Events for the 3rd week of February
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AME Seminar
Wed, Feb 17, 2021 @ 03:30 PM - 04:30 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
Speaker: Ian Tobasco, Univ. Illinois Chicago
Talk Title: Simple Rules for the Wrinkle Patterns of Confined Elastic Shells
Abstract: Dried fruits wrinkle for the same reason that leaves and flowers do -” mechanical instabilities arising from a mismatch in lengths. Can such geometric incompatibilities be used to design and control wrinkle patterns at will? This talk will discuss the possibility of designing wrinkle patterns in the large using a recently derived model for the wrinkles of confined elastic shells. After recalling the basic mechanics and introducing our model, we show how it can be solved by hand in many cases to predict the wrinkled topography. Solving this model produces a few geometric rules, which explain the layout of the wrinkle peaks and troughs across examples. These simple rules reproduce the patterns seen in numerous experiments and simulations, even ones that exhibit a surprising coexistence between orderly wrinkles and a more disordered response. Knowing such rules for wrinkles opens the way towards designer wrinkle patterns, with potential applications from flexible electronics to synthetic skins.
Biography: Ian Tobasco is an Assistant Professor at the University of Illinois at Chicago Department of Mathematics, Statistics, and Computer Science. He holds a Ph.D. in Mathematics from the Courant Institute of Mathematical Sciences at New York University, and a B.S.E. in Aerospace Engineering from the University of Michigan.
His research on the calculus of variations and partial differential equations concerns problems that sit at the interface of mathematics, physics, and engineering, where advances in pure mathematical analysis can lead to scientific breakthroughs in the lab and vice versa. His recent work involves the use of energy minimization to explain and classify the zoo of wrinkling, crumpling, and folding patterns exhibited by thin elastic sheets. Other interests include the design of optimal transport mechanisms in fluid dynamics and their comparison with naturally occurring turbulent transport, as well as the variational analysis of spin glasses.
Host: AME Department
More Info: https://usc.zoom.us/j/97445099108
Webcast: https://usc.zoom.us/j/97445099108Location: Online event
WebCast Link: https://usc.zoom.us/j/97445099108
Audiences: Everyone Is Invited
Contact: Tessa Yao
Event Link: https://usc.zoom.us/j/97445099108
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AME PhD Student Seminar
Fri, Feb 19, 2021 @ 03:00 PM - 04:00 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
Speaker: Raye Xie, USC AME PhD Student
Talk Title: Development and Validation of a Body-Force Propulsor
Abstract: This talk introduces a body-force propulsor model that replaces the engine blades with a source volume in CFD to produce the equivalent flow turning, work input, and losses. The motivation for developing this model is to capture the effects of inlet flow non-uniformity on propulsor performance, while using a local formulation appropriate for full-aircraft CFD at a computational cost compatible with design studies. The model is able to capture non-axisymmetric effects and only requires specification of the blade camber and thickness distributions. An inviscid formulation for the body-force was previously found to be capable of predicting the inviscid distortion transfer effects, but losses and blade metal blockage effects were not accounted for. An improved formulation with a blockage component is proposed here and is shown to properly predict the propulsor work. Loss terms are included to model 2D profile losses and secondary flow losses. The proposed model is implemented in the flow solver ADflow and validated against NASA rotor 67 experimental data.
Biography: Tianbo (Raye) is a PhD student supervised by Dr. Alejandra Uranga. His research focuses on engine/propulsor modeling in high-fidelity simulations and full-aircraft simulations. Raye has a B.S. from Rensselaer Polytechnic Institute, and a M.S. from USC.
Host: AME Department
More Info: https://usc.zoom.us/j/96549200347?pwd=Uytmd05JbE5qQnRzeEpDSVBXL2ZFZz09
Audiences: Everyone Is Invited
Contact: Christine Franks
Event Link: https://usc.zoom.us/j/96549200347?pwd=Uytmd05JbE5qQnRzeEpDSVBXL2ZFZz09