unterkühlter

Unterkühlter is a German term that translates to "supercooled" in English. It refers to a state in which a liquid is cooled below its freezing point without becoming solid. This occurs when the liquid is kept free from nucleation sites, which are surfaces or impurities that can initiate the formation of crystals.

Supercooled liquids are in a metastable state, meaning they are not in their most stable form. The introduction of a nucleation site, such as a tiny crystal or even a sharp jolt, can trigger rapid solidification. This phenomenon is observed in various substances, including water, but also in other liquids and even gases.

In meteorology, supercooled water droplets are a common occurrence in clouds at temperatures below freezing. When these droplets come into contact with an aircraft, they can freeze on impact, forming ice, which can be hazardous to flight. This is a primary concern for aviation safety, and de-icing procedures are designed to prevent or remove such ice accumulation.

The process of supercooling is also relevant in industrial applications and scientific research, such as in the study of phase transitions and the development of new materials. Understanding the conditions under which supercooling occurs and how to control it is important for various technological advancements.