Relationships between Surface Properties and Snow Adhesion and Its Shedding Mechanisms

Abstract

Understanding the mechanisms of snow adhesion to surfaces and its subsequent shedding provides means to search for active and passive methods to mitigate the issues caused by snow accumulation on surfaces. Here, a novel setup is presented to measure the adhesion strength of snow to various surfaces without altering its properties (i.e., liquid water content (LWC) and/or density) during the measurements and to study snow shedding mechanisms. In this setup, a sensor is utilized to ensure constant temperature and liquid water content of snow on test substrates, unlike inclined or centrifugal snow adhesion testing. A snow gun consisting of an internal mixing chamber and ball valves for adjusting air and water flow is designed to form snow with controlled LWC inside a walk-in freezing room with controlled temperatures. We report that snow adheres to surfaces strongly when the LWC is around 20%. We also show that on smooth (i.e., RMS roughness of less than 7.17 μm) and very rough (i.e., RMS roughness of greater than 308.33 μm) surfaces, snow experiences minimal contact with the surface, resulting in low adhesion strength of snow. At the intermediate surface roughness (i.e., RMS of 50 μm with a surface temperature of 0 °C, the contact area between the snow and the surface increases, leading to increased adhesion strength of snow to the substrate. It is also found that an increase in the polar surface energy significantly increases the adhesion strength of wet snow while adhesion strength decreases with an increase in dispersive surface energy. Finally, we show that during shedding, snow experiences complete sliding, compression, or a combination of the two behaviors depending on surface temperature and LWC of the snow. The results of this study suggest pathways for designing surfaces that might reduce snow adhesion strength and facilitate its shedding.

Effects of Solid Precipitation and Surface Corrosion on the Adhesion Strengths of Sintered Hydrate Deposits on Pipe Walls

“…45 Similar phenomenon was also reported in Sojoudi et al's work, in which they suggested that extreme rough surfaces would lead to small contact area between snow and surface, resulting in low snow adhesion strength. 46 Effects of Quartz Sand. Sand production is a large issue for unconsolidated sandstone reservoirs, especially for natural gas hydrate reservoirs.…”

“…In fact, the adhesions of numerous solid precipitations (e.g., ice, snow, and scale) are the function of substrates surface property. 34,46,48 Recently, Sojoudi et al and Smith et al reported a strong linear relationship between the adhesion strength of the THF/CyC5 hydrate and the practical work of adhesion between a droplet and the underlying substrate. 20,49 Herein, the measured sintered hydrate deposit adhesion strength under different conditions, τ h , versus the calculated work of adhesion for a droplet was plotted in Figure 7(a).…”

Facilitating Large‐Scale Snow Shedding from In‐Field Solar Arrays using Icephobic Surfaces with Low‐Interfacial Toughness

“…Note that Γ and values are likely to be different between snow and ice, due to the difference in the physical/mechanical properties between them. [ 4 ] For example, the modulus of snow can vary from ≈100 kPa to 8 GPa (that of bulk ice).…”

Active prevention of snow accumulation on cameras of autonomous vehicles

“…Here, snow was generated using a snow gun operating inside a walk-in cold room that could reach temperatures up to − 20 °C [41]. Water and compressed air Fig.…”

“…The LWC of snow grains is an important parameter that affects the interfacial forces during the impact. It has been proved that snow has its maximum cohesion and adhesion strengths at LWC values of ≈ 20%, and consequently stick strongly to surfaces [40,41]. Due to weak stickiness of dry snow grains (LWC < 5%) to surfaces, snow accumulation at sub-freezing temperatures is limited to low wind velocities [27].…”