Showing papers on "Ullage published in 1981"

Study of liquid slosh in the tracking and data relay satellite hydrazine tanks

Abstract: An experimental study was conducted to provide data for evaluation of the parameters for an analytical mechanical model representation of liquid/interface dynamics in the TDRSS propellant tanks. Models were developed for two liquid-under ullage (forward tank) configurations and for one liquid-over-ullage (aft tank) configuration. However, additional test runs were conducted with liquids of different densities in both cases to allow separation of bladder stiffness and gravity effects under various simulated steady acceleration conditions. Both static and dynamic parameters are evaluated to provide a good prediction of observed results.

Ullage tape winder

Abstract: An ullage gauge for directly and accurately measuring the ullage of a cargo tank of a vessel such as an oil tanker without the necessity of opening the hatch. The gauge is comprised of a calibrated ullage tape which is supplied from a winder reel positioned within a sealed chamber atop the deck of the tanker and communicating with the cargo tank, the winder reel being rotated by a winder reel handle placed exterior of said sealed chamber. The sealed chamber includes a view window which allows direct observation of the calibrated surface of the ullage tape as well as direct observation of the rising cargo within the cargo tank. A float attached to the ullage tape is of sufficient size and weight that once contact of the float with the surface of the cargo is made, such contact is felt by the operator through the winder reel handle.

Prediction of sloshing loads in LNG ships

Abstract: To improve LNG-sloshing prediction methodology, researchers studied high-fill-ratio sloshing phenomena via computer models and developed the MDC 2D slosh code, which accounts for large-amplitude sloshing, interaction with tank ceiling and chamfers, and liquid compressibility. Application of the MDC code showed that computer programs based on the marker-and-cell technique can serve as practical design and research tools. The analytical results demonstrated that (1) for realistic random ship motions, increasing the chamfer size is beneficial and (2) under pure vacuum ullage conditions, the inability to properly scale liquid compressibility in model tests requires the use of compressible pressure scaling laws. The good correlation between liquid surface motion and code predictions verified the accuracy of both the code and Froude scaling for liquid motions.