Microgravity geyser and flowfield prediction

Modeling and prediction of flowfields and geyser formation in microgravity cryogenic propellant tanks were investigated. A computational simulation was used to reproduce the test matrix of experimental results performed by other investigators, as well as to model the flows in a larger tank. An underprediction of geyser height by the model led to a sensitivity study to determine if variations in surface tension coefficient, contact angle, or jet pipe turbulence significantly influence the simulations. It was determined that computational geyser height is not sensitive to slight variations in any of these items. An existing empirical correlation based on dimensionless parameters was reexamined in an effort to improve the accuracy of geyser prediction. This resulted in the proposal for a reformulation of two dimensionless parameters used in the correlation: the nondimensional geyser height and the Bond number. It was concluded that the new nondimensional geyser height shows little promise. Although further data will be required to make a definite judgment, the reformulation of the Bond number provided correlations that are more accurate and appear to be more general than the previously established correlation. Copyright © 2007 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved