Samantha Science: Fluids - Astronauts News

It is very difficult to predict the behavior of fluids on Earth; In space, without the effect of gravity, it’s more than that.

For an astronaut, getting the last drop of orange juice out of his can be a frustrating experience. In parallel and to varying degrees of sophistication, engineers who design satellites so that they can use every last drop of thrust in weightless conditions or who design rockets with tanks capable of sending fuel to thrusters under extreme load conditions and efficiently, face difficult engineering challenges.

Fluid mechanics experiment fluid (Floyd Dynamics in Space) investigates the phenomenon mentioned flow (Translatable in Italian twisting, i.e. the agitation of the liquid upon vibrating a closed container) when it occurs under the conditions found on the International Space Station, or in microgravity. This is the subject of the first part of the experiment.

European Space Agency astronaut Thopmas Pesquet shortly before installing the FLUIDICS experiment in the Columbus Laboratory unit. Credits: ESA/NASA

To do this, the FLUIDICS device simulates the motions of a satellite in space, using a centrifuge that moves a transparent ball filled with a colored liquid. In this case, the goal is to understand how best to improve satellite maneuvers in order to extend their operational life in relation to the availability of propellant.

The second part of the experiment concerns the analysis, at the most basic level, of the energy transfer processes that occur on the surface of the moving fluid. These phenomena are called wave disturbance (wave disturbance in Italian) and is still little known in the scientific community. Gravity and surface tension on Earth affect how force is dissipated in waves or surface ripples. Using data from FLUIDICS, scientists can observe how surface forces behave in conditions of weightlessness, thus removing the influencing factor (gravity), to simplify understanding of the phenomenon. This will not only be useful for engineers designing space systems, but will also serve to develop better climate models and more accurately predict the state of the seas, for example in order to take advantage of the generation of electricity from sea surface waves.

Thomas Bisquet during the installation phases of the FLUIDICS experience. Credits: ESA/NASA

More specifically, by wave turbulence we mean all those irregular movements of a liquid’s surface, like sea waves. Although many theoretical approaches have been applied on this topic for more than 40 years, the phenomenon of wave turbulence is unfortunately not an area of research of particular interest to scientists. Fluidics will allow researchers fromOrdinary High School Paris and National Center for Scientific Research To fully understand this topic.

The goal of this experiment is to validate predictions of fluid behavior under microgravity conditions. The first part of the experiment looks at technological issues related to fluid damage during satellite maneuvers. The second part will allow the observation of capillary wave turbulence at the surface of the fluid layer, in a low-gravity environment.

FLUIDICS EXPERIENCE DIAGRAMS. Credits: ESA

the team

FLUIDICS is run by researchers from the French space agency CNES andAcademy of Sciences French, developed by CNES and sponsored by the European Space Agency, CNES and Airbus DS. Its operational period on the station extends from November 2016, when it was installed by French astronaut Thomas Bisquet in the Columbus module, during the Proxima mission, to March 2023.

Applications

In terms of space technologies, the results of FLUIDICS can aid the development of projects with better optimization of fuel management systems and can provide solutions to increase the useful life of a satellite, through better management of propellant for maneuvers.

On Earth, the results of this experiment, in addition to helping to understand the motions of fluids, are useful for a better understanding of the behavior of our planet’s oceans, including the phenomenon of anomalous waves. Overall, the expected results from the experiment can help improve climate prediction systems and improve the use of renewable energy from the oceans.

a description

The FLUIDICS devices consist of three small transparent balls, with a centrifuge for moving liquid inside and two dedicated cameras. The first ball, used to analyze wave disturbances, contained colored distilled water. The other two balls, which are used for research, contain a special liquid with low viscosity and low surface tension. The obtained results were analyzed and compared with simulation models. The duration of a few minutes from each session of the experiment allows observation of phenomena that have never been observed either on Earth or during parabolic flights. Over the course of the other mission increase, three more orbs were added to collect more data.

One of the transparent areas of the FLUIDICS experiment aboard the International Space Station. By analyzing the behavior of the fluid present in this field, the position of the center of mass with respect to the temperature gradient is studied, simulating what is happening in the fuel tank in space. Observing the capillary turbulence at the surface of the fluid bed in a low-gravity environment can help determine precisely the amount of fluid present in the sphere. Credits: ESA/NASA

Fluidics with one of the three subject areas of the experiment. Credits: CNES

Crew operation

NASA astronaut Victor Glover reinstalled the FLUIDICS experiment in February 2021. Credits: ESA/NASA

The first session requires 3 hours of crew time to assemble, prepare, implement and finish the experiments. In addition to managing individual sessions for the various tests, the crew will have to make a copy of the video related to the individual test, which must be watched before being able to move on to the next test. The duration of one test is approximately 5 minutes.

data management

Regardless of the purely operational and technical aspects, it must be said that during the test sequence, the movement of the fluid generated by the rotation of the centrifuge is recorded by two video cameras placed at two different observation points of the sphere. Videos and recordings of in-play forces detected by special sensors are downloaded at the end of each test session.

System data is used to characterize micro-vibrations located near the device SAMS (space accelerometer system) to the International Space Station. The SAMS measures vibrations and turbulence from transient accelerations caused by station activities such as the operation of various on-board subsystems, experiment operations, contractions and thermal expansion of orbital site structures and crew movements. When needed, sensor systems 3-axis remote sensor The SAMS system (RTS) is used to monitor the acceleration generated by the International Space Station, for each individual experiment that requires this type of detection. The SAMS module in the Columbus Laboratory module is available to support FLUIDICS and therefore no transfer or different settings of its sensors are necessary.