Aerial Rendezvous Between An Unmanned Air Vehicle And An Orbiting Target Vehicle,
2011
Brigham Young University - Provo
Aerial Rendezvous Between An Unmanned Air Vehicle And An Orbiting Target Vehicle, Mark Andrew Owen
Theses and Dissertations
In this thesis we develop methods that facilitate an aerial rendezvous between two air vehicles. The objective of this research is to produce a method that can be used to insert a miniature air vehicle behind a rendezvous vehicle and then track that vehicle to enable a visual rendezvous. For this research we assume the rendezvous vehicle is following a relatively stable and roughly elliptical orbit. Path planners and controllers have been developed that can be used to effectively intercept the rendezvous vehicle by inserting the MAV onto the orbit of interest. A method for planning and following time-optimal Dubins …
A Novel Solid Oxide Redox Flow Battery For Grid Energy Storage,
2011
University of South Carolina - Columbia
A Novel Solid Oxide Redox Flow Battery For Grid Energy Storage, Nansheng Xu, Xue Li, Xuan Zhao, John B. Goodenough, Kevin Huang
Faculty Publications
In this work we report proof-of-concept of a novel redox flow battery consisting of a solid oxide electrochemical cell (SOEC) integrated with a redox-cycle unit. The charge/discharge characteristics were explicitly observed by operating between fuel cell and electrolysis modes of the SOEC along with “in-battery” generation and storage of H2 realized by an in situ closed-loop reversible steam-metal reaction in the redox-cycle unit. With Fe/FeO as the redox materials, the new storage battery can produce an energy capacity of 348 Wh/kg-Fe and round-trip efficiency of 91.5% over twenty stable charge/discharge cycles. This excellent performance combined with robustness, environmental friendliness …
Direct Numerical Simulation Of Hypersonic Turbulent Boundary Layers. Part 4. Effect Of High Enthalpy,
2011
Missouri Unviersity of Science and Technology
Direct Numerical Simulation Of Hypersonic Turbulent Boundary Layers. Part 4. Effect Of High Enthalpy, L. (Lian) Duan, M. P. Martín
Mechanical and Aerospace Engineering Faculty Research & Creative Works
In this paper we present direct numerical simulations (DNS) of hypersonic turbulent boundary layers to study high-enthalpy effects. We study high-and low-enthalpy conditions, which are representative of those in hypersonic flight and ground-based facilities, respectively. We find that high-enthalpy boundary layers closely resemble those at low enthalpy. Many of the scaling relations for low-enthalpy flows, such as van-Driest transformation for the mean velocity, Morkovin's scaling, and the modified strong Reynolds analogy hold or can be generalized for high-enthalpy flows by removing the calorically perfect-gas assumption. We propose a generalized form of the modified Crocco relation, which relates the mean temperature …
A Study Of Solder Joint Failure Criteria,
2011
California Polytechnic State University - San Luis Obispo
A Study Of Solder Joint Failure Criteria, Jianbiao Pan, Julie Silk
Industrial and Manufacturing Engineering
One of the challenges in an experimental study of solder joint reliability is to determine when cracks occur in a solder joint or when a solder joint fails. Cracks in a real solder joint are difficult to identify using an X-Ray system. Cross-sectioning and scanning electron microscopy (SEM) is a destructive method. A common non-destructive test method is to monitor resistance increase in a solder joint or a daisy-chain. However, no scientific research has been done in establishing the relationship between the crack area of an interconnection and the change in resistance of the interconnection. This paper proposes a method …
Synthesis, Structural, Optical And Mechanical Characterization Of Srb2O4 Nanorods,
2011
University of South Carolina - Columbia
Synthesis, Structural, Optical And Mechanical Characterization Of Srb2O4 Nanorods, Rui Li, Lihong Bao, Xiaodong Li
Faculty Publications
Single crystalline strontium borate (SrB2O4) nanorods were synthesized for the first time via a facile sol–gel route at low temperature. The SrB2O4 nanorods have a good crystalline nature with the growth direction along the [511] orientation and they are transparent from the ultraviolet to the visible regimes. Nanoscale three-point bending tests were performed directly on individual nanorods to probe their mechanical properties using an atomic force microscope. The elastic modulus of SrB2O4 nanorods was measured to be 158.2 ± 2.8 GPa, exhibiting a significant increase compared with other borate nanostructures …
Automated Flow Path Design Optimization Using Mesh Morphing,
2011
Brigham Young University - Provo
Automated Flow Path Design Optimization Using Mesh Morphing, William Dennis Gough
Theses and Dissertations
