Engineering Commons^™

Wireless Antenna Sensors For Boiler Condition Monitoring, Franck Tchafa

Mechanical and Aerospace Engineering Dissertations - Archive

Structural Health Monitoring (SHM) is a vital technology that implements real-time condition monitoring or damage detection mechanisms for the safety assurance of structural systems such as power stations, aircrafts, bridges, dams, buildings, large machinery, and more. Without proper and timely maintenance, mechanical systems are prone to failures since they experience detrimental factors such as harsh environments, excessive loads, and vibrations. Several sensing technologies exist for SHM applications. Patch antennas are among the list of these technologies, and they are an attractive choice due to their compact size, light weight, ease of manufacturing, and low fabrication cost. Patch antennas have been …

Fast Prediction Of Thermal Distortion In Metal Powder Bed Fusion Additive Manufacturing: Part 1, A Thermal Circuit Network Model, Hao Peng, Morteza Ghasri-Khouzani, Shan Gong, Ross Attardo, Pierre Ostiguy, Bernice Aboud Gatrell, Joseph Budzinski, Charles Tomonto, Joel Neidig, M. Ravi Shankar, Richard Billo, David B. Go, David Hoelzle

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The additive manufacturing (AM) process metal powder bed fusion (PBF) can quickly produce complex parts with mechanical properties comparable to wrought materials. However, thermal stress accumulated during PBF induces part distortion, potentially yielding parts out of specification and frequently process failure. This manuscript is the first of two companion manuscripts that introduce a computationally efficient distortion and stress prediction algorithm that is designed to drastically reduce compute time when integrated in to a process design optimization routine. In this first manuscript, we introduce a thermal circuit network (TCN) model to estimate the part temperature history during PBF, a major computational …

Command Governor-Based Adaptive Control For Dynamical Systems With Matched And Unmatched Uncertainties, Metehan Yayla, Ehsan Arabi, Ali Turker Kutay, Tansel Yucelen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this paper, we propose a command governor-based adaptive control architecture for stabilizing uncertain dynamical systems with not only matched but also unmatched uncertainties and achieving the desired command following performance of a user-defined subset of the accessible states. In our proposed solution, online least-squares solutions for the matched and unmatched parameters are obtained through integration method and they are employed in the adaptive control framework. Specifically, the matched uncertainty is identified and its effect upon the system behavior is entirely attenuated. Moreover, using the unmatched uncertainty approximation obtained through radial basis function neural networks, the command governor signal is …

Fast Prediction Of Thermal Distortion In Metal Powder Bed Fusion Additive Manufacturing: Part 2, A Quasi-Static Thermo-Mechanical Model, Hao Peng, Morteza Ghasri-Khouzani, Shan Gong, Ross Attardo, Pierre Ostiguy, Ronald B. Rogge, Bernice Aboud Gatrell, Joseph Budzinski, Charles Tomonto, Joel Neidig, M. Ravi Shankar, Richard Billo, David B. Go, David Hoelzle

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The additive manufacturing (AM) process metal powder bed fusion (PBF) can quickly produce complex parts with mechanical properties comparable to that of wrought materials. However, thermal stress accumulated during Metal PBF may induce part distortion and even cause failure of the entire process. This manuscript is the second part of two companion manuscripts that collectively present a part-scale simulation method for fast prediction of thermal distortion in Metal PBF. The first part provides a fast prediction of the temperature history in the part via a thermal circuit network (TCN) model. This second part uses the temperature history from the TCN …

High Dynamic Range Optical Devices And Applications., Elijah Robert Jensen

Electronic Theses and Dissertations

Much of what we know about fundamental physical law and the universe derives from observations and measurements using optical methods. The passive use of the electromagnetic spectrum can be the best way of studying physical phenomenon in general with minimal disturbance of the system in the process. While for many applications ambient visible light is sufficient, light outside of the visible range may convey more information. The signals of interest are also often a small fraction of the background, and their changes occur on time scales so quickly that they are visually imperceptible. This thesis reports techniques and technologies developed …

Shape Optimization Of A Fan Duncte For A Vertical Takeoff And Landing, Jie Hua

Mechanical and Aerospace Engineering Theses - Archive

The popularity of ride sharing services and recent improvements in electric car performance and automation have sparked interest in E-VTOL (Electric Vertical Takeoff and Landing) aircraft for personal transportation. Companies such as Uber, Airbus and EHANG are currently researching such aircraft for transportation over short distances in crowded urban environments. A personal E-VTOL design based on a ducted fan concept is proposed and the vertical lift capability is optimized. A numerical optimization algorithm is coupled with a computational fluid dynamics (CFD) analysis code to perform shape optimization. The objective is to determine the internal and external duct shape that maximizes …

