EMA - Engineering Marangoni Flows by Heat-Transfer Management
The handling and manipulation of liquids is a key requirement for manned and unmanned space flights. Some examples are the liquid propellant of rocket engines and the drinking water for astronauts.
If a liquid gets in contact with a gas, capillary forces act on the interface. An important effect driving a significant liquid motion is the Marangoni effect. It arises when the liquid-gas interface is locally heated or cooled. An example is the migration of oil to the colder rim of a heated pan. As the effect is independent of gravity, it is a prime driving force for fluid motion under weightlessness. The Marangoni effect is also important in crystal- growth technology for semiconductor manufacturing, since the flow induced in molten silicon has a crucial effect on the quality of the single crystal grown.
An international team consisting of scientists from Austria, Belgium, Spain and Japan is working together in the JEREMI project to manipulate and shape the Marangoni flow in the liquid by exposing the liquid bridge to an external gas stream whose strength, temperature, and chemical composition are well controlled.
Apart from gathering important information required to keep the flow laminar as long as possible, the scientists also want to unravel the reasons for a unique effect which leads to a demixing of small solid particles suspended in the liquid: after a short transient time all particles in the liquid bridge align along a wavy ribbon, which rotates about the cylindrical axis of the liquid zone.
The research within the JEREMI project will be carried out as a joint ESA/JAXA experiment on the Japanese Module KIBO utilizing the Fluid Physics Experiment Facility (FPEF) and the Image Processing Unit (IPU) onboard the International Space Station (ISS). The ESA activity is performed within the ELIPS programme.
The Austrian part (EMA) of the JEREMI project is the numerical simulation of the phenomena to predict suitable parameters for the space experiment and to analyze the phenomena theoretically. A detailed understanding of the fluid mechanics of this flow will also serve to improve industrial processes on the ground.
Vienna University of Technology - Prof. Hendrik Kuhlmann (Coordinator of the Austrian part of the project)
- Free University of Brussels, Belgium
- University of Extremadura, Spain
- Tokyo University of Science, Japan
- Yokohama National University, Japan
- Japan Aerospace Exploration Agency, Japan
Vienna University of Technology
Prof. Hendrik Kuhlmann