Microgravity offers a unique perspective on fluid physics with broad potential Earth applications in such varied areas as energy, agriculture, and manufacturing.
Phase transitions of colloids are easier to observe in microgravity. Foams, which are particularly sensitive to gravity, are more stable in microgravity. In magneto-rheological fluids in 1g, the magnetic particles often fall out of suspension due to sedimentation, but in microgravity this does not occur. Investigations of the behavior of granular systems are likewise more feasible in microgravity. Microgravity can also be used to better understand processes such as boiling, steam condensation, and diffusive transport.
Microgravity provides an opportunity to better understand interfacial phenomena, such as the wetting and spreading of immiscible liquids or the spreading of fluid across a solid surface. In reduced gravity, wetting determines the configuration and location of fluid interfaces, thus greatly influencing, if not dominating, the behavior of multiphase fluid systems. Microgravity also allows unique investigation of surface tension forces that are masked in 1g, as well as drop dynamics, capillarity, and magneto/electro-hydrodynamics.