A Study Of Effect Of Bond Length On Bond Strength Using Transient Heat Transfer Analysis, Junaid Mohamed Baig

Mechanical and Aerospace Engineering Theses - Archive

It is important to understand the mechanical properties of the bonding between the adjacent layers of 3D printed parts build by fused deposition modeling. The bonding process is highly nonlinear and depends on various geometrical and thermal process parameters. This work aims to quantify the degree of bonding by calculating bond potential between the extruded layers using finite element heat transfer analysis. Successive transient analysis were carried out using this model by constantly updating the boundary conditions and geometric model during the deposition of the extruded bead. Temperatures at critical points were calculated over a period to calculate the bond …

Inverse Analysis Of Heat Generating Body For Safety Applications, Sandeep Patil

Mechanical and Aerospace Engineering Dissertations - Archive

Inverse thermal analysis and its applications have been applied to numerous fields of science and engineering. Historically during the 1950's and early 1960's, space programs played a significant role in the advancement of solution techniques for Inverse Heat transfer Problems(IHTP). It was applied to measure the surface temperature of thermal shield of a space vehicle during its re-entry into atmosphere. Inverse analysis was also used in the estimation of thermo-physical properties of the shield at high operating temperatures. Besides thermal application, inverse technique was also used in other engineering applications such as estimation of alloy specification, design of a shape …

Optimization Of Board Level Reliability Of Microelectronic Packages And Modules, Alok Kumar Lohia

Mechanical and Aerospace Engineering Dissertations - Archive

Thermo-mechanical reliability estimation of electronic packages and modules provides an opportunity to predict the function life of semiconductor devices. The problem complexity lies in the fact that there are variety of electronic packages with different form factors, materials and manufacturing technology for various applications. The custom PCB ranges from very thin for portable application to very thick for power application. Despite conventional understanding and prior studies, some of the failures were not explained. This study reviews three failure problems for QFN, WCSP and BGA packages by characterizing the properties of custom PCB materials by layer removal process. Due to layup …

Parametric Study Of Aerodynamic Performance Of An Airfoil With Active Circulation Control Using Leading Edge Embedded Cross-Flow Fan, M.A. Qayyum Mazumder

Doctoral Dissertations and Master's Theses

A concept of a cross-flow fan (CFF) embedded near the leading edge of an airfoil to actively control the boundary layer for lift and thrust enhancement has been proposed. The design places a cross-flow fan near the leading edge of an airfoil and flow is drawn in from the pressure side of the airfoil, energized and expelled out to the suction side near the leading edge. This CFF system simulates the active boundary layer control by blowing commercial computational fluid dynamics (CFD) code ANSYS Fluent is employed to perform 2-D calculations based on various parameters of the CFF and compared …

Development To A Flexible Surface Acoustic Wave Sensor For Strain Sensing, Neha Vedavathi Ramachandran

Doctoral Dissertations and Master's Theses

Surface acoustic wave (SAW) sensors have increasing demand in structural health monitoring due to their passive, variable bandwidth, reliable life-cycle, high accuracy, small size, and light nature. SAW sensors can not only provide the static states of the structural system, such as temperature and pressure but also enable continuous real-time monitoring of dynamic states including strains. SAW sensors are generally fabricated with a rigid piezoceramic substrate, incapable of adapting to highly curved surfaces or flexible objects. The ongoing demands of sensor adaptability with flexible substrates, which is also capable of wireless monitoring, is the basis of the research that can …

Biofidelic Piezoresistive Sandwich Composites, Nengda Jiang

Doctoral Dissertations and Master's Theses

Silicone based biofidelic surrogates are being used in many biomedical applications; e.g. to understand the body injury mechanisms, evaluate protective equipment like helmets and armors. Apart from matching the mechanical behavior of bodily tissues, there is an increasing requirement for these materials to be electrically conductive and piezoresistive to facilitate direct instrumentation. Carbon nanotubes (CNTs) are a possible filler to impart electrical conductivity and piezoresistivity to silicone biofidelic materials. A sandwich structure of silicone and CNT sheet, comprising two dielectric facesheets and a highly conductive core layer has added advantages of raising the dielectric permittivity and suppressing dielectric loss.

In …

The Development And Validation Of Sinatra: A Three-Dimensional Direct Simulation Monte Carlo (Dsmc) Code Written In Object-Oriented C++ And Performed On Cartesian Grids, David Matthew Galvez

Master's Theses

The field of Computational Fluid Dynamics (CFD) primarily involves the approximation of the Navier-Stokes equations. However, these equations are only valid when the flow is considered continuous such that molecular interactions are abundant and predictable. The Knudsen number, $Kn$, which is defined as the ratio of the flow's mean free path, $\lambda$, to some characteristic length, $L$, quantifies the continuity of any flow, and when this parameter is large enough, alternative methods must be employed to simulate gases. The Direct Simulation Monte Carlo (DSMC) method is one which simulates rarefied gas flows by directly simulating the particles that compose the …

Plume Contamination Measurements Of An Additively-Printed Gox/Abs Hybrid Thruster, David A. Brewer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis examines the impact of the physical contamination on optical surfaces of spacecraft by an ABS/GOX thruster. Plume contamination presents a significant operational hazard for spacecraft solar arrays and thermal control surfaces can lead to decreased power production and increased spacecraft temperatures. Historically, due to the lack of a reliable, on-demand, and multiple-use ignition methodology, hybrid rockets have never been previously considered for in-space propulsion. Recent advancements in hybrid rocket technologies, have made hybrid systems feasible for in space propulsion. However, prior to this study no research had ever been performed with regard to plume contamination effects due to …

Determination Of Takeoff And Landing Distances Using An Ipad Performance Application For The Diamond Da40, Tyler A. Babb, Christina Hiers

International Journal of Aviation, Aeronautics, and Aerospace

All pilots are required to calculate aircraft performance parameters prior to flight. This includes takeoff and landing distances. Traditionally, pilots in training have planned for takeoff and landing performance using paper charts provided by the manufacturer. However, professional pilots use devices such as Flight Management Systems (FMS), Electronic Flight Bag (EFB) applications, or on-board performance computers (OPC) to make such calculations. During primary flight training, student pilots could make performance calculations with proper software, similar to the method they will typically use at the professional level. Recently an iPad application was released which can calculate numerous performance parameters for specific …

A Non-Equilibrium Molecular Dynamics Study Of The Effects Of Helium Bubbles On The Thermal Conductivity Of Zrc, Tate Shorthill

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Zirconium carbide (ZrC) has been proposed as a potential improvement to nuclear fuel cladding. As such, it is important to characterize its physical properties, particularly those relating to thermal energy transport. Reactor conditions are known to damage fuel microstructure over time. While research has been conducted on undamaged and damaged ZrC, some areas of interest remain. Fission products, such as helium, can accumulate in pores within the fuel microstructure. Such a case has yet to be characterized in ZrC fuel cladding.

A non-equilibrium molecular dynamics model was developed to characterize the thermal properties of ZrC. Fourier’s Law allows the thermal …

Experiments Of Propeller-Induced Flow Effects On A Low-Reynolds-Number Wing, Gavin K. Ananda, Robert Deters, Michael S. Selig

Publications

Novel findings are discussed in this paper that will be especially beneficial to designers and modelers of small-scale unmanned air vehicles and high-altitude long-endurance vehicles that both operate at low Reynolds numbers (Re = 50,000-300,000). Propeller-induced Oow effects in both tractor and pusher configurations on a recta ngular wing using the Wortmann FX 63-137 airfoil (a common low-Reynolds-number high-lift airfoil) are presented in this paper . Significant performance benefits can be found for a wing in the tractor configuration. Experiments, including trip tests and upper-surface oil Dow visualization, show and verify that the propeller slipstream induces early transition to turbulent …

Design Survey Of Laminated Composite I-Beam, Mrinmoy Saha

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Composite I-beams are popular for high-strength low-weight applications. Learning the macro-mechanics and designing the composite I-beam properly are necessary. In this report, a design overview of the composite I-beam is discussed which is based on classical lamination theory where it includes the homogenization approach, the plane stress assumption and the Kirchhoff hypothesis. Using these assumptions, a method was developed to come up with the effective material properties of a beam. Formulas to calculate maximum deflection and maximum bending stress and shear stress and the stress concentration at the connection of web-flange are discussed which describe ways for designing and manufacturing …

Characterization Of A Turbulent Boundary Layer In Open Channel Flow Using Particle Image Velocimetry, Mathew James Stanek

