Students

MAE Colloquium - Winter 2017

The Aerospace Engineering Colloquium (AE 598) is a required course that satisfies the professional development component of the Master of Aerospace Engineering (MAE). MAE students are required to complete nine (9) credits of colloquium participation to satisfy the degree requirements. However, all members of the UW community are welcome to attend and participate.

Topics may include current research and advances in aerospace technology as well as other themes relevant to the professional development of aerospace engineers. To earn credit for this course, students must complete a required set of writing assignments.

Download Course Description, Grading, and Assignment Details

Winter 2017

Mondays, 4:00 - 5:00 pm
Electrical Engineering Building Room 105

Faculty Coordinator: Tony Waas

Current Week's Information

January 2

No Speaker This Week - University Holiday

January 9

No Speaker This Week - SciTech Meeting

January 16

No Speaker This Week - University Holiday

January 23

Avian Inspired Multifunctional Morphing Air Vehicles

Morphing or shape changing wings on aircraft is as old as the Wright Brothers who used wing warping actuated by cables for flight control. Because of the need for rigid wings to avoid flutter this type of flight control gave way to discrete control surfaces (flaps, rudder, aileron, elevator). In the late 1990’s interest returned to using shape changing wing configurations to replace discrete control surfaces. Most solutions where based on using conventional actuation schemes and were not much influenced by avian motions. Here we trace some of the more recent morphing efforts and discuss a program to integrate smart, multifunctional materials and structures into avian inspired morphing aircraft for flight control of unmanned air vehicles.

Daniel J. Inman received his Ph.D. from Michigan State University in Mechanical Engineering in 1980 and is Chair of the Department of Aerospace Engineering at the University of Michigan, as well as the C. L. “Kelly” Johnson Collegiate Professor. Since 1980, he has published eight books (on vibration, energy harvesting, control, statics, and dynamics), eight software manuals, 20 book chapters, over 330 journal papers and 600 proceedings papers, given 62 keynote or plenary lectures, graduated 62 Ph.D. students and supervised more than 75 MS degrees. He works in the area of applying smart structures to solve aerospace engineering problems including energy harvesting, structural health monitoring, vibration suppression and morphing. He is a Fellow of ASME, AIAA, SEM, IIAV and AAM.

Suggested Readings:

Morphing Aerospace Vehicles and Structures, Ed. Valasek, J., Wiley, 2012.

January 30

Multi-functional Microvascular Composites: Computational Analysis and Design

Inspired from many living organisms, microvascular composites form a new class of fiber-reinforced polymeric matrix composites that contain a circulatory system made of an embedded network of microchannels. Based on the choice of the fluid circulating in the microvascular network, a wide range of multi-functionalities are being considered for these materials, including autonomic healing of internal damage, switching embedded antennas, and active cooling for high temperature applications. A recent development in the manufacturing of this class of composites, based on specially treated sacrificial fibers that are woven in the original fabric, undergo the composite cure cycle before undergoing a vaporization process, has led to the creation of microvascular networks that are integrated directly into the composite microstructure. This technology is being considered for a variety of active cooling applications, including skin materials for hypersonic aircrafts, actively cooling of car batteries and radiative cooling of nanosatellites.

This new manufacturing process provides a lot of flexibility in the configuration of the embedded network. To assist with the material design process, a novel numerical tool based on an interface-based generalized finite element method (IGFEM) has been developed to model accurately and efficiently the impact of the coolant flowing through the microchannels on the thermal field in the composite. A gradient-based shape optimization scheme is then used together with the IGFEM solver to optimize the configuration of the embedded microchannel network based on a variety of objective functions and constraints. Various 2D and 3D configurations of the microchannels are investigated and compared, based on their thermal and flow efficiency and on their impact on the structural integrity of the composite. We also optimize the microchannel network for redundancy.

Originally from Belgium, Philippe Geubelle got his M.S. and Ph.D. in Aeronautics at Caltech in 1989 and 1993, respectively. After a year as Postdoctoral Research Associate at Harvard, he joined the University of Illinois at Urbana-Champaign in January 1995, where he is currently Bliss Professor and Head in the Department of Aerospace Engineering, with joint appointments in Mechanical Science and Engineering, at the National Center for Supercomputing Applications and at the Beckman Institute of Advanced Science and Technology. He is also serving as Director of the Illinois Space Grant Consortium and Board President of the National Space Grant Foundation. His research interests pertain to the theoretical and numerical treatment of complex problems in solid mechanics and materials, and, in particular, the multidisciplinary computational analysis and design of multifunctional, biomimetic materials, fracture mechanics, multiscale modeling of heterogeneous materials, composite manufacturing, and thin films for MEMS and microelectronics applications. Other research activities include computational aeroelasticity, structural/acoustic coupling and parallel programming.

