TitleCharacterization of the flow field and shape of de-fluidized regions in the wake of large submerged objects in small particle fluidized beds
NameRao, Prakash (author), Muller, Michael R (chair), Cook - Chennault, Kimberly (internal member), NORRIS, ANDREW (internal member), Ozel, Tugrul (outside member), Rutgers University, Graduate School - New Brunswick,
SubjectMechanical and Aerospace Engineering,
DescriptionThe structure of the de-fluidized hood, an area of un-fluidized material found in the wake downstream of submerged objects, is studied with special interest on the internal fluidization structure and shape of the hood. Previously, the structure of the region was determined based on indirect photographic evidence rather than direct measurement. Also, the wake region had been considered to be entirely packed and focus had only been on the de-fluidized region in the near wake. In the present study, an experimental set-up was created which allowed for spheres and disks of various radii to be suspended within a fluidized bed of Geldart A particles. The force imparted by the wake region at various depths on a submerged object was measured providing insight into the downstream extent of the region, as well as the nature of the fluidization within the wake. Additionally, bed collapse with an object near the surface was studied to gain insight into particle mobility within the wake. Experiments were conducted to measure the maximum normal force supported by the wake region, as well as the shear and drag, at various depths above the submerged object surface providing an indirect measure of the velocity within the wake and its effect on neighboring structures. The results show the region to have several fluidization states: a dead region, a stagnant percolating region, a large percolating region of mobile particles, and an expanding region. The overall shape is found to resemble cylinder with a rounded top. Voids generated at the hemisphere of the submerged objects and particle circulation into and out of the region were found to play a key role in determining the shape and height of the hood, as well as playing a key role in the re-fluidization of the region. Using the data collected from the experiments, a model of the weight force imparted by the de-fluidized region on a submerged object was developed.
NoteIncludes bibliographical references
Noteby Prakash R. Rao
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.