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Numerical studies of the surface tension effect of cryogenic liquid heliumThe generalized mathematical formulation of sloshing dynamics for partially filled liquid of cryogenic superfluid helium II in dewar containers driven by both the gravity gradient and jitter accelerations applicable to scientific spacecraft which is eligible to carry out spinning motion and/or slew motion for the purpose of performing scientific observation during the normal spacecraft operation is investigated. An example is given with Gravity Probe-B (GP-B) spacecraft which is responsible for the sloshing dynamics. The jitter accelerations include slew motion, spinning motion, atmospheric drag on the spacecraft, spacecraft attitude motions arising from machinery vibrations, thruster firing, pointing control of spacecraft, crew motion, etc. Explicit mathematical expressions to cover these forces acting on the spacecraft fluid systems are derived. The numerical computation of sloshing dynamics has been based on the non-inertia frame spacecraft bound coordinate, and solve time-dependent, three-dimensional formulations of partial differential equations subject to initial and boundary conditions. The explicit mathematical expressions of boundary conditions to cover capillary force effect on the liquid vapor interface in microgravity environments are also derived. The formulations of fluid moment and angular moment fluctuations in fluid profiles induced by the sloshing dynamics, together with fluid stress and moment fluctuations exerted on the spacecraft dewar containers, have been derived.
Document ID
19950007691
Acquisition Source
Legacy CDMS
Document Type
Contractor Report (CR)
Authors
Hung, R. J. (Alabama Univ. Huntsville, AL, United States)
Date Acquired
September 6, 2013
Publication Date
October 1, 1994
Subject Category
Fluid Mechanics And Heat Transfer
Report/Patent Number
NAS 1.26:197014
NASA-CR-197014
Accession Number
95N14104
Funding Number(s)
CONTRACT_GRANT: NAG8-938
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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