Electronic Theses and Dissertations

Turbulent boundary layers are influential in numerous applications (e.g. naval architecture, ocean engineering, sediment transport, etc.), yet considerable knowledge gaps still exist. Boundary layers are regions where transfer of mass, momentum, energy, and heat occur within the interface between a fluid and a solid, or between two fluids. Utilization of optical flow measurement techniques to measure the velocity field with high spatial resolution enables non-intrusive investigation of the complex fluid dynamics of boundary layers. In this study two-dimensional Particle Image Velocimetry was employed to investigate, primarily, the overlap layer of a turbulent boundary layer developed in the recirculating flume facility …

Fuel Flow Reduction Impact Analysis Of Drag Reducing Film Applied To Aircraft Wings, Damon Resnick, Chris Donlan, Nimish Sakalle, Cody Pinkerman

SMU Data Science Review

In this paper, we present an analysis of flight data in order to determine whether the application of the Edge Aerodynamix Conformal Vortex Generator (CVG), applied to the wings of aircraft, reduces fuel flow during cruising conditions of flight. The CVG is a special treatment and film applied to the wings of an aircraft to protect the wings and reduce the non-laminar flow of air around the wings during flight. It is thought that by reducing the non-laminar flow or vortices around and directly behind the wings that an aircraft will move more smoothly through the air and provide a …

U.S. Government Aviation Safety Information Resources, Bert Chapman

Libraries Faculty and Staff Presentations

Presentation covering U.S. Government aviation safety information resources. Topics addressed include U.S. laws,legislation, regulations, court cases, information resources from agencies such as the Federal Aviation Administration, Transportation Security Administration, National Aeronautics and Space Administration, congressional aviation oversight committees and congressional support agencies including the Congressional Budget Office, Congressional Research Service, and Government Accountability Office.

Molecular Dynamics Simulation Study On The Possible Factors Affecting Stability Of Ods Steel, M. Mustafa Azeem, Zhongyu Li, Qingyu Wang, Abid Hussian

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Oxide-dispersed-strengthened (ODS) steel has excellent mechanical, thermodynamic and radiation resistant properties, which makes it an important candidate material for high-Temperature reactors applications. Radiation stability of oxide is very important to study at the atomic level. In present case molecular dynamics (MD) simulation is used to study stabilities of Y₂O₃ particles in ODS steel as a function of particle sizes. The size dependence is obvious for particle sizes larger than 2.8 nm. Furthermore, the stabilities depend on charges of Y and O atoms.

Breaking Down Traditional Classroom Walls And Studying Spacesuits Abroad, Ryan L. Kobrick, Jessica Mckee Ph.D., Sue A. Macchiarella, Angelica Gould

Publications

The spacesuit curriculum under development by the Spacesuit Utilization of Innovative Technology Laboratory (S.U.I.T. Lab) in the Spaceflight Operations program of the Applied Aviation Sciences Department at Embry-Riddle Aeronautical University has the unique challenge of educating non-engineering students about extremely technical space systems, highlighted by spacesuits. CSO 399: “Spacesuits and Human Spaceflight Operations” course, taught in Greece each summer, introduces students to human spaceflight topics. This unique offering takes advantage of the clear water visibility in the Aegean Sea with practical underwater demonstrations of space operations. Students live in confined quarters on a sailboat for two weeks to simulate operations …

Increasing Spaceflight Analogue Mission Fidelity By Standardization Of Extravehicular Activity Metrics Tracking And Analysis, Ryan L. Kobrick, Nicholas Lopac, Jenifer Schuman, John French, Tatsunari Tomiyama

Publications

Spaceflight analogues include human simulations that attempt to match as many variables of a real mission as possible, but here on Earth and at a fraction of the cost each having limitations. The goal of this Embry-Riddle Aeronautical University (ERAU) Spacesuit Utilization of Innovative Technology Laboratory (S.U.I.T. Lab) research is to improve simulation fidelity through Extravehicular Activity (EVA) data collection, analysis, and feedback, which will help humanity prepare for destinations such as the Moon or Mars. Investigated EVA metrics, physical and biomedical, are based on the identified NASA Human Research Roadmap research gaps related to the risk of injury and …

Spacesuit Range Of Motion Investigations Using Video And Motion Capture Systems At Spaceflight Analogue Expeditions And Within The Erau S.U.I.T. Lab, Ryan L. Kobrick, Nicholas Lopac, Jenifer Schuman, Chase Covello, John French, Angelica Gould, Maximilian Meyer, Theodore Southern, Jazmyne Lones, Joshua W. Ehrlich