Suggested Readings:

To be announced.

February 6

Miniature-Scale Plasma Confinement for Space Electric Propulsion

Miniature spacecraft have become an important part of the future of space science and exploration. Many of these missions require high-efficiency miniature electric propulsion to provide in-space maneuvers and station keeping. This talk will first discuss some of the miniature electric propulsion technologies developed at UCLA’s Plasma and Space Propulsion Laboratory, including the world’s first miniature noble gas ion thruster (MiXI: Miniature Xenon Ion) and the world’s first “immortal” miniature Hall thruster that incorporates magnetic shielding (MaSMi: Magnetically Shielded Miniature). Missions for these thrusters include formation flying and micro- and nano-satellite exploration missions to the Moon and nearby asteroids.

With regards to MiXI, we have recently developed a new approach to miniature cusped discharge design that overcomes traditional scaling limitations. Our approach results in performance improvements of nearly 20%, thus rivaling the performance of full-scale thrusters. This accomplishment was the culmination of a multi-year effort combining experiments, simulations, and theoretical analyses. Through this effort, we were able to show that plasma cusp confinement at the micro-scale does not follow conventional theory for hybrid loss width (i.e., traditionally assumed to be the geometric mean for ion and electron gyro radii, rhybrid∝rire ). In contrast, our analyses show dramatically different loss behavior for miniature-scale plasma discharges, which exhibit complex ridge shapes for the collection area. This behavior can be explained by careful consideration of the upstream magnetic field and the related electron drift that results in both electron and plasma loss.

The talk will also cover our first-ever efforts related towards: (1) canonical experiments of ion-neutral interactions in thruster plumes, (2) measurements and simulations of the secondary electron interaction at plasma-facing surfaces, (3) and plasma-material interactions for featured surfaces. In our lab, we have developed the Plasma-Material Interactions (“Pi”) Facility, which uses an axially magnetized cylindrical plasma discharge to deliver a wide range of plasma conditions to a material target. The Pi Facility has made significant discoveries through its use of a wide range of non-intrusive and in situ diagnostics, including a long distance optical microscope for examining in-situ plasma-surface interactions. Time permitting, at the end of the talk, Prof. Wirz will give a brief overview of his Energy Innovation Laboratory’s efforts in large-scale energy storage and advanced wind turbine blade design.

Prof. Richard Wirz is an Associate Professor in UCLA’s Department of Mechanical and Aerospace Engineering, and holds a joint appointment at the NASA/JPL Electric Propulsion Group. He received his Ph.D. and M.S. degrees from Caltech and two engineering B.S. degrees from Virginia Tech. He is the Director of the UCLA Plasma and Space Propulsion Laboratory and the UCLA Energy Innovation Laboratory (www.WirzResearchGroup.com). His plasma lab investigates several topics related to electric propulsion and micropropulsion, including: low-temperature plasma discharges, plasma-material interactions, mission analysis, and spacecraft plasma interactions. His energy lab investigates large-scale energy challenges in both wind and solar.

Suggested Readings:
  • Patino M.I., Raitses Y., Wirz R.E., “Secondary electron emission from plasma-generated nanostructured tungsten fuzz,” Applied Physics Letters, 109, 201602 (2016); doi: 10.1063/1.4967830
  • Dankongkakul B., Araki S. J., Wirz R.E., “Magnetic field structure influence on primary electron cusp losses for micro-scale discharges,” Physics of Plasmas (featured on cover), 21, 043506 (2014); doi: 10.1063/1.4871724
  • Conversano R., Goebel D.M., Hofer R.R., Matlock T.S., Wirz R.E., “Development and Initial Testing of a Magnetically Shielded Miniature Hall Thruster”, Plasma Science, IEEE Transactions on, PP, 99 (2014) doi: 10.1109/TPS.2014.2321107
  • Matlock T.S., Goebel D.M., Conversano R., Wirz R.E., “A dc plasma source for plasma–material interaction experiments,” Plasma Sources Sci. Technol. 23 (2014) 025014 (11pp)
  • www.WirzResearchGroup.com 

February 13

Landing SpaceX's Reusable Rockets

SpaceX's reusable rocket program aims to reduce the cost of space travel by making rockets that can land, refuel and refly, instead of being thrown away after every flight. Precise landing of a rocket is a unique problem, which has been likened to balancing a rubber broomstick on your hand in a windstorm. Rockets do not have wings (unlike airplanes) and they cannot rely on a high ballistic coefficient to fly in a straight line (unlike missiles). In the past year, SpaceX has successfully landed five rockets, two of which were on dry land at Cape Canaveral, and three of which were on a floating platform in the Atlantic. This talk will discuss the challenges involved, how these challenges were overcome, and next steps towards rapid reusability.

