Particle Vibration, an Instrument to Study Particle Accumulation Structures On Board the International Space Station

Abstract

The scientific and technological aspects of the PARTICLE VIBRATION Project (also known as T-PAOLA i.e. “Thermovibrationally-driven Particle self-Assembly and Ordering mechanisms in Low grAvity”) are described in detail. The project relies on the combined use of the Selectable Optical Diagnostics Instrument (SODI), a Class-2 device developed by ESA for scientific experiments in the field of fluids on board the International Space Station, and the Microgravity Science Glovebox (MSG), a Class-1 general purpose facility under the responsibility of NASA. The related modular architecture has recently been expanded under the umbrella of new scientific research funded by the UK Space Agency to allow for a novel class of experiments dealing with multiphase (solid-liquid) flows. The final aim of this microgravity project is the identification of new dispersed-phase self-organization phenomena driven by the application of vibrations and the ensuing development of new contactless particle manipulations strategies. In the present paper, emphasis is given to the related space hardware and software, the experiment protocol, the ground tests and procedures and all the adaptations that had to be implemented to overcome a number of technological and physical issues, both general and system-specific.

On the relationship between solid particle attractors and thermal inhomogeneities in vibrationally driven fluid-particle systems

“…As a natural continuation of the earlier investigation by Crewdson et al, 32 here we concentrate on a similar Prandtl number (Pr ¼ 6.1 corresponding to pure water). While the main motivation of previous studies [27][28][29][30] was a definition of the precise set of parameters for an experiment to be executed on board the International Space Station, 31 the present analysis is driven by a different need, that is, the intention to collect data for the future development of an algorithm of artificial intelligence able to determine (as an output) the thermal boundary conditions required to produce particle accumulations with a desired shape or morphology (input conditions). For this reason, here the selection of the non-dimensional parameters has not been based on the specifics of the experiment hardware available on board the International Space Station; 31 rather, such characteristic numbers have been selected in order to minimize the otherwise prohibitive computational times required by the 3D numerical simulations.…”

“…[27][28][29][30] The related properties have already been extensively described in earlier studies and have been the main subject of an experiment conducted in space. 31 For the convenience of the reader, here we limit ourselves to recalling that, from a purely mathematical point of view, such geometrical surfaces can be defined as loci of points in a threedimensional space implicitly described by a polynomial equation of degree 2. Put simply, they may be regarded as generalizations of twodimensional conic sections (ellipses, parabolas, and hyperbolas) in 3D.…”

Characterization of two-way coupled thermovibrationally driven particle attractee

“…On the other hand, conducting tests in microgravity conditions is extremely expensive. In practice (while waiting for opportunities for space experiments, Lappa et al 66 ), the most convenient way to gain an understanding of the underlying flow physics is to use numerical simulation. This explains why the existing literature on this subject relies to an unusual level on insights obtained via theoretical models and ensuing computations.…”

Supporting an ISS experiment as PhD students: a case study of the PARTICLE VIBRATION project

“…The T-PAOLA project (Thermovibrationally-driven Particle self-Assembly and Ordering mechanisms in Low grAvity, the corresponding NASA/ESA opsnom being "Particle Vibration"), however, has enabled two PhD students from the University of Strathclyde to immerse themselves in a concrete space experiment, leading to significant benefits for both the students and the project itself. In the following, first the scientific context of the experiment [1]- [4], the structure of the research team and the other stakeholders (space agencies and payload developer) are introduced. Then, the specific activities undertaken by the students to directly support the project are described, followed by a more general presentation of their respective research interests and results.…”