振动工况下船舶管道中冰晶流动特性

Flow characteristics of ice crystals in ship pipelines under vibration

极地船舶航行中,针对船舶海水冷却系统管内冰堵问题,本文基于CFD数值模拟方法,采用欧拉-欧拉双流体模型研究振动对水平直管中海水-冰晶两相流流动特性的影响,分析不同振幅、振动频率工况下水平直管内冰晶颗粒体积分布及流动压降的变化。通过实验与仿真分析,在振动频率为20 Hz条件下,直管进出口压降随振幅从0增大到1.2 mm,误差在20%范围内,确保模型的有效性。随着振动频率从0增加到50 Hz及振幅从0增大到1.2 mm,直管上壁面附近海水-冰晶颗粒体积分布逐渐减少。流速及湍流动能在近壁处均低于主流区且随振动增加而增大,而在主流区受振动影响较小。

Based on the computational fluid dynamics numerical simulation method,the Eulerian-Eulerian two-fluid model is used to study the effect of vibrations on the flow characteristics of sea-ice crystals′two-phase flow in horizontal straight pipes.The experiment and simulation analysis show that under a vibration frequency of 20 Hz,the pressure drop of the straight pipe inlet and outlet increases with the increase in amplitude from 0 to 1.2 mm,and the error is within 20%,which ensures the validity of the model.As the vibration frequency increases from 0 to 50 Hz and the amplitude increases from 0 to 1.2 mm,the volume distribution of sea-ice crystal particles near the upper wall of the straight pipe gradually decreases.The flow velocity and turbulent flow energy near the wall are both lower than those in the main flow zone and increase with increasing vibration.However,the flow velocity and turbulent kinetic energy in the main flow zone are less affected by vibration.