The use of CAD models and CFD analysis has become an essential part of fluid flow design. To reduce the time spent determining a design, optimization frameworks have been implemented to automate the process. Mesh morphing has been implemented within these frameworks to further reduce the time needed. While optimization methods have been developed to optimize a fluid flow path, the optimum design needs to be recreated in a CAD model. A method has been developed which eliminates the need to recreate the optimal results in CAD. This is accomplished by using mesh morphing, CAD and CFD together in an …
Technical Note: Friction Factor Diagrams For Pipe Flow,
2011
Technological University Dublin
Technical Note: Friction Factor Diagrams For Pipe Flow, Jim Mcgovern
Articles
This technical note describes diagrams of friction factor for pipe flow that have been prepared using, mainly, the equations that Lewis Moody used to prepare his famous diagram in 1944. The preparation of the new diagrams was prompted by the need for vector graphics versions that could be used for teaching purposes and that could be distributed freely to students and others under a Creative Commons Attribution-Share-Alike license. Using a structure very similar to that of Moody's diagram, variants with the Darcy friction factor and the Fanning friction factor have been prepared. In addition, variants have been prepared that include …
Effect Of Gold Content On The Reliability Of Snagcu Solder Joints,
2011
California Polytechnic State University - San Luis Obispo
Effect Of Gold Content On The Reliability Of Snagcu Solder Joints, Jianbiao Pan, J. Silk, M. Powers, P. Hyland
Industrial and Manufacturing Engineering
Electroplated Ni/Au over Cu is a popular metallization for printed circuit board finish as well as for component leads, especially wire-bondable high-frequency packages, where the gold thickness requirement for wire bonding is high. The general understanding is that less than 3 wt% of Au is acceptable in SnPb solder joints. However, little is known about the effect of Au content on the reliability of SnAgCu solder joints. The purpose of this paper is to determine the acceptable level of Au in SAC305 solder joints. Three different package platforms with different Au thicknesses were assembled on boards with two different Au …
A Multi-Regulator Sliding Mode Control Strategy For Output-Constrained Systems,
2011
Cleveland State University
A Multi-Regulator Sliding Mode Control Strategy For Output-Constrained Systems, Hanz Richter
Mechanical Engineering Faculty Publications
This paper proposes a multi-regulator control scheme for single-input systems, where the setpoint of a regulated output must be changed under the constraint that a set of minimum-phase outputs remain within prescribed bounds. The strategy is based on a max–min selector system frequently used in the aerospace field. The regulators used for the regulated and limited outputs are of the sliding mode type, where the sliding variable is defined as the difference between an output and its allowable limit. The paper establishes overall asymptotic stability, as well as invariance properties leading to limit protection. The design methodology is illustrated with …
Exploration Of Nde Properties Of Amb Supported Rotors For Structural Damage Detection,
2011
Cleveland State University
Exploration Of Nde Properties Of Amb Supported Rotors For Structural Damage Detection, Jerzy T. Sawicki, Dmitry L. Storozhev, John D. Lekki
Mechanical Engineering Faculty Publications
Recent advancements in actuator technology, power electronics, sensors, and signal processing have created a rapid development of smart machine technologies for rotating machinery. Ranging from machine condition monitoring and diagnostics to full active control of machine behavior, the integration of electrical and computer systems has produced significant advances in machine performance and reliability. Magnetic bearings are a typical mechatronics product. The hardware is composed of mechanical components combined with electronic elements such as sensors and power amplifiers and an information processing part, usually in the form of a microprocessor. In addition, an increasingly important part is software, which specifies the …
Effective Approach For Estimating Turbulence-Chemistry Interaction In Hypersonic Turbulent Boundary Layers,
2011
Missouri Unviersity of Science and Technology
Effective Approach For Estimating Turbulence-Chemistry Interaction In Hypersonic Turbulent Boundary Layers, L. (Lian) Duan, M. P. Martín
Mechanical and Aerospace Engineering Faculty Research & Creative Works
