Energy dissipation due to sloshing liquid in torus shaped nutation dampers is studied using the potential flow model with nonlinear free surface conditions in conjunction with the boundary layer correction. Special consideration is given to the case of resonant interactions which were found to yield interesting damping characteristics. An extensive test program with the dampers undergoing steady-state oscillatory translation is then undertaken to establish the optimal damper parameters. Low liquid heights and large diameter ratios with the system operating at the liquid sloshing resonance are shown to result in increased damping, while low Reynolds numbers and presence of baffles tend to reduce the peak efficiency by restricting the action of the free surface. Tests with two-dimensional as well as three-dimensional models in laminar flow and boundary layer wind tunnels suggest that the dampers can successfully control both the vortex resonance and galloping types of instabilities. Applicability of the concept to vertically oscillating structures such as transmission lines is also demonstrated with dampers undergoing a rotational motion about their horizontal axis. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate

No description available.

No description available.

Thesis (Ph. D.)--University of Washington, 1996. / Vita. Includes bibliographical references (leaves [75]-81).

"Winds aloft are normally determined from the horizontal projection of an ascending balloon's path on a polar diagram. This method obtains a value for the average wind speed and direction for the layer through which the balloon has ascended during a two-minute interval by drawing a straight line between the horizontal projection of the balloon's position at the beginning and end of the two-minute interval. The horizontal projection of a balloon's actual path is a smooth curve and it is believed that a more accurate measurement of the average wind speed and direction for the layer will be obtained by determining the wind speed from the length of the curve for the two-minute interval and determining the direction from the tangent to the balloon's position along the curve at the intermediate time interval. The wind speed was computed by both methods for three months' data and the results compared with the purpose of determining a correction factor. The wind direction as determined by the method suggested was found not to vary appreciably from the direction determined by the conventional method. It was found that there is often a considerable difference in the wind speed as determined by the two methods especially at very low wind speeds, with the wind speed determined by the conventional method always being too small, but that it is impractical to apply a correction factor to reported winds when one considers the absolute value, rather than the percentual value, of the difference"--Abstract. / Typescript. / "August, 1956." / "Submitted to the Graduate Council of Florida State University in partial fulfillment of the requirements for the degree of Master of Science." / Includes bibliographical references (leaf 16).

Thesis (Ph. D.)--University of California, San Diego, 1998. / Vita. Includes bibliographical references (leaves 174-177).

Thesis (M.S.)--Florida State University, 2004. / Advisor: Dr. James J. O'Brien, Florida State University, College of Arts and Sciences, Dept. of Meteorology. Title and description from dissertation home page (viewed Sept. 24, 2004). Includes bibliographical references.

Typescript. / Digitized by Kansas State University Libraries

No description available.

No description available.