CLASSICAL AND QUANTUM TURBULENCE IN CRYOGENIC F'LUIDS S ettore soientifico-dis ciplinare

Two different projects on the characterization of classical and quan-tum turbulent flows using frozen particles and cryogenic fluids are reported. The first project presents the benefits and drawbacks of using liq-uid nitrogen for fluid dynamics experiments compared to other test fluids. This study is focused on the visualization of high-Reynolds number flow, and presents a new technique that utilizes frozen par-ticles as tracers. The technique would provide a cheap and easy way to produce tracers for visualization in liquid nitrogen, using common hydrocarbons or even atmospheric air. The technique has been proved viable experimentally, producing micron-sized particles when atmospheric air is injected, and particles as small as 500nm in diameter with a mixture of nitrogen gas and methane as the seeding gas. These particles have been successfully used as tracer