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Executive Summary
Pages 1-8

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From page 1...
... The committee will look specifically at mission enabling and enhancing technologies which, for development, require an improved understanding of fluid and material behavior in a reduced gravity environment. These might range from construction assembly techniques such as welding in space, to chemical processing of extraterrestrially derived fuels and oxygen.
From page 2...
... PHENOMENA IDENTIFIED AS AFFECTED BY OR DOMINANT IN REDUCED GRAVITY Phenomena that are identified as underlying HEDS-enabling technologies and that either are directly affected by gravity level or emerge as dominant factors in reduced gravity are generally organized in Chapter IV of this report as follows: (1) surface and interracial phenomena, referring to effects stemming from surface wetting and interracial tension; (2)
From page 3...
... The committee's recommendations, which are based on the critical issues underlying the technologies, call for research on the following topics: · The physics of wetting, with an emphasis on hysteresis effects, the dynamics of the wetting process, and the molecular basis of wetting, to elucidate the wetting of both solid and porous media (e.g., wicks and nanoscale media) and to provide a basis for the choice of material combinations and conditions for optimal wetting and wetting agents; and · Capillary-driven;flows, with modeling of the flows induced by the Marangoni effect, which are complicated because of the feedback between the flow and the surface temperature and composition gradients that drive the flow.
From page 4...
... The following research is recommended: · The development of models and the collection and analysis of stability data on boiling and condensing systems at fractional gravity and microgravity levels. In particular, the effect of gravity level on excursive instabilities, as well as on those dynamic instabilities that can be induced by compressibility and lags in the propagation of density waves around closed loops in multiphase systems, needs to be investigated and analyzed.
From page 5...
... These phenomena, listed below in no particular order, were judged to be somewhat less critical to mission success, so the research has a lower priority. · Marangoni material parameters; · Static equilibrium capillary shapes; · The effect of gravity on convective condensation heat transfer; · The effect of gravity on the heat transfer characteristics of fluid flow in porous media; · The transport of flame suppressant to fires in reduced gravity; · Diffusion-flame structure of fuels and flame products as affected by gravity levels;
From page 6...
... Department of Energy-Naval Reactors program for help in designing research programs aimed at developing the required multivariate, physically based computational models. Coordination of Research and Design The NASA office responsible for microgravity research should diligently inform NASA at large about the issues of reduced gravity that are foreseen for space hardware design, so that such considerations may enter design thinking at the concept stage.
From page 7...
... In particular, the ISS can play an important role in the multiphase flow and heat transfer research program recommended above. Peer Review for Reduced-Gravity Research The NASA Research Announcement process and its peer review system have greatly enhanced the productivity and quality of NASA's gravity-related research.


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