Stickiness of snow investigated with ice particle experiment

The way in which ice particles stick together—a process called sintering—has been a topic of interest for almost over 150 years. Since the 1800s, many studies have investigated various individual aspects of sintering, but none had considered them under one study.

Bahaloo et al. changed that with a comprehensive experiment and applied theoretical framework that describes the ice sintering force as a function of temperature, contact load, contact duration, and particle size.

“Understanding how ice particles stick together and that underlying mechanism helps us to decipher the complicated behavior of snow,” said author Hassan Bahaloo.

To investigate sintering, the authors pressed millimeter-size ice particles together before pulling them apart. By measuring the force required to pull the particles apart, the authors were able to determine the dependence of the sintering force on variables such as temperature, particle size, initial pressed force, and pressing duration.

The authors found tiny ice particles stuck together rather easily, and that the sintering force is a strong function of temperature, size, contact load, and contact duration. The experiment also showed the particles needed to be at precisely the same temperature to avoid crystals from growing on their surfaces. The results were used to create an analytic solution to predict sintering forces under different conditions.

“Snow and ice behavior, if well understood, can be used in applications like avalanche prediction and prevention, snow-accumulation prevention for autonomous cars, wind turbine de-icing, and more,” Bahaloo said.

In the future, the researchers plan to extend the study to include shear forces and other variables like surface roughness, which will be used to improve a snow behavior computer model.

Source: “Ice sintering: Dependence of sintering force on temperature, load, duration, and particle size,” by Hassan Bahaloo, Tobias Eidevåg, Per Gren, Johan Casselgren, Fredrik Forsberg, Per Abrahamsson, and Mikael Sjödahl, Journal of Applied Physics (2022). The article can be accessed at https://doi.org/10.1063/5.0073824 .