Abstract
Ice accretion is a hazard for offshore operations on cold northern waters. Icing on vessel surfaces can be caused by a variety of phenomena, including cold air temperature, low water temperature, freezing rain, and supercooled fog, among others. A single salt water droplet's phase change behaviour after impacting on a very cold surface is numerically studied in this paper. The model used in this study solves the flow equation, composed of energy balance and the volume fraction equations. The new predictive techniques developed in this research provides important new insights on sea spray icing of arctic vessels, medium-sized fishing trawlers, and offshore structures operating in harsh offshore environments. The main objective of the study is to investigate the influence of several physical properties on droplet freezing. Important factors include liquid fraction, salinity effect, total freezing time, and rate of total heat transfer. The liquid fraction helps to understand the complete phase change behaviors by means of three distinct transition stages: fully liquid stage, mushy or transition stage, and complete ice phase. The simulated results based on salt water properties show salinity increases total freezing times. Wall heat transfer and temperature distribution help to show heat transfer rates between the droplet and object surface. Further, this research provides an important technical achievement for ice load prediction, modeling and preventation. This contribution is particularly significant for vessels and offshore petroleum industries in the Northern environment.
