Simulation of Geophysical Fluid Flow under Microgravity-II (Geoflow-II)
Research Area: Fluid Physics
Expedition(s): 25-ongoing
Principal Investigator(s): ● Christoph Egbers, Brandenburg University of Technology,
Cottbus- Senftenberg, Germany
RESEARCH OBJECTIVES
Simulation of Geophysical Fluid Flow under Microgravity-II (Geoflow-II) studies heat and fluid
flow currents within the Earth’s mantle. Geoflow-II aims to improve computational methods
that scientists and engineers use to understand and predict the processes in the Earth’s mantle
that lead to volcanic eruptions, plate tectonics, and earthquakes.
EARTH BENEFITS
Understanding how the mantle flows is a major interest for geophysics because it could help to
explain earthquakes or volcanic eruptions.
SPACE BENEFITS
A better understanding of this type of fluid flow could benefit the manufacturing methods of
spherical gyroscopes, bearings, and
centrifugal pumps for Earth and space
applications.
RESULTS
Using a spherical geometry set-up,
experiments on electro-hydrodynamic
driven fluid convection have been
performed for both temperature-
independent (GeoFlow-I) and
temperature-dependent fluid viscosity
properties (GeoFlow-II) with a measured
viscosity contrast ratio of up to 1.5.
Numerical simulations in three-
dimensional spherical geometry were
also carried out to reproduce the results
obtained in the GeoFlow experiments.
Observed flow patterns were distinctly
different between these 2 experiments.
A sheet-like thermal flow was seen in
GeoFlow-I. For this case, convection
patterns have been successfully
reproduced by three-dimensional numerical simulations using 2 different and independently
developed simulation programs. By contrast, plume-like structures were observed with GeoFlow-
II. Interestingly, numerical simulations do not yield this type of plume for the low-viscosity
contrast. However, using a viscosity contrast of 2 orders of magnitude (or higher) in the numerical
Geoflow-II image showing plume-like thermal upwellings. ESA
image.