Falling Objects in Non-Viscous Fluids

Optical cryostat technology allows an experimentalist a high-degree of access to probe and observe low-te perature liquid-helium. Using a helium 4 evaporative cooler, the temperature of helium can be dropped to around 1k. At these temperatures, the superfluid fraction is very nearly one and the motion of the fluid is well-described by Euler's equation. A standard textbook problem with non-viscous fluid is the motion of a sphere or airfoil moving at constant velocity. The work will test these models, presenting video measurements of free-falling solid macroscopic objects dropped into superfluid and normal fluid.