Fluid Merging Viscosity Measurement (FMVM)
Research Area: Fluid Physics
Expedition(s): 9 and 11
Principal Investigator(s): ● Edwin C. Ethridge, PhD, NASA’s Marshall Space Flight Center,
Huntsville, Alabama
RESEARCH OBJECTIVES
Fluid Merging Viscosity Measurement (FMVM) is designed to test a new method for measuring
the viscosity of high-viscosity materials by measuring the time it takes 3 nearly free-floating
drops of a liquid to merge. The materials used are of known viscosities (corn syrup, glycerin,
and silicone oil) so that the accuracy of the fluid merging test can be compared to the methods
used on Earth. The FMVM experiment can lead to a greater understanding of glass formation
from melted lunar soil. It will also lead to a better understanding of liquid phase sintering
processes for in-space fabrication methods that can be used for constructing surface habitat
structures.
EARTH BENEFITS
This new viscosity
measuring process is
ideally suited for use
with difficult glass
forming liquids. It can
be used to make
measurements that are
impossible by other
methods. The droplet
merging method of
viscosity measurement
might be applied to
small glass samples
melted in terrestrial
containerless levitation
processing facilities. It
will also be possible to
measure the viscosity of
undercooled liquids much
more rapidly than with other viscosity methods. Methods being developed by the FMVM
experiment will make it possible to determine the viscosity of highly undercooled viscous glassy
liquids at temperatures impossible with current methods. New methods to measure viscosity at
very low shear rates also has technological significance. This method should permit the
investigation of the non-Newtonian viscosity behavior of glasses at very low shear rates. Such
viscosity data will be very useful for the modeling of crystallization behavior of materials of
scientific interest. Examination of the droplet shape changes with time can also lead to a better
understanding of terrestrial industrial and in-space processes. The coalescence of drops has
This image shows two 4 ml silicone oil viscosity standard liquid drops in the
process of coalescing to a single spherical drop. Marshall Space Flight Center
image.