Conferences, Lectures, & Seminars
Events for September
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Aerospace & Mechanical Engineering Department
Wed, Sep 05, 2012 @ 03:30 PM - 04:30 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
Speaker: Konstantin Matveev , Associate Professor, School of Mechanical and Materials Engineering, Washington State University Pul,lman, Washington
Talk Title: Aero-Hydrodynamics and Dynamics of Air-Assisted Marine Vehicles
Abstract: Drag reduction of large cargo vessels can be achieved by lubricating submerged hull surfaces with air layers. Higher speeds of small fast boats can be attained by utilizing aerodynamic lift. Air-cavity ships, ultra-fast planing multi-hulls (racing boats), wing-in-ground-effect vehicles, and power-augmented-ram platforms are examples of marine craft with air assistance. The main technical problem in the development and application of these concepts for marine transportation is to ensure high performance and motion stability in a broad range of operational conditions, including motions in water waves. We will discuss an experimental study on air-cavity flows under a simplified hull model, associated modeling efforts based on hydrodynamic singularities and viscous solvers, and an example of industrial development of a large air-cavity cargo vessel. We will also illustrate applications of the extreme-ground-effect theory for aerodynamics of fast air-supported boats. Simulation results will be presented for hydroplane dynamics, including responses to initial perturbations, reactions to wind gusts, and motions in head and following waves. Video clips of our self-propelled radio-controlled models of power-augmented-ram vehicles will be demonstrated.
Biography: Konstantin Matveev obtained a Master degree in Applied Physics from Moscow Institute of Physics and Technology in 1996 and a Ph.D. degree in Mechanical Engineering from California Institute of Technology in 2003. His Ph.D. thesis was on thermoacoustic and combustion instabilities. As a postdoc at Los Alamos National Laboratory, Dr. Matveev investigated nonlinear thermoacoustic phenomena in advanced energy systems. As a senior hydrodynamicist at Art Anderson Associates and a consultant to several European R&D organizations, he was involved in the development of high-performance marine concepts, including air-lubricated hulls, hydrofoils, multi-hull ships, and wing-in-ground craft. He recently co-authored a technical book on Small-Waterplane-Area Ships. At the present time, Dr. Matveev is an Associate Professor in the School of Mechanical and Materials Engineering at Washington State University. His current research is focused on advanced marine vehicles and thermoacoustics.
Host: Prof. Eva Kanso
More Info: http://ae-www.usc.edu/seminars/9-5-12-matveev.shtml
Location: Seaver Science Library (SSL) - Room 150
Audiences: Everyone Is Invited
Contact: April Mundy
Event Link: http://ae-www.usc.edu/seminars/9-5-12-matveev.shtml
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Aerospace & Mechanical Engineering Dept. Seminars
Wed, Sep 12, 2012 @ 03:30 PM - 04:30 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
Speaker: Tonghun Lee , Associate Professor Department of Mechanical Engineering Michigan State University East Lansing, Michigan
Talk Title: Application of Laser and Optical Diagnostics for Study of Next Generation Propulsion Systems and Integration of Alternative Bio-derived Fuels
Abstract: Development of advanced propulsion systems of the future, such as hypersonic ramjets and pulsed detonation engines will require a deeper understanding of the reactive flow dynamics and chemistry in the relevant turbulent regime as well as development of new energetically enhanced combustion technologies. Additionally, these new engines will require seamless operation across a wide range of new and alternative bio-derived fuels as well as conventional hydrocarbon counterparts. This presentation will discuss recent progress in applying laser and optical diagnostics to study high Reynolds number reactive flows, plasma enhanced flames, as well as ignition and oxidation of alternative bio-derived jet fuels for potential integration in next generation propulsion systems. The following three topics will be discussed.