Publications

The Embry-Riddle Aeronautical University (ERAU) Spacesuit Utilization of Innovative Technology Laboratory (S.U.I.T. Lab) is dedicated to the pursuit of advancing human spaceflight by contributing to spacesuit and operations research with experiential programs for students. A significant portion of the S.U.I.T. Lab’s portfolio is dedicated to the design and execution of spacesuit range of motion (ROM) investigations using video and motion capture systems. ROM biomechanical angles were measured using these techniques in conjunction with developing protocols for both simulated extravehicular activity suits at spaceflight analogue expeditions, and on ERAU campus with Final Frontier Design (FFD) intravehicular activity pressure suits. Designing protocols …

A Comparison Of The Strengths And Weaknesses Of Small-Format Aerial Photography Platforms, Jeremy W. Aber, Tyler A. Babb, Douglas E. Campbell, Kevin M. Corns

International Journal of Aviation, Aeronautics, and Aerospace

The demand for small-format aerial photography continues to grow in large part due to the rapid adoption of unmanned aerial vehicles (UAVs). Prior to the explosion of UAV use, this kind of photography was collected using older technologies such as tethered kites and blimps. Due to the increased demand for aerial imagery, this article looks at four platforms commonly used to collect small-format aerial imagery: multi-rotor UAVs, fixed-wing UAVs, kites, and blimps. Practical use considerations are explored, including characteristics of flight and operation, atmospheric and site factors, imaging sensors and costs, and regulatory limitations.

Each of the four categories of …

Considerations For Atmospheric Measurements With Small Unmanned Aircraft Systems, Jamey D. Jacob, Phillip B. Chilson, Adam L. Houston, Suzanne Weaver Smith

Mechanical Engineering Faculty Publications

This paper discusses results of the CLOUD-MAP (Collaboration Leading Operational UAS Development for Meteorology and Atmospheric Physics) project dedicated to developing, fielding, and evaluating integrated small unmanned aircraft systems (sUAS) for enhanced atmospheric physics measurements. The project team includes atmospheric scientists, meteorologists, engineers, computer scientists, geographers, and chemists necessary to evaluate the needs and develop the advanced sensing and imaging, robust autonomous navigation, enhanced data communication, and data management capabilities required to use sUAS in atmospheric physics. Annual integrated evaluation of the systems in coordinated field tests are being used to validate sensor performance while integrated into various sUAS platforms. …

Electro-Drop Bouncing In Low-Gravity, Erin Stivers Schmidt

Dissertations and Theses

We investigate the dynamics of spontaneous jumps of water drops from electrically charged superhydrophobic dielectric substrates during a sudden step reduction in gravity level. In the brief free-fall environment of a drop tower, with a non-homogeneous external electric field arising due to dielectric surface charges (with surface potentials 0.4-1.8 kV), body forces acting on the jumped drops are primarily supplied by polarization stress and Coulombic attraction instead of gravity. This electric body force leads to a drop bouncing behavior similar to well-known phenomena in 1-g₀, though occurring for much larger drops (~0.5 mL). We show a simple …

Design And Performance Estimation Of A Low-Reynolds Number Unmanned Aircraft System, Sean Lauderdale King

LSU Master's Theses

The purpose of this thesis is to conceptually design a fixed-wing unmanned aircraft systems (UAS) with a higher flight-time and top stable speed than comparable systems. The vehicle adheres to specifications derived from the client, the market, and the Federal Aviation Administration (FAA). To broadly meet these requirements, the vehicle must fly for a minimum of three hours, return to the original flight path quickly if perturbed, and must be hand-launched. The vehicle designed must also have a large potential center of gravity movement to allow for customization of the planform and client customization.

An iterative design process was used …

A Computational Fluid Dynamics Study On The Aerodynamic Performance Of Ram-Air Parachutes, Angelo A. Fonseca Pazmiño

Doctoral Dissertations and Master's Theses

The modeling of a ram-air parachute presents challenges in the prediction of the inflight geometry, as there is a strong interaction between the flow field and parachute structure. This thesis presents the development of a CAD design and CFD methodology to the simulation of ram-air parachutes in steady-state conditions. Starting from a 2D rib drawing, methods were developed to approximate the 3D geometry and efficiently model the parachute as a rigid and impermeable body. The use of distortions was implemented on a 2D, pseudo-2D, and 3D model to enhance their behavior during a real flight. The SST turbulence model was …