Phase-field Simulation Of Ice Crystal Growth Of Polar Ship Seawater Cooling System And Flow Characteristics Study Of Ice Slurry In The Pipe

With the increasing change of global climate,the melting process of Arctic sea ice is accelerating.Especially in recent years,the ice-free period occurred in some waters of the Arctic at every summer.There have been many merchant ships successfully get through the arctic route.In the near future “ice-free arctic route” is likely to become a reality.When the ship sailing in the extreme cold environment,very low temperatures will cause ice crystals grow up and in the process of flowing in the seawater pipeline may also lead to the accumulation of ice.These factors may cause paralysis of the ship seawater cooling system,so that the temperature of ship cooling water system is too high,causing the marine power system cannot run normally.Therefore,the research is carried out in this paper about phase field simulation of sea ice crystal growth process and the flow characteristics of ice slurry in the pipe.In view of growth evolution problem of sea ice crystals,the phase field model of sea ice crystal is established based on Ginzburg-Landau theory.In order to obtain a more realistic appearance of ice crystals,anisotropy and thermal disturbance are introduced into phase field model.Finite difference method is used for the discrete processing of phase field model,the calculation process of phase field model through programming.Tecplot is used for after-treatment of calculation results,analyzing the results of the phase field simulation of sea ice.Many research results obtained by study.With the increase of space step,distortion situation of morphology of ice crystals is more and more serious.In order to ensure the accuracy of phase field simulation of sea ice crystals,in the process of simulation the space step select 0.4 ?.With the migration of time,sea ice crystal is growing up,its appearance is a regular hexagon shape.The change trend of tip growth speed is firstly reduce and then gentle,and the change trend of tip temperature is firstly increase and then gentle.Undercooling has a greater effect on the growth of ice crystal,in the case of larger undercooling the growth of ice crystals speed is faster,and the secondary dendrite of ice crystals is more developed.Anisotropy has a greater effect on the ice crystal growth,in the case of larger anisotropy the growth of ice crystals speed is faster,and if the degree of anisotropy is too large may cause structure distortion of ice crystal.Thermal perturbation makes the secondary dendrite of sea ice crystals become more developed.It has a greater effect on the growth speed of sea ice crystals,and if disturbance is too large,the morphology of the sea ice crystal is easy to distortion.In view of the flow characteristics of ice slurry in the pipe,double fluid Euler model in Fluent are adopted to simulate flow characteristics of ice slurry in the horizontal straight and 90 ° elbow.The distribution of ice crystal particles flowing in the horizontal straight and 90 ° elbow are analyzed.The influence of flow rate,pipe diameter,ice crystal grain size and concentration to ice slurry two-phase flow is obtained.