Comparison Of Radiation Dosage For Human Piloted Mars Missions Using Chemical, Nuclear Thermal, And Fusion Propulsion Systems,
2015
University of Alabama in Huntsville
Comparison Of Radiation Dosage For Human Piloted Mars Missions Using Chemical, Nuclear Thermal, And Fusion Propulsion Systems, Steven Doyle
Research Horizons Day Posters
No abstract provided.
Slip Length Crossover On A Graphene Surface,
2015
Missouri University of Science and Technology
Slip Length Crossover On A Graphene Surface, Zhi Liang, Pawel Keblinski
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Using Equilibrium and Non-Equilibrium Molecular Dynamics Simulations, We Study the Flow of Argon Fluid above the Critical Temperature in a Planar Nanochannel Delimited by Graphene Walls. We Observe that, as a Function of Pressure, the Slip Length First Decreases Due to the Decreasing Mean Free Path of Gas Molecules, Reaches the Minimum Value When the Pressure is Close to the Critical Pressure, and Then Increases with Further Increase in Pressure. We Demonstrate that the Slip Length Increase at High Pressures is Due to the Fact that the Viscosity of Fluid Increases Much Faster with Pressure Than the Friction Coefficient between …
Lift Generating Device,
2015
Embry-Riddle Aeronautical University
Lift Generating Device, Juan A. Alvarado
Publications
A lift generating device is provided enabling vertical flight. The lift generating device includes a first revolution structure having a funnel shape and a second revolution structure having a funnel shape. Each revolution structure includes a circular open surface and an open stem. The second revolution structure is attached to the first revolution structure by a plurality of connectors so as to form a gap between the first revolution structure and the second revolution structure. A propeller is coupled to an open stem at a bottom end of the first revolution structure and a motor is operatively connected to the …
Grid And Solution Adaptation Via Direct Optimization Methods,
2015
University of Akron, main campus
Grid And Solution Adaptation Via Direct Optimization Methods, Ajay Mahajan
Dr. Ajay Mahajan
At present all numerical schemes based on some form of differencing approach are plagued by some lack of accuracy when compared to the exact solution. This lack of accuracy can be attributed to the presence of truncation error in the numerical method. Traditionally the error can be reduced by increasing the number of mesh points in the discrete domain or by implementing a higher order numerical scheme. In recent times the approach has taken a more intelligent direction where adaptation or distribution of the mesh points is affected in such a way to reduce the error. However, grid adaptation with …
Review Of Seal Designs On The Apollo Spacecraft,
2015
The Unversity of Akron, Main Campus
Review Of Seal Designs On The Apollo Spacecraft, Joshua Finkbeiner, Patrick Dunlap, Bruce Steinetz, Christopher Daniels
Dr. Christopher C Daniels
The Apollo spacecraft required a variety of seal designs to support human spaceflight to the moon and to return the crew safely to Earth. High-temperature seals were required for gaps in the thermal protection system to protect the underlying structures from the high heating environment of super orbital reentry. Reliable pressure seals were also required to prevent the loss of habitable atmosphere during missions to the moon...
Unmanned Aerial Vehicle (Uav) Propulsion Research: Conceptual Studies Of “Ultra-Compact Shaft-Less Jet Engines” For Next Generation Uavs,
2015
Embry-Riddle Aeronautical University
Unmanned Aerial Vehicle (Uav) Propulsion Research: Conceptual Studies Of “Ultra-Compact Shaft-Less Jet Engines” For Next Generation Uavs, Tyler Eiguren, Trevor Douglas, Tre Buchanan
Publications
Unmanned Aerial Vehicles are becoming more commonly used in today’s society, ranging anywhere from military applications to entertainment for enthusiasts and hobbyists. The complexity of current generation UAV’s propulsive devices, based upon a scaled turbine engine and separate gas & electrically powered rotating fan blades, require regular maintenance for every 24 hours of flight. This added cost coupled with necessary intricate machinery deters UAV designers from such engines, leaving a void in current production. Our research team believes that by combining a simplified alternative compression & combustion process with an electrically driven fan, we can develop an energy efficient, reliable, …
The Panther: 2015 Aiaa Design Build Fly,
2015
Embry-Riddle Aeronautical University
The Panther: 2015 Aiaa Design Build Fly, Bryce Milnes, Chris Crawford
Publications
The ERAU Prescott chapter of AIAA participated in the 2015 AIAA Design Build Fly competition at Raytheon Missile Systems in Tucson from April 10-12. A remote controlled aircraft meeting and exceeding all competition performance requirements was designed and fabricated by the 30+ students of the team. Additionally, a 60 page report was submitted detailing the project starting from initial considerations and advancing through flight test verification of aircraft capabilities. The success of this project was enabled by the E-Prize and SGA funding received to support our efforts throughout the year. The lessons learned regarding management and planning, engineering design approaches, …
