Gas permeability and mechanical properties of dust grains at hyper- and zero-gravity

Two-phase flow experimental data obtained from the TEMPusVoLA facility over the course of three Zero-gravity parabolic flight campaigns (PFCs). The experiment, designated 'System 1' , contains low-pressure gas and analogue dust particles (of diverse compositions, shapes, and sizes) that experience a low-pressure gas cross-wind normal to the gravitational force vector. During steady flight, the particles pack into the lower end of the chamber and the layer of granular media creates a pressure differential, which is used to extract permeability coefficients in both the continuum and molecular-diffusion dominated regimes. We compare the permeability both with and without the effect of gravity and make comparisons with the conditions on low-gravity objects in the solar system, such as planetesimals and the dust particles that comprise them.  In particular, we are able to compare and contrast the cohesiveness of the dust-regolith analogue types, which has consequences for formation theories of Solar-system bodies. 

Data products:

Pressure, acceleration

Each file corresponds to a particular parabolic flight campaign and day of flight. The 4th Swiss PFC lasted 1 day in 2020. The 75 ESA PFC lasted 3 days in 2021, and the the 78th ESA PFC lasted 3 days in 2022. Data was obtained in System 1 during all flights of all campaigns, and for a set of 12-16 parabolas. On each parabola, we studied the sample in one out of three chambers and changed the gas mass flux rate after cycling through all three samples. The below files were used to correlate changes in sample gas permeability with changes in gravitational loading. 

-- Raw pressure files output from 6-channel pressure logger measuring pressure as function of time as .csv files: DATALOG_DATE. 

-- Raw acceleration files output from accelerometer measuring gravitational load on aircraft.

Imaging data

-- Movie sequences obained with high-resolution thor-labs camera. All three chambers were imaged, despite only one chamber being subject to active gas flow at any given time. movie1 and movie 2 are referenced in the associated publication. 

Multimeter data

-- Output from photo-diodes measured across 9 channels using a Keithley Multimeter/Multiplexor.  Acquisition speed was 27 Hz.