Most AUVs, and particularly Autonomous Underwater Gliding Vehicles (AUGV), must remain in motion or maintain neutral buoyancy at controlled depths with little or no propulsion. The ability to be both mobile and bottom-resting creates many desirable features in a glider. A mobile to stationary conversion will allow a traditional, bottom mounted sensor platform to be deployed from over the horizo...

In the major ocean basins, diapycnal mixing upwells dense Antarctic Bottom Water, which returns southward and closes the deepest cell of the meridional overturning circulation (MOC). This cell ventilates the deep ocean and regulates the partitioning of CO2 between the atmosphere and the ocean. Our conceptual understanding of the deep stratification and MOC has evolved from classic “abyssal reci...

It has been recently recognized that the nonisothermal conditions present in physical vapor transport ampoules can give rise to a slip flow of gas over the side walls of the ampoule. This phenomenon, known as thermal creep, is usually insignificant relative to buoyancy-induced flows under similar nonisothermal conditions, and has therefore been neglected in previous PVT numerical models. Howeve...

The present numerical study is concerned with the fundamental physics of the multi-way interaction between turbulence, chemical reaction and buoyancy in a nonpremixed flame. The method of direct numerical simulation (DNS) is used to solve the instantaneous three-dimensional governing equations. Because of the present supercomputer limitations, we consider two simple flow geometries, namely an i...

A two-week dataset from a partially and periodically stratified estuary quantifies variability in the turbulence across the tidal and spring–neap time scales. These observations have been fit with a twoparameter model of the Reynolds stress profile, which produces estimates of the time variation of the bottom boundary layer height and the friction velocity. Conditions at the top of the bottom b...

The field effects of buoyancy on laminar and turbulent premixed v-flames have been studied by the use of laser Doppler velocimetry to measure the velocity statistics in +1g, -1g and μg flames. The experimental conditions covered mean velocity, Uo, of 0.4 to 2 m/s, methane/air equivalence ratio, φ, of 0.62 to 0.75. The Reynolds numbers, from 625 to 3130 and the Richardson number from 0.05 to 1.3...

It is well known that buoyancy has a major influence on the flow structure of turbulent nonpremixed jet flames. For example, previous studies have shown that transitional and turbulent jet flames exhibit flame lengths that are as much as a factor of two longer in microgravity than in normal gravity. The objective of this study is to extend these previous studies by investigating both mean and f...