Morris Leroy Spearman,
2015
Old Dominion University
Scalloped Leading Edge Vaned Diffuser Analysis For A Compact High Pressure Ratio Centrifugal Compressor,
2015
Embry-Riddle Aeronautical University
Scalloped Leading Edge Vaned Diffuser Analysis For A Compact High Pressure Ratio Centrifugal Compressor, Vinod Poonamchand Gehlot
Doctoral Dissertations and Master's Theses
Microturbines and small gas turbines are often an attractive option for turbo-hybryd application research in aviation due to their simple design and high power to weight ratio. However, the low operating pressure ratios of microturbines leads to low thermal efficiency, which results in very high fuel consumption. Higher operating pressure ratios in microturbines could vastly improve their current fuel efficiency. This thesis focuses on developing a compact, single stage 8:1 pressure ratio centrifugal compressor stage designed to meet the high-pressure ratio requirements of microturbines and small gas turbine engines in turbo hybrid-electric propulsion applications. The first stage vaned diffuser was …
System Importance Measures: A New Approach To Resilient Systems-Of-Systems,
2015
Purdue University
System Importance Measures: A New Approach To Resilient Systems-Of-Systems, Payuna Uday
Open Access Dissertations
Resilience is the ability to withstand and recover rapidly from disruptions. While this attribute has been the focus of research in several fields, in the case of system-of-systems (SoSs), addressing resilience is particularly interesting and challenging. As infrastructure SoSs, such as power, transportation, and communication networks, grow in complexity and interconnectivity, measuring and improving the resilience of these SoSs is vital in terms of safety and providing uninterrupted services. ^ The characteristics of systems-of-systems make analysis and design of resilience challenging. However, these features also offer opportunities to make SoSs resilient using unconventional methods. In this research, we present a …
Design Of Low-Thrust Missions To Asteroids With Analysis Of The Missed-Thrust Problem,
2015
Purdue University
Design Of Low-Thrust Missions To Asteroids With Analysis Of The Missed-Thrust Problem, Frank E. Laipert
Open Access Dissertations
Small bodies in the Solar System, such as asteroids and dwarf planets, are ideal targets for electric propulsion missions because of the high delta-V required to rendezvous with these targets. We study trajectories to the asteroid belt, including a human mission to Ceres and a sample return mission to (216) Kleopatra, along with trajectories to the Jupiter Trojan asteroids. For the human mission to Ceres, payload masses of 75 Mg are achievable with a 11.7 MW nuclear electric propulsion system and an initial mass in LEO of 289 Mg. For low-thrust sample return missions to the main belt asteroid Kleopatra, …
Loss Of Accuracy Using Smeared Properties In Composite Beam Modeling,
2015
Purdue University
Loss Of Accuracy Using Smeared Properties In Composite Beam Modeling, Ning Liu
Open Access Theses
Advanced composite materials have broad, proven applications in many engineering systems ranging from sports equipment sectors to components on the space shuttle because of their lightweight characteristics and significantly high stiffness. Together with this merit of composite materials is the challenge of improving computational simulation process for composites analysis. Composite structures, particularly composite laminates, usually consist of many layers with different lay-up angles. The anisotropic and heterogeneous features render 3D finite element analysis (FEA) computationally expensive in terms of the computational time and the computing power. ^ At the constituent level, composite materials are heterogeneous. But quite often one homogenizes …
Comprehensively Simulating The Mixed-Mode Progressive Delamination In Composite Laminates,
2015
Purdue University
Comprehensively Simulating The Mixed-Mode Progressive Delamination In Composite Laminates, Zhenyuan Gao
Open Access Theses
Delamination, or interlaminar debonding, is a commonly observed failure mechanism in composite laminates. It is of great significance to comprehensively simulate the mixed-mode progressive delamination in composite structures because by doing this, people can save a lot of effort in evaluating the safe load which a composite structure can endure.^ The objective of this thesis is to develop a numerical approach to simulating double-cantilever beam (DCB) and mixed-mode bending (MMB) tests and also of specifying/validating various cohesive models. A finite element framework, which consists of properly selecting time integration scheme (explicit dynamic), viscosity, load rate and mass scaling, is developed …
Performance Analysis Of Vortex Based Mixers For Confined Flows,
2015
Purdue University
Performance Analysis Of Vortex Based Mixers For Confined Flows, Timo Buschhagen
Open Access Theses
