Aerospace Engineering Commons^™

Proposal To Augment U.S. Army Lsa And Uars, Cameron Beard

Discovery Day - Prescott

The U.S. Army currently has a gap in its aerial reconnaissance capabilities, with the OH-58D Kiowa completing its phase transition to the AH-64E. Since the Army has done away with its rotary-wing scout aircraft, it currently relies on the AH-64E attack helicopter (an aircraft not designed for such a role), in tandem with UAS RQ- 7Bs and MQ-1C Grey Eagle. These aircraft use the MUM-T (Manned-Unmanned Teaming) system, which allows AH-64E pilots to control the camera and weaponry of the drones while both aircraft are in flight. The draw back to this system lies in two categories; 1) the inability …

Tip Driven Rotor System, Kevin Allyas

Discovery Day - Prescott

The Tip-Driven Rotor System (TDRS) Project is a product designed for KRyanCreative, LLC (KRC), as the basis of a Levitated Annular Rotor System (LARS) for commercial and tactical military vertical takeoff and landing (VTOL) vehicles. Conceptually, this design will greatly increase power density and lift capacity over conventional shaft-centric helicopters. The design also enables variable rotational velocity control that can greatly expand the VTOL flight envelope. The LARS innovatively leverages electromagnetism and superconductive levitation in the transfer of energy from vehicle source to aerodynamic lifting surface. The benefits of LARS include: the reduction of wing tip vortices due to a …

Impact Of Ultrathin Coating Layer On Lithium-Ion Intercalation Into Particles For Lithium-Ion Batteries, Yufang He, Hiep Pham, Xinhua Liang, Jonghyun Park

Chemical and Biochemical Engineering Faculty Research & Creative Works

Ultrathin film coatings on battery materials via atomic layer deposition (ALD) have been demonstrated as an efficient technology for battery performance enhancement. However, the fundamental understanding on lithium intercalation into active materials through the interface between the coating and active materials is unclear, which makes it difficult to optimize ALD coating strategies. Further, like most active materials, a coating layer can undergo volume change during the intercalation process, which can produce detrimental structural changes and mechanical failure of the layer. In this work, first-principles calculations are conducted to reveal the behavior of a coating layer on an active material particle …

The Business Of Moving A Library, Gabriele Hysong

Midwest Business Librarian Summit (MBLS)

No abstract provided.

Proper Orthogonal Decomposition Of Reynolds And Dispersive Stresses In Turbulent Boundary Layers Over Multi-Scale Rough Patches, Catherine Virginia Spivey

Dissertations and Theses

Multi-scale rough patches are present in topologies such as urban canopies (cities) and natural landscapes (forests, ocean floors). The flow over such canopies is three-dimensional, with turbulent structures known as secondary flows present in the boundary layer due to the difference in rough surface heterogeneities. Three dimensional instantaneous velocities are analyzed within the roughness sublayer over three generations of multi-scale rough patches at nine vertical planes using particle image velocimetry obtained experimentally. The secondary structures present in the flow are identified in the form of Reynolds and dispersive fluctuations. Proper orthogonal decomposition is employed to characterize the imprint of the …

Incorporation Of Trajectory Behaviors In The Vicinities Of Different Planetary Moons Using Finite-Time Lyapunov Exponent Maps, David Canales Garcia, Kathleen C. Howell, Elena Fantino

PanaSoMM

There is an increasing interest in future space missions devoted to the exploration of key moons in the Solar system. These many different missions may involve libration point orbits as well as trajectories that satisfy different endgames in the vicinities of the moons. To this end, an efficient design strategy to produce low-energy transfers between the vicinities of adjacent moons of a planetary system is introduced that leverages the dynamics in these multi-body systems. Such a design strategy is denoted as the moon-to-moon analytical transfer (MMAT) method. It consists of a general methodology for transfer design between the vicinities of …

Ci Asteroid Regolith As An In Situ Plant Growth Medium For Space Crop Production, Steven J. Russell, Sherry Fieber-Beyer, Kathryn A. Yurkonis

Biology Faculty Publications

Human expansion into the solar system is currently at the forefront of space research. For our astronauts to survive, they will need to be fed a healthy and nutritious diet on a consistent basis. Right now, our current method of feeding astronauts consists of resupplied prepackaged food from Earth, which is unsustainable for long-term missions. Using planetary resources via in situ resource utilization to grow crops is the next step toward sustainability in space. Asteroids are an abundant space resource and should not be overlooked when considering crewed missions. In particular, the primordial CI carbonaceous asteroids are of interest because …

A Comparative Study On Representativeness And Stochastic Efficacy Of Miniature Tensile Specimen Testing, Sreekar Karnati, Sriram Praneeth Isanaka, Yunlu Zhang, Frank W. Liou, Jason L. Schulthess

