CAREER: Theoretical Foundations of the UAS in the NAS Problem (Unmanned Aerial Systems in the National Air Space)
Award Period Date:
February 15, 2016 – November 30, 2016
Due to their increasing use by civil and federal authorities and vast commercial and amateur applications, Unmanned Aerial Systems (UAS) will be introduced into the National Air Space (NAS); the question is only how this can be done safely. Today, NASA and the FAA are designing a new, (NextGen) automated air traffic control system for all aircraft, manned or unmanned. New algorithms and tools will need to be developed to enable computation of the complex questions inherent in designing such a system while proving adherence to rigorous safety standards. Researchers must develop the tools of formal analysis to be able to address the UAS in the NAS problem, reason about UAS integration during the design phase of NextGen, and tie this design to on-board capabilities to provide runtime System Health Management (SHM), ensuring the safety of people and property on the ground. Read more.
Multi-Platform, Multi-Architecture Runtime Verification of Autonomous Space Systems
Award Period Date:
Autonomous systems are only capable of effective self-governing if they can reliably sense their own faults and respond to failures and uncertain environmental conditions. We propose to design a real-time, onboard runtime verification and system health management (SHM) framework called R2U2, to continuously monitor essential system components such as sensors, software, and hardware for detection and diagnosis of failures and violations of safety or performance rules during the mission of autonomous space systems, such as rovers, small satellites, or Unmanned Aerial Systems (UAS) flying in the skies of other planets. Read more about the research on NASA’s website.
Unraveling Silent Owl Flight to Develop Ultra-Quiet Energy Conversion Machines
Acoustic emission (noise) from wind turbines is curtailing the growth of wind energy, which is currently the primary renewable energy source in the US and in the world. A majority of the noise radiated from wind turbines is generated aerodynamically – due to interaction of wind with blade surfaces. Aerodynamic sound (aeroacoustics) is an issue not just for wind turbines but also for aircraft, jet engines, combustion turbines used for electricity generation, cooling fans, and ventilation systems.
A solution to the problem of aerodynamic noise generation is available in nature but has not yet been leveraged to develop silent machines. The nocturnal owl is known to have a silent flight both when gliding and flapping. This has been known for decades, but the physical mechanisms enabling its silent flight are not well understood. Previous investigations have identified three feather features that are unique to the owl. Experimental investigations have demonstrated that these unique feather features are responsible for the owl’s acoustic stealth. However, these experiments alone are unable to identify the reasons/mechanisms behind noise reduction.
This project supports very high resolution simulations to bridge the scientific gap between experimental results and theoretical understanding. A systematic numerical investigation of the unique owl feather features is proposed to answer key questions that will help unravel the mystery behind owl’s silent flight. The extremely high spatial and temporal resolution offered by high-fidelity numerical simulations will enable source diagnostics to identify how the unique feather features curb noise generation. The knowledge and understanding gained from these simulations can empower us to design nearly silent energy conversion-‐ and various other engineering machines.
EAGER: Collaborative Research: Lectures for Foundations in Systems Engineering
Award Period Date:
August 1, 2016-July 31, 2018
The objective of the Early-concept Grant for Exploratory Research (EAGER) collaborative project is to create a series of educational videos on foundational areas from which systems engineering theory will be able to draw. Dr. Bloebaum, along with Dr. Abbas from the University of Southern California, will promote the use of rigorous foundations in the development of a theory of systems engineering in ways that are accessible to a broad group of educators, researchers and practitioners.
For more information on the award, please visit the NSF website.
Self-Sustainable Study Abroad Programs at Xi’an Jiaotong University for U.S. Engineering Students
Award Period Date:
July 1, 2016-August 31, 2017
This is a newly developed semester-long exchange program between ISU and Xi’an Jiaotong University in Xi’an, China. Each year, equal number of American and Chinese students will spend one semester in the host universities, taking courses just like regular students. The first group of ISU students will depart in January 2017. Xi’an Jiaotong will offer Engineering courses in English, in addition to a variety of Chinese language/culture courses. No prior knowledge of Chinese language/culture is needed to enter the program. The students will be able to keep up with the regular study plan after the semester, in addition to the unique study-abroad experience and some foreign language proficiency.
