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Miscible Fluids in Microgravity (MFMG)
01.27.10

Overview | Description | Applications | Operations | Results | Publications | Images

Experiment/Payload Overview

Brief Summary

This experiment will demonstrate the existence of tension-induced convection in miscible (mixable) fluids. This work will help researchers and manufacturers understand miscible polymer processing in microgravity and on Earth.

Principal Investigator

  • John Pojman, Ph.D., University of Southern Mississippi, Hattiesburg, MS

    • Co-Investigator(s)/Collaborator(s)

  • Vitaly Volpert, Ph.D., Universite Lyon I, Villeurbanne, France
  • Nicholas Bessonov, Ph.D., Institute of the Problems of Mechanical Engineering, St.Petersburg, Russia

    • Payload Developer

    Marshall Space Flight Center, Huntsville, AL

    Sponsoring Agency

    National Aeronautics and Space Administration (NASA)

    Expeditions Assigned

    |8|9|10|11|

    Previous ISS Missions

    A related experiment was flown 4 times on a KC-135 aircraft.

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    Experiment/Payload Description

    Research Summary

    • The goal of the Miscible Fluids in Microgravity (MFMG) experiment is to test the fluid dynamics between two miscible (or mixable) liquids in a microgravity environment provided by the International Space Station.


    • The interaction between two miscible liquids here on Earth would be masked by the effects of either gravity or density, and in effect, the two miscible liquids would combine into one relatively homogenous (or equally distributed) solution.


    • In microgravity, miscible liquids may behave completely differently, potentially taking on properties more akin to immiscible (or non-mixable) liquids. The MFMG experiment will study these interactions.

    Description

    The goal of the Miscible Fluids in Microgravity (MFMG) experiment is to test the fluid dynamics between two miscible (or mixable) liquids in a microgravity environment provided by ISS. Earth?based applications of this work may help researchers better understand processing of miscible polymers.

    This experiment was designed to demonstrate the existence of surface tension-induced convection in miscible fluids. The effects of surface tension on the interaction between two miscible liquids here on Earth are masked by the effects of gravity and density. On Earth, miscible liquids effectively combine into one relatively homogenous (or equally distributed) solution. In microgravity, miscible liquids may behave completely differently, potentially taking on properties more akin to immiscible (or non-mixable) liquids. The role of interfacial surface tension in miscible liquids was proposed by the Dutch mathematician Korteweg over 100 years ago. Testing Korteweg?s hypothesis is challenging on Earth because the force of gravity overwhelms surface tension, but the microgravity environment on station provides an ideal opportunity to do so.

    This experiment originated from a call for simple experiments requiring little upmass following the grounding of the space shuttle fleet after the loss of Columbia. The MFMG experiment was proposed as a simple study of miscible fluids limited to the use of ordinary items already on board ISS (unused syringes, water, honey, Ziploc bags, a still camera, and a video camera). In the isothermal experiment (where diffusive forces predominate in microgravity), a stream of either honey or water was introduced into a syringe of the opposite fluid to observe the transient behavior of the miscible fluids. In the thermal experiment, a temperature gradient was created across the syringe holding one of the fluids, and a second fluid was introduced at ambient temperature.

    Korteweg?s theory predicts that miscible fluids will demonstrate interfacial tension transiently until diffusion prevails. Under normal gravity, the stream of honey would break apart under its own weight and surface tension would cause the fluid to have as little surface area as possible for a given volume. The droplets that form as the stream breaks apart would have less surface area than a cylinder (stream) of the same volume?an effect known as Rayleigh instability. The experiment will determine whether the stream exhibits the Rayleigh instability characteristic of immiscible fluids.

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    Applications

    Space Applications

    The study of fluid dynamics and the interface between two miscible (or mixable) fluids is an experiment that has not been conducted in microgravity before. From a commercial aspect, the most significant contribution of this project will be the potential manufacture of synthetics, polymers, and medicines in space.

    Earth Applications

    One hundred years ago, a scientist named Korteweg predicted that miscible fluids could act like immiscible fluids until they had diffused and become uniform. Although there has been much theory and some provocative experiments during the intervening century, no definitive experiments have been performed because the force of gravity overwhelms surface tension. The microgravity environment in the ISS provides an ideal opportunity to test Korteweg's hypothesis.

