The phenomenon of supercooling crystallization exists in many fluids. Actively triggering nucleation to release supercooling is critically important in many fields, such as phase-change thermal energy storage, dynamic ice making via supercooling, crystallization and so on. The advantage of mechanical nucleation triggering lies in not adding other substances, low energy consumption, and high efficiency. However, how mechanical disturbance affects nucleation and the main influencing parameters have long remained unclear. This paper systematically conducted experimental research on mechanical impact in supercooled water to induce nucleation, primarily investigating the influence patterns of different parameters on nucleation and their relationship with the degree of supercooling. The results show that the material of the impact components directly affects nucleation triggering efficiency, for example, aluminum being greater than acrylic. Hammer mass, impact energy, and impact acceleration show no significant correlation with nucleation temperature. A parameter SN related to nucleation induced by mechanical impact was proposed, which consists of the hammer's free fall height h and the impact contact size Dc. An empirical relationship between the pre-nucleation supercooling ΔT and SN was established. The research results and findings of this paper reveal the correlation between mechanical impact and triggering nucleation, deepen the understanding of nucleation induced by mechanical disturbance, and simultaneously contribute to the development of mechanically nucleation triggering technology.
Wang et al. (Sun,) studied this question.