An effective approach for estimating turbulence-chemistry interaction in hypersonic turbulent boundary layers is proposed, based on "laminar- chemistry" Reynolds-averaged Navier-Stokes mean flow solutions. The approach combines an assumed probability density function with a temperature fluctuation scaling, which provides the second moment for specifying the shape of the probability density function. As a result, the effects of temperature fluctuation on chemical production rates can be estimated without solving an additional moment evolution equation. The validity of this method is demonstrated using direct-numerical-simulation data. This approach can be used to identify regions with potentially significant turbulence-chemistry interaction in hypersonic boundary layers and …
Effectiveness Of Group Kickboxing As A Means To Improve Gait And Balance In Individuals With Ms,
2011
University of Dayton
Effectiveness Of Group Kickboxing As A Means To Improve Gait And Balance In Individuals With Ms, Kurt Jackson, Kimberly Edginton Bigelow, Christina Cooper, Harold L. Merriman
Mechanical and Aerospace Engineering Faculty Publications
In recent years, there has been a particular emphasis on identifying and delivering appropriate therapeutic interventions that address the significant balance and gait impairments that affect individuals with multiple sclerosis (MS). Group interventions implemented in community settings have been especially of interest, including tai chi classes. Recently, the authors conducted a preliminary study to examine whether group kick-boxing, which requires more vigorous movements, might be a feasible intervention. Initial findings showed promise and led the authors to pursue a more rigorous follow-up study, with the objective of determining whether a 5-week group kickboxing class improved clinical measures of balance and …
Innovative Manufacturing Process For Defect Free, Affordable, High Pressure, Thin Walled, Hydraulic Tubing,
2011
Loyola Marymount University
Innovative Manufacturing Process For Defect Free, Affordable, High Pressure, Thin Walled, Hydraulic Tubing, W. Miranda, G. Takiguchi, T. Shimabukuro, L. Mclennan, C. Agajanian, L. Quintero, D. Mismar, J. Abdulla, C. Andrews, M. Hahn, E. Fodran, E. W. Lee, H. Garmestani, R. D. Conner, D. Brick, J. Ogren, Omar S. Es-Said
Mechanical Engineering Faculty Works
Various thermo-mechanical processes were performed on a standard and a low oxygen content Ti-6Al-4V alloy. Testing was performed to determine whether it was possible to achieve a combination of tensile properties comparable to those of Ti-3Al-2.5V by means of cold working and annealing Ti-6Al-4V from a thickness of 0.671 cm (0.264 in.) to that between 0.081 and 0.094 cm (0.032-0.037 in.), which had never been carried out before. The resulting mechanical properties of this study were compared to the mechanical properties of Ti-3Al-2.5V to determine whether Ti-6Al-4V could be used as a suitable replacement for hydraulic tubing applications. The optimum …
On The Distortion And Warpage Of 7249 Aluminum Alloy After Quenching And Machining,
2011
Loyola Marymount University
On The Distortion And Warpage Of 7249 Aluminum Alloy After Quenching And Machining, N. Keleshian, R. Kyser, J. Rodriquez, C. Cueva, V. Vega, E. W. Lee, J. Ogren, Omar S. Es-Said
Mechanical Engineering Faculty Works
The objective of this study is to determine the effect of solution treatment temperature, quenching media, and various machining sequences on the warpage behavior of aluminum 7249 alloy aged to T6 and T7' tempers. Large extrusions of 7249 aluminum alloy with fins were cut into 108 "T" sections. The samples were solution-treated, aged, and machined. Three solution temperatures (445, 474, and 505 A degrees C), two quenching media (water and 20% polyalkylene glycol), two aging treatments (T6 and T7'), and three machine sequences were used. The flatness of the samples was measured on the surfaces orthogonal to the z-axis. Three …
Effect Of Stretch Orientation And Rolling Orientation On The Mechanical Properties Of 2195 Al-Cu-Li Alloy,
2011
Loyola Marymount University
Effect Of Stretch Orientation And Rolling Orientation On The Mechanical Properties Of 2195 Al-Cu-Li Alloy, Omar S. Es-Said, C. J. Parrish, C. A. Bradberry, J. Y. Hassoun, R. A. Parish, A. Nash, N. C. Smythe, K. N. Tran, T. Ruperto, E. W. Lee, D. Mitchell, C. Vinquist
Mechanical Engineering Faculty Works
Sheets of 2195 aluminum-lithium alloy were solution-treated at 507 A degrees C for 30 min. One set was stretched to 3-5% in the 0A degrees, 45A degrees, and 90A degrees angle with respect to the original rolling direction. Two other sets were rolled 6% reduction in thickness and 24% reduction in thickness in the 0A degrees, 45A degrees, and 90A degrees angle with respect to the original rolling direction. All specimens were aged at 143 A degrees C for 36 h. A second group of samples was rolled at 24 and 50% reduction in thickness after a solution treatment of …
2011 (Fall) Ensi Informer Magazine,
2011
Morehead State University
2011 (Fall) Ensi Informer Magazine, Morehead State University. Engineering Sciences Department
ENSI Informer Magazine Archive
The ENSI Informer Magazine published in the fall of 2011.
