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Experimental investigation of vibration-induced bulk solids transport and segregation. Final technical report, March 28, 1995--September 26, 1996

Description: We report experiments on the rise time T of a single large sphere within a sinusoidally vibrated bed (amplitude a) of uniform particles (diameter d). At fixed acceleration, three distinct behavioral regimes are identified both from visual observations and from the typical increase of T with frequency f. Two convective regimes separated by a critical frequency are found, and for low a and high f, a {open_quotes}non-convective{close_quotes} regime. In the latter, the bed crystallizes and a size dependent rise is evidenced. The relevance of the non-dimensional parameter a/d is shown and a scaling law is deduced which has the form f {proportional_to} d{sup {minus}1/2}
Date: January 12, 1997
Creator: Plasynski, S.; Rosato, A.D. & Dave, R.N.
Partner: UNT Libraries Government Documents Department

Experiments using non-intrusive particle tracing techniques for granular chute flows. Final report

Description: The objective of this contract was to develop a system capable of non-intrusively tracking the motion of an individual particle for the study of granular flows down inclined chutes. The result of the project is a system capable of following the three-dimensional translational and rotational motion of an individual particle embedded with a flowing granular material. The basic system consists of a sphere embedded with three orthogonal transmitters emitting at different frequencies which induce voltages in an antenna array surrounding the flow regime. Analysis of the induced voltage signals within the framework of a derived model yields both the position and orientation of the sphere. Tests were performed in a small scale model chute as well as in a cylindrical vibrated granular bed, which clearly demonstrates the capability of the system. As a result of discussions at meetings held semi-annually for the Granular Flow Advanced Research Objectives (GFARO) contractors, it was deemed necessary to pursue an additional experimental program as part of this contract related to the measurement of sphere collision properties. The outcome of the work (reported in Appendix C) is the determination of certain properties which are needed for use in computer simulations and theory.
Date: December 31, 1998
Creator: Rosato, A.D.; Dave, R.N. & Fischer, I.S.
Partner: UNT Libraries Government Documents Department

[Pre-Freshman Enrichment Program]. Final report

Description: Part of the problem of the under representation of minorities in science and engineering is the unfamiliarity of young people with the role of science and engineering in urban life. This compounds the pressing need of blacks and Hispanics to take leadership positions in such areas as transportation, planning, and the environment. Objective of the urban engineering program at the New Jersey Institute of Technology is to introduce students to the excitement of science and engineering as potential career opportunities. Through the course work, workshops, projects, guest speakers, and laboratory experiences, the students are not only introduced to problems in urban areas, but also are introduced to the tools available to solve such problems. Courses included mathematics and science, architecture/urban planning, transportation, energy systems and environment, computer science, technical writing and communication, and urban design.
Date: September 1, 1995
Partner: UNT Libraries Government Documents Department

Development of a non-intrusive particle tracing technique for granular chute flows

Description: The development of a non-intrusive particle tracking system to follow the trajectory of an individual particle in three dimensions within a mass of particles is necessary to experimentally validate developing theories of inclined chute granular flows in conjunction with particle dynamics models. An understanding of the exact nature of such flows is of critical importance to a variety of industries concerned with solids handling, as well as in natural geological events. The tracking system, based on the principle of radiosonde'' transmitters coupled to receiving antennae by magnetic induction, is being developed. The radiosonde consists of one or more, orthogonally placed miniature circuits with integral loop antennas, mounted into a sphere of approximately 3/4 in. in diameter. The radiosonde sphere position can be traced during the flow down a chute by analyzing the induced voltage signals in the three or more external orthogonal receiving loop antennas due to the transmitter chips. 22 refs., 15 figs.
Date: January 1, 1992
Creator: Rosato, A.D.; Dave, R.N.; Fischer, I.S. & Carr, W.N.
Partner: UNT Libraries Government Documents Department

(Particulate Flow Research Lab) quarterly progress report, July 1, 1991--September 30, 1991

Description: Research at the Particulate Flow Research Lab continued. In the previous report it was mentioned that an anticipated change in the sphere diameter necessitated a resizing of the chute components. A check has indicated that the increased size has added enough weight to require a re-evaluation of the stresses requiring stronger fasteners. Mathematical formalism is given for the chip radiation model, and signal processing of the radiation received from the transmitting chips has been improved. A prototype apparatus has been designed and built in order to collide two identical spheres at a point in space. 4 figs.
Date: October 15, 1991
Creator: Rosato, A.D.; Dave, R.N.; Fischer, I.S. & Carr, W.
Partner: UNT Libraries Government Documents Department

Experimental investigation of vibration-induced bulk solids transport and segregation. Quarterly report ending March 31, 1996

Description: An experimental investigation of the motion of a single large sphere in a bed of dry granular material subjected to vertical vibration is presented. We have studied the rise time of the sphere as a function of vibration parameters, frequency and amplitude. While previous results report a decreasing rise time with increasing relative acceleration, we evidence the existence of a critical frequency where the rise time jumps to greater values before decreasing again. We also show that the rise time scales with the velocity amplitude of vibration and the transition corresponds approximately to a doubling of rise time. The results reported are over a rather narrow range of input accelerations, and generally involve gross phenomena of heaping and fluidization. Observations of the dynamic trajectory of the rising particle are also reported through the use of a novel non-intrusive particle tracking system. 16 refs., 7 figs.
Date: September 1, 1996
Creator: Rosato, A.D. & Dave, R.N.
Partner: UNT Libraries Government Documents Department

Experimental investigation of vibration-induced bulk solids transport and segregation. Quarterly technical progress report, April--June 1995

Description: In the first phase of this research, we have finished the simulation studies to support the experimental work in the area of particle transport in vibrated granular beds. Representative results are briefly summarized in the attached short paper. Based on the results obtained, in particular the interesting phenomena such as heaping, arching and bifurcation in the flow regime, we have decided to carry put the initial set of experiments in a two dimensional rectangular bed. A schematic diagram of this is also attached. This rectangular cell will allow us to make the necessary observations, in particular the optical observations made through the use of Kodak EkatPro1000 high-speed video camera. A student, supported by the Institute as a match to this grant is in tile process of completing the fabrication of this cell, and has collected all the pertinent literature in this area. We have also obtained specifications and quotations for the vibration unit to be used in this experiments, and it will be ordered in the near future. In addition to the use of the two dimensional rectangular bed, we have also developed a three dimensional cylindrical cell for the study of segregation behavior. A nonintrusive tracking system will be used in measuring the trajectories of tile rising large particle, and at present all the calibration jigs, and software have been developed. We anticipate collecting the experimental data in the next few weeks.
Date: May 1, 1996
Creator: Rosato, A.D. & Dave, R.N.
Partner: UNT Libraries Government Documents Department