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this article, a miniature dog bone tensile coupon design was tested against the existing ASTM standard specimen design. Specimens were prepared from commercially sourced austenitic stainless steel 304 alloy, and a defect-ridden additively manufactured 304L alloy was studied. By utilizing a tensile specimen design that is 1/230th volume of the smallest ASTM E8-04 (2016), Standard Test Methods for Tension Testing of Metallic Materials, dog bone specimen, coupled to a digital image correlation (DIC) setup, case studies were performed to compare tensile property measurements and strain field evolution. Whereas yield strength measurements were observed to be similar, post-yield, the ultimate …

Structural Health Monitoring Of Fatigue Cracks For Steel Bridges With Wireless Large-Area Strain Sensors, Sdiq Anwar Taher, Jian Li, Jong-Hyun Jeong, Simon Laflamme, Hongki Jo, Caroline Bennett, William N. Collins, Austin Downey

Faculty Publications

This paper presents a field implementation of the structural health monitoring (SHM) of fatigue cracks for steel bridge structures. Steel bridges experience fatigue cracks under repetitive traffic loading, which pose great threats to their structural integrity and can lead to catastrophic failures. Currently, accurate and reliable fatigue crack monitoring for the safety assessment of bridges is still a difficult task. On the other hand, wireless smart sensors have achieved great success in global SHM by enabling long-term modal identifications of civil structures. However, long-term field monitoring of localized damage such as fatigue cracks has been limited due to the lack …

Effects Of Pulsatile Flow Rate And Shunt Ratio In Bifurcated Distal Arteries On Hemodynamic Characteristics Involved In Two Patient-Specific Internal Carotid Artery Sidewall Aneurysms: A Numerical Study, Hang Yi, Mark Johnson, Luke C. Bramlage, Bryan Ludwig, Zifeng Yang

Mechanical and Materials Engineering Faculty Publications

The pulsatile flow rate (PFR) in the cerebral artery system and shunt ratios in bifurcated arteries are two patient-specific parameters that may affect the hemodynamic characteristics in the pathobiology of cerebral aneurysms, which needs to be identified comprehensively. Accordingly, a systematic study was employed to study the effects of pulsatile flow rate (i.e., PFR−I, PFR−II, and PFR−III) and shunt ratio (i.e., 75:25 and 64:36) in bifurcated distal arteries, and transient cardiac pulsatile waveform on hemodynamic patterns in two internal carotid artery sidewall aneurysm models using computational fluid dynamics (CFD) modeling. Numerical results indicate that larger PFRs can cause higher wall …

Behavioral Intention Factors For Prescription Deliveries By Small Unmanned Aircraft In Rural Communities, Sarah M. Talley

Doctoral Dissertations and Master's Theses

Nearly half of the U.S. population regularly use and depend on prescription medications; however, pharmacy availability and access to pharmacy services are often lacking, particularly in rural communities. In an effort to meet local healthcare needs, delivery by sUAS is proposed to ensure the nearly 60 million rural residents have access to their prescription medications.

As an emerging technology with little research into home delivery applications, the successful implementation of sUAS for prescription medication delivery requires public acceptance and positive behavioral intention toward its use. At the time of the current research, no prior studies have specifically focused on the …

Experimental Characterization Of Additively Manufactured Multi-Feather Wingtip Devices, Patricio Garzon

Doctoral Dissertations and Master's Theses

Soaring birds have evolved to fly for long periods of time without flapping their wings. Inspired by the flight of these birds, the proposed thesis presents an experimental investigation focused on wingtip devices designed based on biomimicry. The overarching engineering objective was to reduce the induced drag as a means to improve the fuel efficiency via these experimental wingtips. An associated secondary objective was to establish a method for manufacturing complex structures suitable for wing tunnel testing. A manufacturing technique that involved using composite weaves to reinforce additively manufactured structures was developed. This technique has the potential to reduce manufacturing …

Effect Of Spray Rails On Takeoff Performance Of Amphibian Aircraft, Soham Bahulekar

Doctoral Dissertations and Master's Theses

Amphibian aircraft have seen a rise in popularity in the recreational and utility sectors due to their ability to take off and land on both land and water, thus serving a myriad of purposes such as aerobatics, surveillance, and firefighting. The design of such seaplanes requires to be both aerodynamically and hydrodynamically efficient, especially during the takeoff phase. In the past, naval architects have implemented ways to make boats, yachts, and large ships more efficient; one of them being the addition of chine strips and spray rails on the hull. This thesis study explores the possibility of implementing spray rails …

Synthetic Gecko Inspired Dry Adhesive Through Two-Photon Polymerization For Space Applications, Zefu Ren

