FEASIBILITY OF ROTATIONAL DESTRATIFICATION OF SPACE-STORED LIQUID CRYOGENS

Abstract

A method is presented for determining the onset of a thermally induced convective mixing motion in a model of a cylindrical space-storage tank subjected to a constant heat flux at its outer boundary. The model simulates a completely filled liquid cryogen tank with shear-free ends rotating in a low- gravity environment. The governing disturbance equations reduce to a self-adjoint eigenvalue problem for the critical Rayleigh number (the stability criterion). Using the Rayleigh-Ritz technique of approximating eigenvalues with an equivalent variational principle, the critical Rayleigh number is calculated as a function of the Taylor number (ratio of Coriolis forces to viscous forces) and the aspect ratio (length-to-diameter ratio) of the cylindrical tank. Results indicate that the critical Rayleigh number is a monotonically increasing function of Taylor and a monotonically decreasing function of aspect ratio. It is found that relatively small rotational speeds will initiate and maintain a thermally destratifying convective motion within a vessel filled with liquid hydrogen. This method of mixing has the advantage of having no moving parts within the tank. It also provides a means for thermal control of space- storables.

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Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1968
Accession Number
AD0674585

Entities

People

  • Ivan Catton
  • Michael Sherman

Organizations

  • RAND Corporation

Tags

Communities of Interest

  • Ground and Sea Platforms
  • Space

DTIC Thesaurus Topics

  • Air Force
  • Aspect Ratio
  • Boundaries
  • Control Systems
  • Eigenvalues
  • Elements
  • Environment
  • Equations
  • Heat Energy
  • Heat Flux
  • Hydrogen
  • Liquid Hydrogen
  • Mechanics
  • Space Missions
  • Spacecraft
  • Storage Tanks
  • United States

Fields of Study

  • Physics

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Fluid Dynamics.
  • Structural Dynamics.

Technology Areas

  • Space
  • Space - Hall-Effect Thruster