First is an effort to develop a continuous high-speed (>10 kHz) laser imaging system which integrates PLIF, PIV, and Rayleigh Scattering Thermometry (RST) for detection of temperature fields as well as velocity and chemical species. The proposed work will increased the number of detectable species in reactive flows by extending the wavelength range further into the UV with enhanced beam stability through non-linear optical engineering. Second is a novel concept of energetically enhancing the combustion by using a non-equilibrium plasma discharge. Highly efficient flame stabilization is achieved using a non-equilibrium plasma discharge by coupling the plasma energy directly into the reaction zone of the flame. The electrons and ions generated by the plasma introduce new chemical pathways which enhance and accelerate the combustion chemistry. The third topic of discussion is investigating the ignition and oxidation characteristics of bio-derived jet fuels. A rapid compression machine is modified for ignition testing of heavy fuel blends using a 'direct test chamber' fuel preparation method as well as optical access for laser and optical diagnostics.
Biography: Tonghun Lee is an associate professor in the Department of Mechanical Engineering at Michigan State University. Prior to working at Michigan State University, he was a graduate student at Stanford University where he obtained his M.S. (2002) and Ph.D. (2006) degrees in the 'High Temperature Gas Dynamics Laboratory.' His research is focused on utilizing laser and optical diagnostics to investigate new combustion concepts in advanced propulsion and energy conversion systems, with particular emphasis on supersonic air-breathing engines and high-pressure combustion research. He has been recognized with numerous awards including the AFOSR Young Investigator Award, the ONR Young Investigator Award, and the Presidential Early Career Award for Scientists and Engineers (PECASE).
Host: Professor Fokion Egolfopoulos
More Info: http://ae-www.usc.edu/seminars/9-12-12-lee.shtml
Location: Seaver Science Library (SSL) - Room 150
Audiences: Everyone Is Invited
Contact: April Mundy
Event Link: http://ae-www.usc.edu/seminars/9-12-12-lee.shtml
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Aerospace & Mechanical Engineering Dept. Seminar
Wed, Sep 19, 2012 @ 03:30 PM - 04:30 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
Speaker: Lorenzo Valdevit , Assistant Professor, Mechanical and Aerospace Engineering Department, University of California, Irvine
Talk Title: Hierarchical Architected Materials as a Platform for Novel Multifunctional Systems
Abstract:
Periodic cellular materials are desirable for applications requiring high specific stiffness and strength. If the architecture is open-celled, a number of multifunctional attributes can be added, with potential for multi-objective optimization. Although conventional industrial technologies limit the achievable unit cell complexity, recent progress in advanced manufacturing is enabling fabrication of hierarchical cellular materials of nearly any topology with wide dimensional bandwidth (i.e., the ratio of the dimension of the largest to the smallest feature in the architecture).
Hierarchical unit cell designs with wide dimensional bandwidth are showing particular promise, often revealing unique mechanical behavior. Furthermore, if the smallest feature in the architecture is at the sub-micron scale, unique size effects in plasticity can further improve the mechanical response.
In this presentation, I will discuss novel ultra-light micro-architected nickel hollow-truss lattices with unprecedented combinations of density, stiffness, strength and damping characteristics. Results of extensive experimental investigations (both at the nano and macro-scale) will be presented, alongside numerical models and optimal design tools. Some preliminary work on ceramic and hybrid architected materials manufactured by 3D printing will also be discussed. Collectively, all these investigations indicate that a strong synergism among advanced manufacturing, materials science, multi-scale experimental and computational mechanics and sophisticated optimization tools is required to reach the full potential of hierarchical architected materials.
Biography: Lorenzo Valdevit received his MS degree (Laurea) in Materials Engineering from the University of Trieste, Italy (in 2000) and his PhD degree in Mechanical and Aerospace Engineering from Princeton University (in 2005). He worked as an intern at the IBM T.J. Watson Research Center and as a post-doctoral scholar at the University of California, Santa Barbara. He is presently an Assistant Professor in the Mechanical and Aerospace Engineering Department at the University of California, Irvine (with a joint appointment in Chemical Engineering and Materials Science). He is a member of Pi Tau Sigma and Tau Beta Pi and is the recipient of the 2007 Faculty Award from IBM Corporation. His primary research goal is the optimal design, fabrication and experimental characterization of micro-architected materials with superior combination of properties. His group has recently developed novel micro-mechanical test frames and numerical algorithms to help achieve this overarching goal.