Lars Blackmore is responsible for Entry, Descent and Landing of SpaceX's Falcon 9 Reusable (F9R) rocket. His team developed the precision landing technology required to bring F9R back to the launch site. Previously, Lars was with the NASA Jet Propulsion Laboratory, where he was co-inventor of the G-FOLD system for precision landing on Mars, and was a member of the control team for the SMAP climate change observatory. Lars was recently named one of MIT Tech Review's "35 under 35" innovators. Lars has a PhD in Guidance, Navigation and Control from the MIT Department of Aeronautics and Astronautics, where he was a Kennedy Scholar, and recipient of the AIAA Guidance Navigation and Control Graduate Student Award.

Suggested Readings:

To be announced

February 20

No Speaker This Week - University Holiday

February 27

Oh My Aching Back! — Protective Aircraft Seat Design Using Magnetorheological Systems

The ability to dissipate energy in vehicle systems, especially with the goal of protecting occupants from potentially injurious vibration, repetitive shock, crash and blast loads, is becoming a critical issue as the cumulative impact of these load spectra on chronic health and acute injury are becoming better understood. Energy is dissipated utilizing a stroking element, such as a hydraulic damper or energy absorber. However, it is difficult to anticipate precisely what range occupant mass an isolation system might be expected to protect, or what vibration and shock spectra the system might encounter. Therefore, adaptation of stroking load is required to enable a system to have sufficient adjustability or control capability to effectively dissipate energy across a wide range of anticipated and even unanticipated disturbances. The goals of this research are threefold: (1) to develop field dependent or controllable energy absorbing materials, especially magnetorheological (MR) fluids, (2) to develop magneto-rheological energy absorbers (MREAs) to enable adaptation of stroking load in order to minimize lumbar loads in the human spine and thereby minimizing the potential for injury, and (3) to protect occupants or payloads from a wide range of vibration and shock spectra, as well as to accommodate a population of occupants of different mass. Applications to crew seating and landing gear in rotorcraft will be discussed. The transition of these protective seat technologies to ground vehicles and high speed boats will also be discussed.

Dr. Wereley‘s research interests are in dynamics and control of smart structures applied to helicopters and other aerospace and automotive systems, with emphasis on active and passive vibration isolation, shock mitigation (especially occupant protection systems), and actuation systems. Dr. Wereley has published over 210 journal articles, 16 book chapters, and over 275 conference articles. Dr. Wereley is an inventor on 20 patents and several patents pending. Dr. Wereley is Editor of the Journal of Intelligent Material Systems and Structures and associate editor of Smart Materials and Structures and AHS Journal. He is the recipient of several awards including AIAA National Capital Section Engineer of the Year (2009), AIAA Sustained Service Award (2011), the AHS Harry T. Jensen Award (2011), and the ASME Adaptive Structures and Materials Systems Best Paper Award in Structural Dynamics and Control (2004, 2012). Dr. Wereley is also the recipient of the ASME Adaptive Structures and Material Systems Prize (2012) and the SPIE Smart Structures and Materials Lifetime Achievement Award (2013). Dr. Wereley is a Fellow of AIAA, ASME, SPIE, and the Institute of Physics. He is also a Senior Member of IEEE and a lifetime member of AHS. Dr. Wereley has a B.Eng. (1982) from McGill University and M.S. (1987) and Ph.D. (1990) from the Massachusetts Institute of Technology.

Suggested Readings:

March 6 

Damage Tolerance of Heterogeneous Material Systems With Complex Micro-Structures

In this talk I will present my recent research on heterogeneous materials systems with complex microstructures. Notions of direct numerical simulations of complex microstructures using Trefftz, Quasi-Trefftz, and Symmetric Galerkin BEM methods will be discussed. Near-Exact and highly efficient elastic-plastic homogenizations of low-mass metallic cellular materials with architected microstructures will be presented. Damage propagation using the MLPG-Eshelby Method will be presented.

Satya Atluri, who is currently employed by Texas Tech University, has mentored nearly 700 students, postdocs, and visiting professors, in his 50 years of academic career. The details of his career may be found at: http://www.depts.ttu.edu/coe/CARES/atluri.php

Suggested Readings:

My recent papers which form the basis of my talk are all posted at: http://www.depts.ttu.edu/coe/CARES/pubs.php