Issue: Fall 2009 IssueVectors, the MMAE department magazine is an annual publication for alumni, prospective students, and industry professionals. Browse the pages to find out more about programs, faculty research, alumni, and students in the Department of Mechanical, Materials, and Aerospace Engineering at Illinois Institute of Technology.
2008 Issue (PDF)
2007 Issue (PDF)
Research Highlights: Associate Professor Herek Clack
A New Approach to Cleaning the Air
Associate Professor Herek Clack leads the Advanced Thermal and Environmental Systems Research (ATESR) Laboratory , which focuses on understanding and enhancing the mass transfer associated with pre- and post-combustion phenomena and mercury emissions.
Mercury emissions control, as required for coal-burning power plants, requires a much more complex system than those of other air pollutants, and both chemical kinetic and mechanical challenges have hindered the development of control technology in this area. Clack's post-combustion research centers on the mechanical aspect. Currently, the leading strategy for reducing mercury emissions is to inject a powdered adsorbing material into the flue gases, just before the emissions enter an electrostatic precipitator. Using electric fields to draw the particles from the flue gas, ESPs can process large volumes of gas efficiently, making them the most widely used method for capturing the ash residue from coal combustion. Addressing multiple aspects of this system, the ATESR Lab has developed a numerical model of mercury adsorption within the ESP that incorporates the charge-driven particulate motion. Another development focuses on the unwanted process of coagulation, which diminishes sorbent effectiveness by reducing the surface area available to adsorb mercury. With this in mind, recent graduate Eric Lee (MAE '09) developed a laser light extinction technique for detecting this process within the adsorbent powder as it is pumped through feed lines prior to injection. Speaking proudly of his student, Clack states, "Lee was able to experimentally verify the onset of coagulation in lab-scale tests, demonstrating in the lab this unwanted phenomenon whose presence had been suspected by industry experts, but which had never been confirmed in full-scale tests."Find out more about the ATESR Lab.
Research Highlights: Assistant Professor Matthew Peet
Solving Impossible Problems Approximately
The computational research of Assistant Professor Matthew Peet centers on the reliability of unmanned aircraft. In his work, Peet strives to significantly reduce the costly and dangerous margins of error by combining techniques such as relaxation algorithms and parallel computing.
Most complex and nonlinear control problems are classified as NP-hard, which means that the overwhelming majority of researchers consider them too hard to solve. While this view is correct if a problem is to be solved exactly, NP-hardness does not imply that a problem cannot be solved approximately. Peet has found in this distinction a way to use computation to solve complex problems in a way that is approximate, but with provable upper bounds on accuracy that decrease with accelerated computing power. In particular, he has pioneered the field of polynomial computing, which uses polynomials as variables instead of matrices. Along with collaborators at Massachusetts Institute of Technology, Stanford University, and the University of Oxford, he has created software packages such as SOSTOOLS and DelayTools, which are capable of designing controllers for systems with nonlinearity, delay, structural modes, and fluid interaction. In the process, he has also discovered some fundamental properties of dynamical systems and the way in which they interact.Find out more about Peet's research.
Research Highlights: Associate Professor Boris Pervan
Enabling High Accuracy and Integrity Navigation of Unmanned Air Vehicles
Associate Professor Boris Pervan questions whether integrity risk calculations used in GPS navigation can be approached in a more efficient manner.
Pervan and senior research associate Samer Khanafseh have developed a new way to calculate integrity risk, showing that not all cycle ambiguities would lead to hazardous errors. Their research evaluates the impact of the incorrect integer wavelengths directly at the receiver and, in doing so, have produced a formula to compute a theoretical tight upper bound on integrity risk. "The problem with previous thinking is that some incorrect cycle ambiguities impact position error more than others, depending on the locations of the satellites in the sky," says Pervan. "Now that we're aware that not all incorrect cycle ambiguities are dangerous, and can even predict these directly, the availability of the navigation system improves dramatically."
Find out more about the Navigation Lab.
Research Highlights: Professor David Williams
Using Gusting Flows to Power Micro Air Vehicles
Professor David Williams' research turns toward nature for its ultra-sensitive and hyper-efficient flight systems. Williams, in collaboration with Professor Tim Colonius at California Institute of Technology, aims to develop technology that mimics the biological systems some larger-sized birds utilize to soar for incredibly long distances without flapping their wings. With a view to use this technology in micro air vehicles, a type of remotely controlled aircraft that is significantly smaller than similar vehicles, Williams has been studying the manner by which birds take advantage of lifting thermal currents, extracting energy from the velocity gradients in gusting flows, even when the average of the vertical speed is zero. "On this project we are working at the intersection of fluid dynamics, flight mechanics, and controls," explains Williams, "with the hope that we can understand how birds make soaring long distances seem so easy."Find out more about the FDRC Lab.