Host: Prof. Andrea Hodge
More Info: http://ame-www.usc.edu/seminars/9-19-12-valdevit.shtml
Location: Seaver Science Library (SSL) - Room 150
Audiences: Everyone Is Invited
Contact: April Mundy
Event Link: http://ame-www.usc.edu/seminars/9-19-12-valdevit.shtml
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Aerospace and Mechanical Engineering Department Seminar
Wed, Sep 26, 2012 @ 03:30 PM - 04:30 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
Speaker: Katharine M. Flores , Professor and Associate Chair,Department of Mechanical Engineering and Materials Science
Talk Title: From the Atoms Up: Design and Deformation of Metallic Glasses and their Composites
Abstract:
Metallic glasses, metallic alloys with disordered atomic structures, have matured from laboratory curiosities to engineering alloys of interest for their remarkable mechanical properties and processability. The unique atomic structure of these alloys presents a number of challenges for describing and controlling their behavior, as well as intriguing manufacturing opportunities. Lacking long-range structural order and the attendant microstructure, metallic glasses do not require multiscale modeling to capture many essential characteristics of their behavior and thus are an ideal model system for the development of a computationally driven "atoms-up" approach to alloy design. We use molecular dynamics to determine the liquid fragility for a series of Cu-Zr alloys and discuss this measure of the dynamics of the system in light of observations of the short-range atomic ordering of the alloy. Based solely on these parameters calculated from molecular dynamics, we suggest an a priori predictor for glass forming ability.
While monolithic metallic glasses exhibit near theoretical strengths and large elastic deflections, their lack of extensive tensile ductility limits their structural applications. Microstructural control has long been the materials scientist's chief tool for improving material properties. By creating metallic glass-crystalline composites, we introduce microstructural features and gain control over the initiation and distribution of plastic deformation. Building upon our computationally-driven approach to the design of the glassy phase, we next seek to design metallic glass composites with desirable properties. This requires adequate understanding of the role of microstructure on the plastic deformation mechanisms in order to calibrate and validate the model. One family of composites utilizes ductile crystalline dendrites which precipitate from the melt prior to vitrification of the matrix. Our work to quantitatively characterize this microstructure and its role in the resulting mechanical behavior will be discussed. Full field strain mapping measured from in situ digital image correlation reveals that at relatively low strains, the glassy matrix acts as an isotropic "buffer layer" between crystals of different orientations, permitting the crystals to deform unimpeded along their preferred slip system.
Biography: Katharine Flores is Professor and Associate Chair of Mechanical Engineering and Materials Science at Washington University, as well as the Associate Director for the new interdisciplinary Institute of Materials Science and Engineering. After receiving her B.S. in Mechanical Engineering from Washington University in 1995, she attended Stanford University where she received her Ph.D. in Materials Science and Engineering in 2000. She joined the Materials Science and Engineering Department at the Ohio State University as an assistant professor in 2002, and moved to her current position at Washington University in July, 2012. Her primary research interest is the mechanical behavior of structural materials, with particular emphasis on understanding structure-processing-property relationships in bulk metallic glasses and their composites, an area in which she has worked for almost 15 years. She leads research projects on topics ranging from investigations of the structural origins of plastic deformation in metallic glasses to the design of new glasses with desirable properties and the development of new manufacturing techniques suited to the unique processing capabilities of these alloys, in an effort to accelerate their incorporation in mainstream and high performance applications. In 2005, she received two prestigious early-career awards for her work in this area, a National Science Foundation CAREER Award and an Office of Naval Research Young Investigator Award. In addition to her research, Dr. Flores is actively involved in outreach and was the Director of Education and Outreach for the Center for Emergent Materials, the NSF Materials Research Science and Engineering Center at OSU, from 2008-2012. In 2011, she was a co-recipient of an Ohio Faculty Innovator Award for her efforts to improve undergraduate instruction in materials science and engineering.
Host: Profs. Hodge/Eliasson
More Info: http://ame-www.usc.edu/seminars/9-26-12-flores.shtml
Location: Seaver Science Library (SSL) - Room 150
Audiences: Everyone Is Invited
Contact: April Mundy
Event Link: http://ame-www.usc.edu/seminars/9-26-12-flores.shtml