Prathamesh Bilgunde, a graduate student majoring in Engineering Mechanics, received the Robert Uhrig Graduate Scholarship Award from the American Nuclear Society for his work on high temperature transducers in nuclear reactors. The scholarship, which awards students pursuing graduate research with a focus in the field of nuclear instrumentation and controls, is named after Robert Uhrig, a former Iowa State professor in the 1960’s. During his time at Iowa State, Uhrig worked in the building adjacent to where Bilgunde has been doing his research.
Bilgunde’s graduate research is funded under the Nuclear Energy University Program (NEUP) by the Department of Energy. It is a continuation of the work done by his professor, Leonard Bond, while he was at the Pacific Northwest National Laboratory in Richland, Washington.
“This transducer technology is a key to enable safe and economic operation of a liquid metal cooled reactor, and is used for under-coolant viewing and in-situ non-destructive inspection of critical components,” Bilgunde said.
Bilgunde’s goal is to understand why previous designs did not give desired performance and demonstrate a novel methodology that could significantly improve the transducer sensitivity to provide better images of the reactor under the silvery liquid metal while it continues to operate.
“If you don’t have an ultra-sonic viewing system, you’re basically flying blind inside the liquid sodium, it’s optically opaque,” Bond says. “Say you want to move fuel rods around then you would like to be able to monitor or inspect the inside of the reactor for cracks or broken parts.”
The transducers that Bilgunde is working with are not the ultrasound scanning probes that you would normally see in a medical ultrasound machine. The ultrasonic scanning capabilities needed for nuclear reactors must operate with an optimum signal to noise ratio at temperatures up to 260 degrees centigrade for eight hours, and still continue work at the end of the day.
“His task was to go beyond something that just survives, to give something that works better,” Bond said. “You can develop good phased array transducers which operate at room temperature, that part is well understood. High temperature transducers are a lot more challenging and complicated.”
The United States does not currently have a working sodium-cooled fast reactor and a working transducer is imperative for this technology to exist. China, Japan, and India are currently the only countries that have operational sodium-cooled fast reactors. Bilgunde wants to ensure that if a sodium reactor does come to the U.S., the transducer is capable of handling the rigorous workload and temperatures.
“The objective of my graduate research is to quantify each factor that causes the degradation of the transducer sensitivity at an elevated temperature.” Bilgunde said. “Using a physics based modeling approach, we have been able to quantify the causality between thermal degradation of the piezoelectric material and ultrasonic transduction. This has helped in selecting a new high temperature piezo-electric material which can give the required sensitivity at 260 degrees centigrade.
As the first Iowa State student to win this award, Bilgunde sees it as a motivator to continue his research.
“It is a nice recognition as well as an encouragement to continue the fundamental work in developing robust transducers for harsh environment” Bilgunde said.
His professor meanwhile, sees it as recognition that they are on to something big.
“In terms of sodium fast reactor instrumentation, this project is absolutely on the cutting edge,” Bond says. “It’s the leading work in the U.S., and he’s had his head down and worked really hard.”
Dr. Valery Levitas, Iowa State’s Schafer Professor of aerospace engineering and of mechanical engineering, has been named the 2016 recipient of the ISU Award for Outstanding Achievement in Research. This award recognizes faculty members for outstanding career achievements in research, outstanding national and international recognition in the academic community, and a substantial positive impact of their mentorship and/or teaching on undergraduate students, graduate students and/or postdoctoral associates.
Dr. Levitas developed the first conceptual multiscale approach for high pressure mechanochemistry. This theory predicts new methods of material synthesis (in particular, for superhard materials) and search for new materials. Notably, his team transformed boron nitride from graphite-like to superhard at record low pressure, which may serve as a precursor of new technologies.
He also discovered virtual melting as a new mechanism of crystal-crystal and crystal-amorphous phase transformations and plastic deformation at temperatures hundreds and thousands degrees below the melting temperature. Virtual melting is predicted using a developed, advanced thermodynamic approach and confirmed by large-scale molecular dynamics simulations of shockwave propagation in metals, by experiments on phase transformations in ferroelectric nanofibers, and by phase field simulations for energetic materials.
Currently, Dr. Levitas is working on two long-term projects supported by National Science Foundation and projects from Office of Naval Research, Army Research Office, and Defense Advanced Research Projects Agency.