Thesis (Ph. D.)--Flinders University of South Australia, 1994. / Includes bibliographical references (leaves 272-277).

Thesis (Ph.D)--Aerospace Engineering, Georgia Institute of Technology, 2010. / Committee Chair: Menon, Suresh; Committee Member: Lieuwen, Timothy C.; Committee Member: Sankar, Lakshmi; Committee Member: Stoesser, Thorsten; Committee Member: Syed, Saadat; Committee Member: Walker, Mitchell. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Thesis (Ph.D.)--University of Rhode Island, 2009. / Includes bibliographical references (leaves 103-105).

Thesis (Ph. D.)--Florida State University, 2005. / Advisor: Dr. William K. Dewar, Florida State University, College of Arts and Sciences, Dept. of Oceanography. Title and description from dissertation home page (viewed Sept. 23, 2005). Document formatted into pages; contains ix, 100 pages. Includes bibliographical references.

Thesis (Ph.D.)--University of Iowa, 2006. / Supervisors: George Constantinescu, Larry J. Weber. Includes bibliographical references (leaves 288-296).

Thesis (S.M.)--Joint Program in Physical Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2006. / Includes bibliographical references (p. 139-143).

M.Ing. (Mechanical Engineering) / Shell and tube heat exchangers are commonly used in industrial processes. In the heat exchangers the tubes incur flow induced vibrations. These vibrations lead to fretting on the perimeter of the tube at the baffle plates and to fatigue failure at the tube sheets. Various studies were and are done to qualify and quantify these vibrations. This is then used to develop design criteria and methods for lowering the vibration amplitudes of the tubes. In the thesis the response of a tube bundle in cross flow is shown. The effect of increasing cross flow velocity on the vibration amplitude of the tubes is determined in a low speed wind tunnel. The results show similarity to the work done by Gorman [27]. By raising the natural frequency of the tubes in the first row upstream it is shown that the vibration peaks exhibited by the unmodified model.at cross flow velocities lower than the critical flow speed do not materialize in the modified tube bundle. This modification can be implemented by decreasing the unsupported length of the tubes in the first row. The inclusion of fluid damping when calculating the total damping of the tubes according to Blevins [24] is shown in the experiment. From experimental results it is shown that the prediction of the critical velocity according to Blevins [24] results in a better prediction of this velocity. Numerical solutions of two dimensional flow over a single cylinder and a pair of cylinders are obtained by simulating the flow on the STAR CD flow simulation package. The effect of neighbouring tubes on one another is determined by qualifying and quantifying the flow over and the forces on the tubes. The vortex shedding frequency determined from the simulation coincides with experimental results. This shows great potential in future simulation of flow over a tube bundle. A computerised design model is also developed. Themodel determines the vibration potential of the tube bundle in a shell and tube heat exchanger. If needed, modifications to new designs and built heat exchangers can be done and the vibration potential is easily determined with the model. The results of the experimental work are used to further develop the design criteria preventing detrimental vibrations in heat exchangers. Promising results to decrease vibration amplitudes of tubes in tube bundles are obtained in the experiments done. This and the results obtained in the simulation of the vortex shedding frequencies that coincide with the results in the experimental work, show great potential for flow simulation and development of methods to decrease flow induced vibrations of tubes in shell and tube heat exchangers.

No description available.

The knowledge of the ocean environment, especially its littoral/coastal waters, is important for current and future naval operations. In particular, an accurate description of the mesoscale variability of the surface and subsurface currents is essential for optimizing Navy missions. This study determines that different types of topographic smoothing and the addition of a volume constraint to a sigma-coordinate model significantly influences the generation, evolution, and maintenance of not only the surface and subsurface currents, but also other features (upwelling, meanders, eddies, filaments, Mediterranean Outflow, and Meddies) in the Northern Canary Current System (NCCS). The NCCS is chosen for this study for its classical upwelling and equatorward surface current as well as the unique impact of the Mediterranean Outflow. The sound speed structure of these features is examined to establish which regions of the NCCS experience the largest changes in sound speed and the most intense gradients. This study demonstrates that features of classic littoral/coastal eastern boundary current systems, like the NCCS, have an important impact on the sound speed structure which can significantly impact Navy sonar operations.

Thesis (Ph. D.)--Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1984. / Includes bibliographical references (p. 175-181).