Joseph Nahum Gray - US grants

This award provides funding to Iowa State University, under the direction of Dr. David Jiles, for the support of a Combined Research-Curriculum Development project entitled, " Vertically Integrated Engineering Design for Combined Research and Curriculum Development." This project focuses on a combination of design experience and research to meet the educational needs of future generations of engineers in the most efficient manner possible and without increasing the number of course credits needed for graduation. The mechanism devised for achieving this is termed "vertically integrated design," which will provide a broader design experience for engineering students. This approach will engage students throughout their undergraduate career, beginning with sophomores, using state-of-the-art engineering simulators that illustrate the various critical stages in the life cycle of manufactured components. The specific field of research involved is nondestructive evaluation, which combines recent advances in life-cycle engineering, modeling and strong industrial interactions through the NSF Industry/University Cooperative Research Center for Nondestructive Evaluation. Formal courses on engineering practice and design will be taught in parallel with the experimental research project, which will involve sophomores, juniors and seniors working together.

This grant will be used to develop an x-ray system to perform noninvasive three-dimensional imaging of large-scale multiphase flows. This new instrument will allow for the study, characterization, and modeling of numerous multiphase flow processes found in many industries including fuel production, commodity and specialty chemical production, mineral processing, pulp and paper production, wastewater treatment, food processing, and biological organism and pharmaceutical production.

Multiphase flows involve gas-liquid, gas-solid, liquid-solid, and gas-liquid-solid mixtures. The principle difficulty in characterizing and quantifying multiphase flows is the fact that the systems are typically opaque; even an air-water system becomes opaque at fairly low volumetric gas fractions. This necessitates either the use of invasive measurement probes when determining internal flow and transport characteristics or nondestructive (noninvasive) methods. The difficulty with invasive probes is that they can alter the internal flow of the multiphase system interfering with realistic process measurements. X-ray imaging methods provide one family of noninvasive measurement techniques used extensively for product testing and evaluation of static objects with complex structures. The project will develop an instrument that utilizes x-ray radioscopy, x-ray stereography, and x-ray computed tomography imaging techniques to characterize properties of multiphase flow processes, including those properties that are dynamic and time dependent.

The project will develop the x-ray hardware, software, and facilities to complete x-ray computed tomography (i.e., CT scans) of multiphase flows in large vertical columns, providing time-averaged local phase distributions with a typical resolution of 500 microns. The system to be developed in this project will allow for vertical columns up to 4 m high and 32 cm in diameter to be studied. These dimensions will allow for the first time, without significant interference of either wall effects or mechanical interference
from invasive probes, investigation of these industrially important systems. Various letters of support, from a variety of industries, have stressed this is a critical need. The explosion of computer power in the last three years allows for the first time the ability to acquire, process, and display the data volumes needed to adequately characterize these complex systems.

The instrumentation that will be developed will include a novel application of x-ray stereography and stereographic reconstructions to visualize time-resolved flow structures in three dimensions. This new and unique capability will allow for the measurement of currently unavailable phase characteristics found in complex multiphase flows, such as phase rise/settling velocities, phase trajectories, phase coalescence and breakup rates, and phase growth and shrinkage rates. With this instrument, data acquisition will be possible of internal characteristics of multiphase flow at a sufficient resolution to be used for model validation of these complex flows, and, to our knowledge, will provide a leading edge research capability currently unavailable at any institution.

Once this instrument is developed, many other ISU researchers, as well as industrial collaborators (e.g., Air Products and Chemicals, Inc., Cargill, Inc., DOW Chemical Company, Fluent, Inc., Foster Wheeler Development Corporation, Kimberly-Clark Corporation, Potlatch, Proctor & Gamble Company, and Schlumberger Oilfield Services), have identified many potential uses of this instrument in studying gas-liquid, gas-solid, liquid-solid, and gas-liquid-solid flows. Even traditional computed tomography and stereography of industrial components requiring a large field of view can be done with this instrument. This instrument will also provide a unique opportunity to form various multidisciplinary collaborations between faculty, academic and industrial researchers, and students, and provide a one-of-a-kind instrument at a public university to which many different researchers will have access.