    Although the phenomena in the MFMG experiment can only be observed in weightlessness, there are 'down to earth' implications of the results. The models used to simulate the experiment provide information on the fundamental interactions between molecules, and the results of the experiment could help develop improved understanding of processes in the plastics industry, where miscible fluids are used, and in medical research, such as protein crystal growth in microgravity.

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    Operations

    Operational Requirements

    MFMG must be conducted under quiescent conditions so that random vibrations do not interfere with the results of the study. This experiment requires video.

    Operational Protocols

    MFMG uses simple supplies: a container of water (at least 20 milliliters, or 0.68 fluid ounces), a container of glycerin (or a concentrated sugar-water, honey-water, or salt-water solution), water soluble dye, and a syringe for injecting the fluids. The video taped results will be downlinked.

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    Results/More Information



    Isothermal results: Four sessions were performed with no observation of Korteweg?s prediction of the Rayleigh instability. It was found that the honey did not break into small drops, neither did it change its shape when injected. The behavior that was exhibited was that of simple diffusion, which is seen on Earth when mixing two miscible fluids.

    Thermal results: Two sessions of MFMG were performed with a thermal gradient introduced. The stream migrated towards the warmer side of the temperature gradient, which may indicate the presence of Korteweg?s predicted behavior. Further sessions with thermal gradients are still being analyzed.

    Despite the negative results ? the authors concluded that the surface tension stesses were insufficient to overcome the large difference in viscosity of the honey-water system ? the data were used to calculate the square gradient parameter for the water-honey system. (Evans et al. 2009)

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    Related Web Sites
  • Science @ NASA
  • NASA Fact Sheet
  • Science @ NASA: Space Station Ingenuity
  • Pojman Research Group
  • Life of D.J. Korteweg

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    Publications

    Results Publications
    • Pojman JA, Bessonov N, Volpert V. Miscible Fluids in Microgravity (MFMG): A Zero-Upmass Investigation on the International Space Station. Microgravity Science and Technology. 2007 ;XIX: 33 - 41.
    • Pojman JA. Miscible Fluids in Microgravity (MFMG): A Zero-Upmass Experiment on the International Space Station. Proceedings of the 43rd AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV. Jan 10 - 13, 2005 ;AIAA 2005-718.

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    Related Publications
    • Volpert VA, Pojman JA, Texier-Picard R. Convection induced by composition gradients in miscible systems. C.R. Mecanique. ;330:1-6 [French]. 2002.
    • Pojman JA, Whitmore C, Liveri MLT, Lombardo R, Marszalek J, Parker R, Zoltowski B. Evidence for the Existence of an Effective Interfacial Tension Between Miscible Fluids: Isobutyric Acid - Water and 1-Butanol - Water in a Spinning-Drop Tensiometer. Langmuir, American Chemical Society. ;22:2569 - 2577. 2006
    • Bessonov N, Volpert V, Pojman JA, Zoltowski BD. Numerical Simulations of Convection Induced by Korteweg Streses in Miscible Polymer-Monomer Systems. Microgravity Science Technology. ; 17 (1). 2005
    • Bessonov N, Pojman JA, Volpert V. Modelling of Diffuse Interfaces with Temperature Gradients. Journal of Engineering Mathematics. ;49:321-338. 2004
    • Volpert VA, Pojman JA, Texier-Picard R. Convection Induced by Composition Gradients in Miscible Systems. Comptes rendus de l'Academie des sciences Mecanique. ;330:353-358. 2002
    • Bessonov N, Pojman JA, Volpert V. Miscible Fluids in Microgravity (MFMG). Proceedings of the 42nd AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV. Jan 5 - 8, ;AIAA-2004-962. 2004

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    Images

    imageNASA Image: ISS008E18752 - Honey injected into water during the MFMG experiment onboard the International Space Station, March 2003.
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    imageProfessor Pojman displays the prototype MFMG experiment. Image courtesy NASA.
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    imageNASA Image - ISS010E22747 MFMG syringe containing a honey and water mixture on ISS Expedition 10.
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    imageNASA Image: ISS011E07709 - ISS Expedition 11 Science Officer, John Phillips, setting up the MFMG hardware before the final session of MFMG. At the work table, Phillips slowly injected tinted water into honey for MFMG.
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    imageNASA Image: ISS011E07771 - Close up view of the MFMG syringe containing honey injected with tinted water during Expedition 11.
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    Information Provided and Updated by the ISS Program Scientist's Office
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