Wind tunnel experiment and thermodynamic modeling for dry-snow accretion on a heated surface

Abstract

Wind tunnel experiments and modeling of dry-snow accretion on a heated surface were performed to estimate the characteristics of dry-snow accretion occurring in sub-freezing temperatures by using cold-climate facilities. The experiments encompassed a wide range of meteorological conditions—air temperature, wind speed, and snow flux—and were conducted over a surface heat flux range of 300–1800 W/m2. The measurements were performed with respect to the snow properties, including growth rate, sticking efficiency, and liquid water content (LWC), and were used to analyze the impact of dry-snow accretion on a heated surface. The experimental results demonstrated the distinct influence of the surface heat flux on the snow accretion process. The sticking efficiency was found to highly correlate with the LWC of the accreted snow and meteorological parameters, and the accreted snow layer was shed from the surfaces when the LWC was slightly above 40%. Moreover, on the basis of heat and mass transfer during the accretion process, models for estimating sticking efficiency and LWC were developed for dry-snow accretion on a heated surface. The effects of convective cooling and evaporation of liquid water inside the accreted snow were incorporated, and the models were cross-validated with the experimental results. The equation was applied to the determination of the minimum value for sticking efficiency, and a linear proportional relation between sticking efficiency and meteorological parameters was demonstrated.