ABSTRACT
After the opening of the new Arctic channel, more and more ships are carrying goods through the Arctic channel. Under polar conditions, the crystallization of sea water affects the normal running of ships. This paper discusses the effects of fluid flow on sea ice crystallization from the perspective of heat-mass transfer, phase change and hydrodynamics. A microscopic mathematic model for sea ice crystallization is established based on phase-field method and lattice Boltzmann method. The two-dimensional simulation is conducted, in which the Phase field, salt-concentration field, temperature field and flow field was coupled. The sea ice crystal growth under natural convection and external forced convection is studied. The results show that the flow of seawater changes the concentration of seawater around the sea ice, and different concentrations of seawater cause different crystallization rates. The flow also changes the heat-mass transfer, which reduces the degree of subcooling. Both affect the shape and structure of sea ice crystallization.
In 2009, the German shipping company crossed the Arctic along the northern coast of the Eurasian landmass for the first time, marking the opening of the Arctic Northeast Passage. The channel has a large amount of resource reserves, good navigation conditions and an important strategic position, which makes it quickly the focus of attention of all countries. When the ship is traveling in the Arctic ice zone, the water inlet pipe of the ship is extremely susceptible to freezing at low temperatures, and the continuous accumulation of sea ice gradually blocks the cooling pipe, resulting in the ship's cooling system not working properly and prone to safety accidents. Since the seawater is always in a flowing state relative to the ship's pipeline during the travel, it is necessary to study the crystallization characteristics under the seawater flowing state. At present, most of the research methods for frozen crystallization of seawater are based on the classic crystal nucleation theory from a macro perspective, using statistical methods to investigate the process of seawater crystal growth. This method can predict the growth process of ice crystals and can be verified by setting up a seawater desalination test bench, but it cannot systematically explore the heat and mass exchange during the crystallization process.
