated. Using the developed mappings, …


Small Satellite Earth-To-Moon Direct Transfer Trajectories Using The Cr3bp, Garrett Levi Mcmillan Jan 2019

Small Satellite Earth-To-Moon Direct Transfer Trajectories Using The Cr3bp, Garrett Levi Mcmillan

Masters Theses

"The CubeSat/small satellite field is one of the fastest growing means of space exploration, with applications continuing to expand for component development, communication, and scientific research. This thesis study focuses on establishing suitable small satellite Earth-to-Moon direct-transfer trajectories, providing a baseline understanding of their propulsive demands, determining currently available off-the-shelf propulsive technology capable of meeting these demands, as well as demonstrating the effectiveness of the Circular Restricted Three Body Problem (CR3BP) for preliminary mission design. Using the CR3BP and derived requirements from NASA's Cube Quest Challenge, five different trajectory scenarios were analyzed for their propulsive requirements. Results indicate that the …


A Systems And Cost Analysis Of Human Rated Mars Entry, Descent, And Landing Vehicles, Paul Daniel Friz Jan 2019

A Systems And Cost Analysis Of Human Rated Mars Entry, Descent, And Landing Vehicles, Paul Daniel Friz

Doctoral Dissertations

"Cost is one of the biggest obstacles to sending humans to Mars. However, spacecraft costs are typically not taken into consideration until after the preliminary vehicle and mission concepts have been designed. Once costs have been estimated, managers and project teams often lack confidence that the final cost of the mission will match the preliminary estimates. The present work provides a robust methodology for using cost as a valid metric early in the design phase of future human Mars Entry, Descent, and Landing (EDL) vehicles. This is done in three parts. First, state of the art parametric costing methods are …


Study Of Optical Propulsion Concepts And Techniques For Small-Satellites, Jaykob Neil Maser Jan 2019

Study Of Optical Propulsion Concepts And Techniques For Small-Satellites, Jaykob Neil Maser

Doctoral Dissertations

"The first objective of this research is to manufacture and investigate the characteristics and use of asymmetric, metallic, nanostructures for plasmonic force propulsion, a developing method of nano-/picosatellite thrust generation. This project developed a higher-fidelity model of a recently envisioned small spacecraft propulsion system for precision pointing and proximity control. Plasmonic force propulsion harnesses solar light focused onto plasmon reactive sub-wavelength nanostructures to generate polarized oscillations of electrons on the surface of metallic nanostructures which accelerate and expel nanoparticle propellant via strong optical forces. This research also explores how material selection affects the electromagnetic response of the closely positioned asymmetric …


Atomistic Simulations Of Nanoindentation Response Of Irradiation Defects In Iron, M. Mustafa Azeem, Qingyu Wang, Muhammad Zubair Jan 2019

Atomistic Simulations Of Nanoindentation Response Of Irradiation Defects In Iron, M. Mustafa Azeem, Qingyu Wang, Muhammad Zubair

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Radiation response of a material is a consequence of defects' evolution in any radiation damage event. The radiation-induced defects can significantly alter the mechanical properties of a material. Radiation damage initiates from incident neutron by bombardment on solid material causing production and evolution of Frenkel defects. Since voids are formed due to aggregation of a large number of vacancies that cause dimensional changes and hence irradiation-induced swelling. In order to characterize the effect of irradiation defects, we have performed molecular dynamics (MD) simulations to investigate nanoindentation response of point defects and voids in Fe and their effects on mechanical parameters. …