Scaling law for salty sea spray icing wind tunnel test

When ships navigate in polar regions, a large amount of low-temperature salt-containing spray exists in the air. Long-term exposure to the spray can cause the upper structure of the vessel and the internal intake of gas turbines to freeze, affecting the normal navigation of the ship. Large-scale icing wind tunnels can simulate the ice accretion of sea spray on ship components or scaled models, but the corrosive effect of seawater spray can endanger equipment’s safety. Therefore, sea spray icing experiments were conducted on small-scale equipment. The study of scaling law was conducted in a wind tunnel to simulate the icing of salinity sea spray. Physical properties were tested on various components of seawater samples, obtaining the surface tension, thermal conductivity, specific heat capacity, phase transition temperature, and latent heat. On the basis of classical similarity theory, the main differences between the icing of sea spray and pure water were analyzed. The classical icing wind tunnel scaling law was adopted and modified with the extension of the water film similarity and sea spray freezing coefficient. Ultimately, a scaling parameter equation for salinity sea spray icing was established, along with a corresponding process for scaling transformation. The icing condition of the NACA0012 model under sea spray conditions was scaled with the established scaling law, and the NNW-ICE software is used to validate the scaling law. The results indicate that via establishing the scaling law, it is possible to simulate the ice shape of salinity sea spray using pure water in icing wind tunnel tests. This study provides significant theoretical support for large-scale icing wind tunnels to conduct sea spray icing tests. © 2023 Chinese Society of Astronautics. All rights reserved.