The hybrid rocket is still sparsely employed within major space or defense projects due to their relatively poor combustion efficiency and low fuel grain regression rate. Although hybrid rockets can claim advantages in safety, environmental and performance aspects against established solid and liquid propellant systems, the boundary layer combustion process and the diffusion based mixing within a hybrid rocket grain port leaves the core flow unmixed and limits the system performance. One principle used to enhance the mixing of gaseous flows is to induce streamwise vorticity. The counter-rotating vortex pair (CVP) mixer utilizes this principle and introduces two vortices into …
Flexible Weapons Architecture Design,
2015
Purdue University
Flexible Weapons Architecture Design, William C. Pyant
Open Access Theses
Present day air-delivered weapons are of a closed architecture, with little to no ability to tailor the weapon for the individual engagement. The closed architectures require weaponeers to make the target fit the weapon instead of fitting the individual weapons to a target. The concept of a flexible weapons aims to modularize weapons design using an open architecture shell into which different modules are inserted to achieve the desired target fractional damage while reducing cost and civilian casualties. This thesis shows that the architecture design factors of damage mechanism, fusing, weapons weight, guidance, and propulsion are significant in enhancing weapon …
Ads-B Used In Improvement Of Air Traffic Control,
2015
Purdue University
Ads-B Used In Improvement Of Air Traffic Control, Hao Wang
Open Access Theses
Automatic dependent surveillance – broadcast (ADS-B) is a central component of the NextGen air traffic control program. This surveillance technology can replace current secondary surveillance radars (SSR) and improve cockpit situational awareness. The service can improve traffic surveillance capabilities by sharing accurate aircraft position information between pilots and air traffic controllers. In addition, ADS-B provides pilots with weather as well as air traffic information for nearby area. In order to receive these traffic and weather services, a pilot must have appropriate onboard equipment including GPS receiver, Universal Access Transceiver, antenna and multi-function cockpit display which is capable of receiving and …
Is Aerospace Important To The United States?,
2015
Omaha North High Magnet School
Is Aerospace Important To The United States?, Joshua Romer
Nebraska College Preparatory Academy: Senior Capstone Projects
Aerospace is technology and industry in space flight and avia:on. It provides safe and faster means of transporta:on, explora:on, and electronics. Aerospace is responsible for many US exports and improvements. Aerospace is important to research because of its lack of publicity.
Design Of Transfers From Earth-Moon L 1/L2 Libration Point Orbits To A Destination Object,
2015
Purdue University
Design Of Transfers From Earth-Moon L 1/L2 Libration Point Orbits To A Destination Object, Masaki Kakoi
Open Access Dissertations
Within the context of both manned and robotic spaceflight activities, orbits near the Earth-Moon L1 and L2 libration points could support lunar surface operations and serve as staging areas for future missions to near-Earth asteroids as well as Mars. In fact, an Earth-Moon L2 libration point orbit has been proposed as a potential hub for excursions to Mars as well as activities in support of planetary exploration. Yet, the dynamical environment within the Earth-Moon system is complex and, consequently, trajectory design in the vicinity of Earth-Moon L1 and L2 is nontrivial. Routine transfers between an Earth-Moon L1/L2 facility and Mars …
Maneuver Analysis For Spinning Thrusting Spacecraft And Spinning Tethered Spacecraft,
2015
Purdue University
Maneuver Analysis For Spinning Thrusting Spacecraft And Spinning Tethered Spacecraft, Kaela Mae Martin
Open Access Dissertations
During axial thrusting of a spin-stabilized spacecraft undergoing orbital injections or control maneuvers, misalignments and center-of-mass offset create undesired body-fixed torques. The effects of the body-fixed torques, which in turn cause velocity pointing errors, can be reduced by ramping up (and then ramping down) the thruster. The first topic discussed in this thesis derives closed-form solutions for the angular velocity, Euler angles, inertial velocity, and inertial displacement solutions with nonzero initial conditions. Using the closed-form solutions, the effect of variations in the spin-axis moment of inertia and spin-rate on the spacecraft velocity pointing error are shown. The analytical solutions closely …
An Experimental Study On The Effects Of Blade Row Interactions On Aerodynamic Loss Mechanisms In A Multistage Compressor,
2015
Purdue University
An Experimental Study On The Effects Of Blade Row Interactions On Aerodynamic Loss Mechanisms In A Multistage Compressor, Natalie Rochelle Smith
Open Access Dissertations
While the gas turbine engine has existed for nearly 80 years, much of the complex aerodynamics which governs compressor performance is still not well understood. The unsteady flow field consists of periodic blade row interactions from the wakes and potential fields of each blade and vane. Vane clocking is the relative circumferential indexing of adjacent vane rows with the same vane count, and it is one method to change blade row interactions. Though the potential of performance benefits with vane clocking is known, the driving flow physics have yet to be identified. ^ This research examines the effects of blade …
