Fluid Science Laboratory (FSL)
FSL is a multi-user facility for conducting fluid physics research in microgravity conditions. It is operated in fully- or in semi-automatic mode and can be controlled by the ISS astronauts, or from the ground in the so-called telescience mode.
The main objective of performing fluid science experiments in space is to study dynamic phenomena in the absence of gravitational forces. Under microgravity, such forces are almost entirely eliminated thereby significantly reducing gravity-driven convection, sedimentation and stratification and fluid static pressure, allowing the study of fluid dynamic effects normally masked by gravity. These effects include diffusion-controlled heat and mass transfer.
The absence of gravity-driven convection eliminates the negative effects of density gradients (inhomogeneous mass distribution) that arise in processes involving heat treatment, phase transitions, diffusive transport or chemical reaction. Convection in terrestrial processes is a strong perturbing factor, the effects of which are seldom predictable with great accuracy and which dominate heat and mass transfer in fluids.
The ability to accurately control such processes remains limited, and their full understanding requires further fundamental research by conducting well-defined model experiments for developing and testing related theories under microgravity. This should facilitate the optimisation of manufacturing processes here on Earth and improve the quality of high value products, such as semiconductors. The Fluid Science Laboratory facility builds upon the experience gained by Europe through the Bubble, Drop and Particle Unit facility that flew on several Spacelab missions.
Experiments are integrated in an FSL Experiment Container (EC). With a typical mass of 25-30 kg (max. 40), and standard dimensions of 400x270x280 mm3, the EC provides ample space to accommodate the fluid cell assembly, including any necessary process stimuli and dedicated electronics.
A very complete set of optical diagnostic instruments is integrated within FSL. It allows:
Visual observation along two perpendicular axes, with direct registration via internal B/W digital cameras, and with additional capabilities provided by external Front Mounted Cameras (FMC’s), offering high-speed, high-resolution, infrared, and colour recording;
Background, volume, and travelling light sheet illumination with either white or monochromatic light sources;
Particle image velocimetry, including imaging of liquid crystal tracers for simultaneous velocity and temperature mapping;
Thermographic mapping of free liquid surfaces, using the infrared FMC
- Interferometric observation along two perpendicular axes utilising a combination of state-of-the-art convertible interferometers with active alignment capabilities:
- Digital holographic interferometer;
- Wollaston/shearing interferometer;
- Schlieren observation mode;
- Elecronic Speckle Pattern Interferometer (ESPI).
More information about the FSL experiment containers is linked from the righthand menu.
Last update: 13 May 2009