Cavitation-induced nucleation of zirconium in low earth orbit

Liquid-to-solid nucleation experiments on pure zirconium were performed onb oard Spacelab. No evidence for fluid flow effects on nucleation was found f or maximum flows from 5 to 43 cm s(-1). Evidence for fluid flow effects on nucleation was found at flow velocities above 50 cm s(-1). At this flow vel ocity and above, the dynamic pressure in the drop exceeds the static pressu re, a condition that is known to provide a driving force for cavitation in fluids. Under these conditions undercooling was severely limited. (C) 1999 American Institute of Physics. [S0003-6951(99)00318-6].