Doctoral Dissertations and Master's Theses

This work aims to develop an advanced and cost-effective fabrication process to produce a simplified gecko-inspired microstructure with two-photon polymerization and polymer molding, aimed to improve the adhesive properties of microstructures. Such adhesive microstructures can be implemented for multi-purpose adhesive grasping devices, which have recently gained significant interest in the space exploration sector. Previous gecko-inspired microstructures were reviewed, and the new gecko-inspired microstructures have been developed with the adaptation of additive manufacturing methods for facile fabrication. The examined microstructures in this thesis were the tilted mushroom-shaped and wedge-shaped designs, which could both maximize adhesion by shearing the micropillars toward the …

Optimization Of Rover Wheel Geometries For Planetary Missions, Nikita Amberkar

Doctoral Dissertations and Master's Theses

Rovers have been launched into space for exploration of the Moon and Mars to collect samples of rock and soil. To continue the explorations, the rovers need to have reliable wheels to drive around. However, due to the soil being soft, the wheels on the rover start to lose traction and the wheels sink while driving to various locations. Previous work in this field has been done experimentally or with the use of simulations. Only a few references report the effect of uncertainties in grouser simulation on the traction efficiency. The objective of this work was to (a) Understand the …

Numerical Study Of The Effects Of Injector Geometry On The Performance Of Rotating Detonation Engines, Xavier Roy

Theses and Dissertations

A study of the impact of injector geometry on the performance of rotating detonation engines is performed. A numerical scheme is developed to represent the rotating detonation engine physics. In order to simulate the interaction between the chamber and the injectors, a multizone capability is implemented inside the numerical tool. The model is calibrated to represent a hydrogen-air detonation. The rotating detonation engine annular chamber is unwrapped and studied as a two-dimensional planar domain with a periodic boundary condition. Several numerical experiments are conducted. In particular, injection parameters are examined, such as the injector inflow to channel area ratio, injection …

Exploring Passive Flow Control Techniques Applied To A Supersonic Multistream Rectangular Nozzle, Emma Dawn Gist

Dissertations - ALL

Passive control techniques are applied experimentally to examine different aspects of a supersonic multistream rectangular nozzle representing a modern airframe-integrated variable cycle engine. The flow is comprised of a core stream (M = 1.6) and bypass (M = 1.0) that merge behind a splitter plate and exit through a Single Expansion Ramp Nozzle (SERN) onto an aft-deck. Previous efforts for the nominal nozzle configuration have shown that an instability initiated at the splitter plate trailing edge (SPTE) influences the effectiveness of the third stream as a barrier for the aft-deck and persists through the entire do- main due to its …

In-Situ Infrared Thermographic Inspection For Local Powder Layer Thickness Measurement In Laser Powder Bed Fusion, Tao Liu, Cody S. Lough, Hossein Sehhat, Yi Ming Ren, Panagiotis D. Christofides, Edward C. Kinzel, Ming-Chuan Leu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The laser powder bed fusion (LPBF) process is strongly influenced by the characteristics of the powder layer, including its thickness and thermal transport properties. This paper investigates in-situ characterization of the powder layer using thermographic inspection. A thermal camera monitors the temperature history of the powder surface immediately after a layer of new powder is deposited by the recoating system. During this process, thermal energy diffuses from the underlying solid part, eventually raising the temperature of the above powder layer. Guided by 1D modeling of this heat-up process, experiments show how the parameterized thermal history can be correlated with powder …

Electromagnetic Interference Shielding Effectiveness Of A Layered System Consisting Of A Carbon Nano-Reinforced Polymer Composite Coated With Metal Oxide And Graphite, Veronica Montserrat Serrato

Theses and Dissertations

In this study, the electromagnetic interference (EMI) shielding effectiveness (SE) of vapor grown carbon nanofiber (VGCNF) reinforced polyvinylidene difluoride (PVDF) composite and PVDF/VGCNF thermally sprayed with magnetite (Fe3O4) and graphite has been investigated. EMI SE evaluations were performed in the frequency range of 30 kHz-1.5 GHz. The developed nanocomposite (NC) system was fabricated by high shear mixing using a Banbury type mixer. The material was then subjected to compression molding. Subsequently, the films were thermally sprayed using Fe3O4/graphite powder. The NC and coated NC films had average thicknesses of 0.82 mm and 0.93 mm, respectively. The NC films were subjected …

Internal Energy Balance And Aerodynamic Heating Predictions For Hypersonic Turbulent Boundary Layers, Matthew Barone, Gary L. Nicholson, Lian Duan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The elemental equation governing heat transfer in aerodynamic flows is the internal energy equation. For a boundary layer flow, a double integration of the Reynolds-averaged form of this equation provides an expression of the wall heat flux in terms of the integrated effects, over the boundary layer, of various physical processes: turbulent dissipation, mean dissipation, turbulent heat flux, etc. Recently available direct numerical simulation data for a Mach 11 cold-wall turbulent boundary layer allows a comparison of the exact contributions of these terms in the energy equation to the wall heat flux with their counterparts modeled in the Reynolds-averaged Navier-Stokes …