Conferences, Lectures, & Seminars
Events for February
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AME Department Seminar
Wed, Feb 02, 2011 @ 03:30 PM - 04:30 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
Speaker: B. Villac , Professor, University of California at Irvine
Talk Title: Humans Beyond Low Earth Orbits: Challenges and Opportunities in Astrodynamics
Abstract: The NASA plan for sending humans beyond low-Earth orbits in a sustainable manner poses many challenges (at all levels: technical, political,...), as well as a plethora of opportunities. This talk explores a few of the technical challenges and opportunities in the realm of spaceflight dynamics.
Firstly, sustained exploration implies a need for space-based infrastructure, notably for navigation and communication systems. This leads us to a discussion on constellation optimization in multi-body environments, and the associated variational problems. We show that the use of dynamical system theory and the analysis of periodic orbit families allows us to reduce this problem to a one-dimensional optimization over a graph. These results are applied to the concept of autonomous navigation constellation. The notion of family --i.e., continuous set of orbit-- is then extended to transfer problems, demonstrating some limitations of classic design methodologies and possible techniques to go around these.
Secondly, humans in space also implies safety issues. This is notably amplified with the current vision of sending humans to asteroids, where the dynamics present short time scales and is generally poorly characterized before encounter. Here the questions addressed are the techniques to ensure mission recovery --or at least avoiding critical events such as impacts or uncontrolled escape when orbiting a small body-- in the face of potential engine failure. The analysis of the resulting optimal control problems and orbital stability issues leads to new transfer and mission concepts and the challenging problem of orbital motion characterization under large parameter uncertainties.
Finally, a few astronauts in space means a large team of qualified engineers on the ground, planning, designing, preparing, operating, supporting the missions ans the astronauts. All this, starts with education and the formation of good engineers. The last part of the talk will briefly discuss the cubesat project pursued at UCI in order to answer this need.
Biography: Prof. Villac is currently assistant professor at the University of California, Irvine (UCI). Prior to joining UCI in 2006, Prof. Villac worked at the Jet Propulsion Laboratory and the California Institute of Technology, developing novel low-thrust trajectory analysis and design methods for the Jupiter Icy Moon Orbiter mission. He received his Ph.D in aerospace engineering in 2003 from the University of Michigan, Ann Arbor. His research is focused on astrodynamics, exploring the applications of modern dynamical system theory to the analysis and development of new space mission concepts. He is also advising the UCISAT project which is currently preparing to launch its first cubesat.
Host: Prof. F. Udwadia
More Info: http://ame-www.usc.edu/seminars/2-2-11-villac.shtmlLocation: Seaver Science Library (SSL) - 150
Audiences: Everyone Is Invited
Contact: April Mundy
Event Link: http://ame-www.usc.edu/seminars/2-2-11-villac.shtml
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AME Department Seminar
Wed, Feb 09, 2011 @ 03:30 PM - 04:30 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
Speaker: Louis Komzsik , Chief Numerical Analyst, Office of Architecture and Technology, Siemens PLM Software
Talk Title: An Introduction to Industrial Rotor Dynamics
Abstract: The rotational phenomenon is instrumental in our everyday lives. The effects of the phenomenon range from the well known centrifugal force, through the Coriolis forces and to the Euler force. The modeling and computation of such forces forms the basis of rotor dynamics. Rotor dynamics of elastic structures is a very important topic of the energy (turbines and windmills) and transportation (helicopter and airplane propellers) industry. The talk will briefly review the physical fundamentals of rotating phenomenon and its computational formulation with finite elements. It will also present a demonstration example and an industrial case study from NASTRAN, the world leader in commercial finite element analysis. It is aimed at undergraduate and graduate engineering or computational science students, but well suited for interested faculty as well.
Biography: Dr. Louis Komzsik, Chief Numerical Analyst of Siemens Industry Division, PLMS. He is a graduate of the Technical University of Budapest in Hungary and worked for almost four decades in the industry, the last three in the United States. His work focuses on developing computational techniques for industrial applications in commercial finite element analysis. Dr. Komzsik is the author of several books; one on them on Lanczos method published by SIAM has also been published in Japanese, Hungarian and Chinese. His book about Computational Techniques of Finite Element Analysis is in its second edition and used by engineers worldwide. His Approximation Techniques for Engineers and Applied Calculus of Variations for Engineers books are used at several universities in the US and in Europe.
Host: Prof. G. Shiflett
More Info: http://ame-www.usc.edu/seminars/index.shtml#upcomingLocation: Seaver Science Library (SSL) - 150
Audiences: Everyone Is Invited
Contact: April Mundy
Event Link: http://ame-www.usc.edu/seminars/index.shtml#upcoming
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AME Department Seminar
Wed, Feb 16, 2011 @ 03:30 PM - 04:30 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
Speaker: Robert Dudley , Professor, University of California at Berkeley
Talk Title: From Gliding Ants to Andean Hummingbirds and Giant Dragonflies: The Origins and Evolution of Animal Flight
Abstract: Unsteady aerodynamic mechanisms underpinning animal flight have recently been intensively studied, but less well understood are those evolutionary pathways leading to the acquisition and subsequent elaboration of flapping flight. Recently discovered behaviors in Neotropical canopy ants demonstrate directed aerial descent in the complete absence of wings; controlled aerial behavior appears to have preceded the origin of wings in insects and other flying animals. Variation in atmospheric composition during the late Paleozoic may have influenced the initial evolution and subsequent diversification of insects, as well as the widespread phenomenon of arthropod gigantism, including but not limited to dragonflies with a 70 centimeter wingspan. For fully flighted forms, judicious use of helium to create physically variable gas mixtures permits decoupling of physiological from aerodynamic constraints on hovering performance. Such constraints are revealed in natural contexts through the study of hummingbird and bumblebee flight capacity across steep altitudinal transects.
Host: Prof. G. Spedding
More Info: http://ame-www.usc.edu/seminars/2-16-11-dudley.shtmlLocation: Seaver Science Library (SSL) - 150
Audiences: Everyone Is Invited
Contact: April Mundy
Event Link: http://ame-www.usc.edu/seminars/2-16-11-dudley.shtml
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AME Department Seminar
Wed, Feb 23, 2011 @ 03:30 PM - 04:30 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
Speaker: Stephen B. Pope, Professor, Sibley School of Mechanical & Aerospace Engineering, Cornell University
Talk Title: Advances in Computer Simulations of Turbulent Combustion
Abstract: Combustion will remain a key technology for several decades in power generation, transportation and many other applications. Advances are continually sought in terms of efficiency gains, pollution reduction, and alternative technologies facilitating carbon capture. As in other areas of engineering, computer simulations are central to the design and development of combustion technologies. Great strides are being made both in the computation fluid dynamics (CFD) of turbulent reactive flows and in the development of more accurate and comprehensive chemical mechanisms, which may involve thousands of species. However, the combination of advanced approaches to turbulent flows and large chemical mechanisms poses a formidable computational challenge. The approach to the simulation of turbulent combustion described in this talk consists of the following three components: large-eddy simulation (LES) to treat the flow and turbulence; a probability density function (PDF) method to treat the turbulence-chemistry interactions; and, dimension-reduction and tabulation for the computationally-efficient implementation of combustion chemistry. Recent advances and examples of simulations are presented.
Host: Dr. P. Roney
More Info: http://ame-www.usc.edu/seminars/2-23-11-pope.shtmlLocation: Seaver Science Library (SSL) - 150
Audiences: Everyone Is Invited
Contact: April Mundy
Event Link: http://ame-www.usc.edu/seminars/2-23-11-pope.shtml