Graduation date: 1995

The Fraser River plume is the brackish surface layer formed when the Fraser River discharges into the Strait of Georgia. Two approaches to understanding the dynamics of the plume are discussed. Initially, a series of field observations was carried out in the plume. These consisted mainly of CSTD profiles and current profiles in the upper 10-20 meters of the water column. Also, a surface current meter was installed for 34 days at the mouth of the Fraser River. The principal conclusions of the field observations are: the plume is strongly sheared in the vertical and strongly stratified; this vertical structure is most apparent in the vicinity of the river mouth, and around the time of maximum river discharge (near low water in the Strait); and that the water moving outward from the river mouth subsequently acquires velocities and salinities appropriate to the water beneath it with length and time scales for this change of order 50 km and 8 hours. The plume thickness varies between 0 and 10 meters; the salinity varies from 0 to that of the water beneath it (approx. 25 ‰); and the difference between the plume velocity and that of the water beneath it varies from up to 3.5 m/sec to 0 m/sec, and is typically of order 0.5 m/sec over much of the plume area. Inspired by the field data, a model of the thin upper layer was developed. The independent variables are the two components of transport in the upper layer, the thickness of the layer, and the integrated salinity in the upper layer. The bottom of the upper layer has been tentatively defined by an isopycnal surface. The mixing across this interface is modelled by an upward flux of salt water (entrainment), and a downward flux of brackish water (termed depletion in this work). The dynamical effects included in this model are: the local time derivative; the field accelerations; the buoyant spreading pressure gradient (including the effects of salinity on the density field); the entrainment of tidally moving water and the loss by the depletion mechanism of water with the plume momentum; the frictional stress between the plume and the water beneath it; the forcing due to the baroclinic tidal slopes; and the Coriolis force. Subsets of the full model equations are examined, to clarify certain aspects of the plume dynamics. Preliminary results from the numerical solution of the full model eguations are presented, and a comparison is made between the paths of lagrangian trackers produced by the model and drogue tracks observed in the plume. Future improvements to the model are discussed. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

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Graduation date: 1994

Thesis (Ph. D.)--University of Alberta, 2009. / Title from pdf file main screen (viewed on Dec. 22, 2009). "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Applied Mathematics, Department of Mathematical and Statistical Sciences, University of Alberta." Includes bibliographical references.

Thesis (Ph. D.)--Joint Program in Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2001. / "September 2001." Vita. Page 223 blank. Includes bibliographical references.

Rocket plume flowfields have an importance due to their influence on the signature of the rocket and also on the distribution of the plume gases around the vehicle. Little information on the co-flowing situation exists other than a previous study at Oxford. This thesis thus represents a significant database for co-flowing rocket plumes of this form. The work presented deals with two new aspects of co- flowing rocket plumes in that detailed flowfield measurements have been made and plumes from twin nozzle have been investigated for the first time in this thesis. This study on twinjet rocket plumes was carried out using the University of Oxford Gun Tunnel. Twinjet rockets with nozzle exit Mach numbers of 3 and 5 were tested in quiescent and in co-flow at Mach 7 using nitrogen and hydrogen injections. A major feature of the twinjet case was the so-called impingement shock between the flows from the two nozzles. It was discovered that this shock was insensitive to the freestream and scaling parameters are suggested for its geometry. Comparisons with single equivalent thrust nozzles are made at downstream locations and similar Pitot pressure profiles were observed for nitrogen injection in a nitrogen freestream after approximately 3 nozzle diameters downstream. Shear layers were studied and fluctuations in this region were measured by fast-response Pitot pressure and heat transfer probes sampled at 1.1 MHz. The extent of the shear layer was deduced using a new Oxford Total Temperature Probe. With the freestream stagnation temperature at approximately 650 K and injected gas at 350 K, a linear variation for the deduced total temperature across the shear layer was obtained. This was consistent with the Pitot pressure variations across this region. Convective heat transfer coefficient fluctuations and flow total temperature fluctuations across rocket flowiields were obtained using three thin-film heat transfer probes and found to be closely correlated. Experimental results for the twinjet and the single jet were compared with CFD simulations and good overall agreements were achieved. Instrumentation for the hypersonic experiments was investigated and a fast-response (~ 20 kHz) Pitot probe suited for flows heavily contaminated with particulate was developed and tested.