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Aerospace Engineering

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2009

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Articles 1 - 20 of 20

Full-Text Articles in Mechanical Engineering

Project: F.U.N.B.O.E. (Follow-Up Nucleate Boiling On-Flight Experiment), Getaway Special Team 2009 Oct 2009

Project: F.U.N.B.O.E. (Follow-Up Nucleate Boiling On-Flight Experiment), Getaway Special Team 2009

Education and Outreach

No abstract provided.


Sixth Grade Lesson Plan: Heat Moves, Getaway Special Team 2009 Oct 2009

Sixth Grade Lesson Plan: Heat Moves, Getaway Special Team 2009

Education and Outreach

No abstract provided.


Third Grade Lesson Plan: Where Does Heat Come From?, Getaway Special Team 2009 Oct 2009

Third Grade Lesson Plan: Where Does Heat Come From?, Getaway Special Team 2009

Education and Outreach

No abstract provided.


Reinforcement-Learning-Based Output-Feedback Control Of Nonstrict Nonlinear Discrete-Time Systems With Application To Engine Emission Control, Peter Shih, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier Oct 2009

Reinforcement-Learning-Based Output-Feedback Control Of Nonstrict Nonlinear Discrete-Time Systems With Application To Engine Emission Control, Peter Shih, Brian C. Kaul, Jagannathan Sarangapani, J. A. Drallmeier

Electrical and Computer Engineering Faculty Research & Creative Works

A novel reinforcement-learning-based output adaptive neural network (NN) controller, which is also referred to as the adaptive-critic NN controller, is developed to deliver the desired tracking performance for a class of nonlinear discrete-time systems expressed in nonstrict feedback form in the presence of bounded and unknown disturbances. The adaptive-critic NN controller consists of an observer, a critic, and two action NNs. The observer estimates the states and output, and the two action NNs provide virtual and actual control inputs to the nonlinear discrete-time system. The critic approximates a certain strategic utility function, and the action NNs minimize the strategic utility …


Fifth Grade Lesson Plan: Solid, Liquid, And Gas, Getaway Special Team 2009 Oct 2009

Fifth Grade Lesson Plan: Solid, Liquid, And Gas, Getaway Special Team 2009

Education and Outreach

No abstract provided.


Phase Change Mechanisms During Femtosecond Laser Pulse Train Ablation Of Nickel Thin Films, Xin Li, Lan Jiang, Hai-Lung Tsai Sep 2009

Phase Change Mechanisms During Femtosecond Laser Pulse Train Ablation Of Nickel Thin Films, Xin Li, Lan Jiang, Hai-Lung Tsai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The mechanisms of nickel thin films irradiated by femtosecond laser pulse trains are studied by a model using molecular dynamics simulations and two-temperature model. It is found that the pulse train technology can change energy transport and corresponding phase change processes. Compared with single pulse ablation at the same total fluence, the pulse trains lead to (1) lower ablation rate with more and smaller uniform nanoparticles, (2) higher film surface temperatures and longer thermalization time, (3) much lower electron thermal conductivity that can further control heat-affected zone, (4) significantly smaller film compressive stresses and tensile stresses which reduce microcracks, and …


Evaluation Of Direct Diode Laser Deposited Stainless Steel 316l On 4340 Steel Substrate For Aircraft Landing Gear Application, Tian Fu, Todd E. Sparks, Frank W. Liou, Joseph William Newkirk, Zhiqiang Fan, Syamala Rani Pulugurtha, Jianzhong Ruan, Hsin-Nan Chou Aug 2009

Evaluation Of Direct Diode Laser Deposited Stainless Steel 316l On 4340 Steel Substrate For Aircraft Landing Gear Application, Tian Fu, Todd E. Sparks, Frank W. Liou, Joseph William Newkirk, Zhiqiang Fan, Syamala Rani Pulugurtha, Jianzhong Ruan, Hsin-Nan Chou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

300M steel is used extensively for aircraft landing gears because of its high strength, ductility and toughness. However, like other high-strength steels, 300M steel is vulnerable to corrosion fatigue and stress corrosion cracking, which can lead to catastrophic consequences in the landing gear. Stainless steels offer a combination of corrosion, wear, and fatigue properties. But for an aircraft landing gear application a higher surface hardness is required. A laser cladding process with fast heating and cooling rates can improve the surface hardness. AISI 4340 steel is used as a lower cost alternative to 300M due to its similar composition. In …


A New State Observer And Flight Control Of Highly Maneuverable Aircraft, S. N. Balakrishnan, Ming Xin Jun 2009

