S.C.O.P.E.

"Simulation for Confirmation of the Onset Correlation of Liquid Potassium Entrainment"

 

2005-2006

 

Experiment Abstract:

The year 2004 has already marked some major changes in this nation’s space policy.  In January, President Bush announced a new vision for NASA that includes sending mankind back to the moon by 2020 in preparation for a more ambitious human expedition to Mars.  The need for a reliable and continuous source of large amounts of electricity to support such endeavors points to nuclear fission.  Indeed, in the near term, the Jupiter Icy Moons Orbiter (JIMO) program aims to demonstrate the use of a space-based nuclear fission reactor for the generation of electricity and propulsion.  Clearly, to support these objectives, the scientific community must focus upon the design and operation of space-based nuclear reactors along with their associated power conversion systems

Higher levels of nuclear electric power generation require dynamic power conversion systems such as the Rankine, Brayton, and Stirling thermodynamic cycles.  A Rankine cycle using potassium as the working fluid offers particularly attractive potential.  Several key technological design issues remain, however, including two-phase fluid management in microgravity.  One such issue involves the phenomenon of fluid entrainment.

As part of the 2004 NASA Reduced Gravity Student Flight Opportunity Program, this experiment plans to validate, under microgravity conditions, the Ishii and Grolmes Entrainment Onset Correlation, which was obtained under normal gravity conditions, or propose a new correlation for concurrent two-phase fluid flow in a smooth pipe under microgravity conditions.  Also, this experiment plans to expand the known data set for entrainment via the investigation of entrainment onset for concurrent two-phase fluid flow in a smooth pipe with a twisted tape insert.  While water and air will serve as the working fluids for this two-phase flow experiment, care is taken in the experiment design to ensure that the results can provide insight into a liquid potassium fluid system under the conditions experienced in a proposed space-based boiler.

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