Transient Finite Element Analysis Of A Base Excited Frame On A Six Dof Motion Simulator To Simulate Wave Slamming,
2011
Old Dominion University
Transient Finite Element Analysis Of A Base Excited Frame On A Six Dof Motion Simulator To Simulate Wave Slamming, Matthew Douglas Davis
Mechanical & Aerospace Engineering Theses & Dissertations
High speed performance crafts are subjected to repeated impact loads in open seas. In this study, an attempt is made to investigate the dynamic response of onboard equipment under an impact environment generated by a 6 degree-of-freedom (DOF) motion simulator. An aluminum frame is used to represent onboard equipment, which is mounted on the 6 DOF motion simulator at various orientations and with varying amounts of additional weight. A series of 15 single-axis drop tests are conducted with the DOF motion simulator to study the effects of these impact loads on the onboard equipment. The test data is analyzed to …
Study Of The Role Of Pressure Relaxation In Inviscid, Incompressible Flows,
2011
Old Dominion University
Study Of The Role Of Pressure Relaxation In Inviscid, Incompressible Flows, Jonathan Strzelec
Mechanical & Aerospace Engineering Theses & Dissertations
This thesis has investigated the role of pressure relaxation in inviscid, incompressible flows. A modified form of the classical Bernoulli equation was developed from a vector form of the Navier-Stokes equation which includes pressure relaxation and bulk viscosity. This modified Bernoulli equation was utilized to compare two-dimensional potential flow pressure distributions over a sphere, cylinder, backward and forward facing steps. Finally, the modified Bernoulli equation was utilized to compare the theoretical bounding free streamline to an experimentally observed free streamline over a knife edge. Results of these comparisons show that the classical form of the Bernoulli equation can over-predict the …
Droplet Behavior In Dense, Low Velocity Aerosols,
2011
Marquette University
Droplet Behavior In Dense, Low Velocity Aerosols, Alexander Polley
Master's Theses (2009 -)
Rapid compression machines (RCM) are laboratory devices used to measure gas-phase fuel reactivity at conditions relevant to combustion engines. Test mixtures are generally prepared by rapidly compressing a gas phase fuel+oxidizer+diluent mixture to high pressure and temperature (e.g., 10-50 bar, 650-1000 K). It is extremely challenging to utilize diesel-relevant liquid fuels in these devices due to their involatility. One proposed method involves the delivery of an aerosol of suspended fuel droplets (∼ 0.1 mLfuel/Lgas at stoichiometric fuel loading) to the machine. The compression stroke of the RCM subsequently heats the gas phase of the aerosol thereby achieving …
Investigation Of Aluminum Equation Of State Generation,
2011
Marquette University
Investigation Of Aluminum Equation Of State Generation, Aaron Ward
Master's Theses (2009 -)
There are many forms and methods to construct equations of state, EOSs. These methods are usually tailored for the particular problem of interest. Here, the EOSs of interest are those used in modeling shock responses. These EOSs cover a wide range of physical characteristics such as detonation and explosions, armor and anti-armor materials, and space structures protection. Aluminum will be the primary focus of this work. Aluminum was chosen because it has been studied in great length in the shock regime and is a common component in shock experiments and space type vehicles.