A New State Observer And Flight Control Of Highly Maneuverable Aircraft, S. N. Balakrishnan, Ming Xin

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this paper, a new nonlinear observer (θ-D observer) is proposed to estimate the feedback states for optimal control of a highly maneuverable aircraft. This observer is derived by constructing the dual of a recently developed nonlinear optimal control technique-known as the θ-D technique. The θ-D optimal control approach provides an approximate closed-form solution to the Hamilton-Jacobi-Bellman (HJB) equation. An optimal flight controller using this technique is designed for a highly maneuverable aircraft operating at high angle of attack where the θ-D observer is employed to estimate the states for feedback. The structure of this observer is similar to the …


A Microfabricated Segmented-Involute-Foil Regenerator For Enhancing Reliability And Performance Of Stirling Engines: Phase Iii Final Report For The Radioisotope Power Conversion Technology Nra Contract Nas3-03124, Mounir B. Ibrahim, David Gedeon, Gary Wood, Jeffrey Mclean Jun 2009

A Microfabricated Segmented-Involute-Foil Regenerator For Enhancing Reliability And Performance Of Stirling Engines: Phase Iii Final Report For The Radioisotope Power Conversion Technology Nra Contract Nas3-03124, Mounir B. Ibrahim, David Gedeon, Gary Wood, Jeffrey Mclean

Mechanical Engineering Faculty Publications

Under Phase III of NASA Research Announcement contract NAS3-03124, a prototype nickel segmented-involute-foil regenerator was microfabricated and tested in a Sunpower Frequency-Test-Bed (FTB) Stirling convertor. The team for this effort consisted of Cleveland State University, Gedeon Associates, Sunpower Inc. and International Mezzo Technologies. Testing in the FTB convertor produced about the same efficiency as testing with the original random-fiber regenerator. But the high thermal conductivity of the prototype nickel regenerator was responsible for a significant performance degradation. An efficiency improvement (by a 1.04 factor, according to computer predictions) could have been achieved if the regenerator was made from a low-conductivity …


Multiscale Modeling Of Impact On Heterogeneous Viscoelastic Solids With Evolving Microcracks, Flavio V. Souza Apr 2009

Multiscale Modeling Of Impact On Heterogeneous Viscoelastic Solids With Evolving Microcracks, Flavio V. Souza

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Multiscale computational techniques play a major role in solving problems related to viscoelastic composite materials due to the complexities inherent to these materials. In the present work, a numerical procedure for multiscale modeling of impact on heterogeneous viscoelastic solids containing evolving microcracks is proposed in which the (global scale) homogenized viscoelastic incremental constitutive equations have the same form as the local scale viscoelastic incremental constitutive equations, but the homogenized tangent constitutive tensor and the homogenized incremental history dependent stress tensor depend on the amount of damage accumulated at the local scale. Furthermore, the developed technique allows the computation of the …


Microgravity Experiments For The Iss, Justin Koeln, Jan Sojka Mar 2009

Microgravity Experiments For The Iss, Justin Koeln, Jan Sojka

Posters

The Get Away Special (GAS) team is a microgravity research team known for leading Utah State University to the impressive distinction of flying more experiments in space than any other university in the world. The following experiments were designed by the GAS team after receiving the opportunity to develop and experiment to be performed by a Space Flight Participant aboard the International Space Station (ISS).


Computational And Experimental Investigation Of The Flow Structure And Vortex Dynamics In The Wake Of A Formula 1 Tire, John Axerio, Gianluca Iaccarino, Emin Issakhanian, Chris Elkins, John Eaton Jan 2009

Computational And Experimental Investigation Of The Flow Structure And Vortex Dynamics In The Wake Of A Formula 1 Tire, John Axerio, Gianluca Iaccarino, Emin Issakhanian, Chris Elkins, John Eaton

Mechanical Engineering Faculty Works

The flowfield around a 60% scale stationary Formula 1 tire in contact with the ground in a closed wind tunnel was examined experimentally in order to assess the accuracy of different turbulence modeling techniques. The results of steady RANS and Large Eddy Simulation (LES) were compared with PIV data, which was obtained within the same project. The far wake structure behind the wheel was dominated by two strong counter-rotating vortices. The locations of the vortex cores, extracted from the LES and PIV data as well as computed using different RANS models, showed that the LES predictions are closest to the …


A Shooting Algorithm For Complex Immunodominance Control Problems, Xiaopeng Zhao, R Yang, M Zhang Jan 2009

