Investigation of the effect of a circular patch of vegetation on turbulence generation and sediment deposition using four case studies
Ortiz, Alejandra C.
MetadataShow full item record
This study describes the spatial distribution of sediment deposition in the wake of a circular patch of model vegetation and the effect of the patch on turbulence and mean flow. Two difference types pf vegetation were used along with two different stem densities totaling four different case studies. The spatial location of enhanced deposition correlated with the steady wake zone, which has length, L1. The steady wake zone only occurred downstream of the rigid emergent patches of vegetation and was not seen downstream of the flexible submerged patches of vegetation. The enhanced deposition occurred when both turbulence and mean velocity was below the upstream, initial values. The enhanced deposition occurred when the mean velocity was less than or equal to half of the initial velocity. For the four cases studied, theses parameters of low velocity and low turbulence were primarily met within the steady wake region immediately downstram of the two rigid emergent patches of vegetation. In all four cases, large coherent structures are created in the flow due to the patch. Lateral vortices are formed downstream of the patch in a von-Karman vortex street that meets at the center of the flow a distance, Lw, downstream of the patch. For the flexible submerged cases, streamlines reattach to the bed of the flume a distance, Lv, downstream of the patch. In addition, for the flexible submerged cases, a secondary circulation is generated with flow moving laterally away from the patch at the surface and toward the centerline of the patch at the bed.
Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June 2012
Showing items related by title, author, creator and subject.
Nadakuditi, Rajesh Rao (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2007-02)The first part of the dissertation investigates the application of the theory of large random matrices to high-dimensional inference problems when the samples are drawn from a multivariate normal distribution. A longstanding ...
Alpert, Alice (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2016-09)Paleoclimate archives place the short instrumental record of climate variability in a longer temporal context and allow better understanding of the rate, nature and extent by which anthropogenic warming will i ...
Christeson, Gail L. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1994-02)This thesis is concerned with understanding how oceanic crust is emplaced at mid-ocean ridges. The emphasis is upon fast-spreading ridges, and the use of seismic techniques to image the uppermost several hundred meters ...