Sinking a body with bubbles in closed and open environments
DeGrace, Carl W.
MetadataShow full item record
The presence of bubbles in a liquid decreases the average density, and thus decreases the buoyant force on a floating body. Competing with the decrease in buoyancy is an upward drag due to the bubble motion and entrained liquid. This thesis presents investigations of the critical average density required to sink a buoyant body in water with bubbles in closed and open environments. A closed environment is where bubbles fill the container, in which case there is expected to be little if any upward flow of water at the body. An open environment is where the bubbles exist over a small cross-sectional area compared to the total cross-sectional area of the container, which models the effect of a methane eruption from the ocean floor. In this case, a substantial upward flow of water is entrained in the region of the bubbles, and a downward flow consequently occurs outside this region. Experiments for both closed and open environments are reported, where the average specific gravity of the body is varied. The closed environment data significantly deviate from a quantitative theory, and the open environment data are not in accord with a qualitative theory. Possible explanations for these deviations are offered.
Showing items related by title, author, creator and subject.
Pringle, Leonard B. (Monterey, California. Naval Postgraduate School, 2000-06);The introduction of gas bubbles into a liquid decreases the average density, and thus decreases the buoyant force on a floating body. This thesis investigates the critical average density required to sink a buoyant body ...
Tuite, Joseph M. (Monterey, California. Naval Postgraduate School, 1999-03);The boiling of a highly wetting dielectric fluid, in an oscillating environment, has been investigated. Because of low surface tension, these liquids require very high superheat to initiate nucleate boiling. This high ...
Turk, Ugur. (Monterey, California. Naval Postgraduate School, 1995-12);In the present study, boiling of highly wetting dielectric fluid has been investigated in an oscillating Fluid environment. A piston is designed to create oscillations in the fluid and over a heated platinum wire. Because ...