A Shooting Algorithm For Complex Immunodominance Control Problems, Xiaopeng Zhao, R Yang, M Zhang

Faculty Publications and Other Works -- Mechanical, Aerospace and Biomedical Engineering

Although T cells are able to recognize a wide variety of target peptides, they are often strongly focused on a few of the peptides and leave the rest of them unattended. This phenomenon of strongly biased immune response is known as immunodominance. Mathematically, an immunodominance problem can be formulated using optimal control principles as a two-point boundary-value problem. The solution of this problem is challenging especially when the control variables are bounded. In this work, we develop a numerical algorithm based on the shooting technique for bounded optimal control problems. The algorithm is applied to a group of immunodominance problems. …


Rembrant: Research On The Effects Of Microgravity On The Brazil Nut Problem, Getaway Special Team 2009 Jan 2009

Rembrant: Research On The Effects Of Microgravity On The Brazil Nut Problem, Getaway Special Team 2009

Reports and Proposals

No abstract provided.


Funboe Factsheet, Getaway Special Team 2009 Jan 2009

Funboe Factsheet, Getaway Special Team 2009

Reports and Proposals

No abstract provided.


Ipas: International Paper Airplanes In Space, Getaway Special Team 2009 Jan 2009

Ipas: International Paper Airplanes In Space, Getaway Special Team 2009

Reports and Proposals

No abstract provided.


Sides: Space Italian Dressing Experimental Setup, Getaway Special Team 2009 Jan 2009

Sides: Space Italian Dressing Experimental Setup, Getaway Special Team 2009

Reports and Proposals

No abstract provided.


Synthesis And Characterization Of Birnessite And Cryptomelane Nanostructures In Presence Of Hoffmeister Anions, Marcos A. Cheney, Robin Jose, Arghya Banerjee, Pradip K. Bhowmik, Shizhi Qian, Joseph M. Okoh Jan 2009

Synthesis And Characterization Of Birnessite And Cryptomelane Nanostructures In Presence Of Hoffmeister Anions, Marcos A. Cheney, Robin Jose, Arghya Banerjee, Pradip K. Bhowmik, Shizhi Qian, Joseph M. Okoh

Mechanical & Aerospace Engineering Faculty Publications

The effect of Hoffmeister anions Cl(-), SO(4) (2-), and ClO(4) (-) on the structure and morphology of birnessite and cryptomelane-type manganese dioxide nanostructures, produced by the reduction reaction of KMnO(4) and MnSO(4) in aqueous acidic media, was studied. The syntheses were based on the decomposition of aqueous KMnO(4) in presence of HCl for birnessite-type and acidified MnSO4 for cryptomelane-type manganese dioxide under soft hydrothermal conditions. They were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM) techniques. XRD patterns show the formation of birnessite for the first synthesis and a mixture of cryptomelane and …


Gathering Leadership Momentum Across Great Distances: Creating An Online Community Of Practice, Erin Dini-Davis, Danielle Theiss-White Jan 2009

Gathering Leadership Momentum Across Great Distances: Creating An Online Community Of Practice, Erin Dini-Davis, Danielle Theiss-White

Library Faculty & Staff Publications

At the 2007 Mountain Plains Library Association Leadership (MPLA) Institute, held in New Mexico, USA, eight academic librarians formed an online multi-state, multigenerational community of practice. MPLA is a twelve-state library association within the United States. Using Google Groups™, the members formed an online environment called the MPLA Community of Practice for continuing development of the leadership skills presented at the Institute. These early-career librarians represent diverse educational backgrounds and work in libraries serving varied populations with differing disciplinary emphases. The group meets monthly with each member preparing and facilitating online discussions, complete with personal assessments, topical readings, and questions. …


Procedure To Validate Direct Numerical Simulations Of Wall-Bounded Turbulence Including Finite-Rate Reactions, Lian Duan, M. Pino Martín Jan 2009

Procedure To Validate Direct Numerical Simulations Of Wall-Bounded Turbulence Including Finite-Rate Reactions, Lian Duan, M. Pino Martín

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper first discusses the constitutive relations and surface catalytic model for direct numerical simulation of wall-bounded turbulence including finite-rate chemistry and gas-surface interaction and then provides a systematic procedure to test the validity of the simulations by dividing the whole problem into different components and testing each component separately. Namely, comparisons against similarity solutions and other established hypersonic boundary-layer solutions are used to test the validity of laminar mean flow with and without gas-phase chemical reactions; comparisons against the analytic solution for the one-dimensional diffusion equation are used to test the validity of the surface catalysis boundary condition; and …