摘要
利用VOF(volume of fluid)方法和realizable湍流模型对中空离心式喷嘴的气液两相流动进行了数值模拟,并将模拟结果与实验数据进行了对比,两者结果吻合良好。模拟结果表明:旋流室内压力随半径的减小而减小;在中心1/3半径范围内存在低压区,其存在将会引起喷口外部空气抽吸,形成空气心,空气心半径越大,液膜越薄,在大于1/3半径区域内有较高的动压,将引起液膜在该区域扩展喷淋。喷嘴出口处液相体积分数为1,离喷口距离越远,液相体积分数越小;出口速度随入口压力的增大而增大,出口速度的方向以及喷嘴内流体迹线图表明了液体是旋转流出喷嘴的。
By making use of the VOF(volume of fluid) method and realizable k-ε turbulent flow model,the authors conducted a numerical simulation of the gas-liquid two-phase flow in a hollow centrifugal type nozzle and compared the simulation results with the test data.Both were in good agreement.The simulation results show that the pressure inside the swirling flow chamber will decrease with a decrease of its radius and a low pressure zone exists in a range of 1/3 of the radius around the center.The existence of such a low pressure zone will result in suction to the air outside the nozzle,forming an air core.The bigger the radius of the air core,the thinner the liquid film.There exists a relatively high dynamic pressure in the area greater than 1/3 of the radius.This will cause the liquid film to extend its sprinkling in the area.If the liquid phase volumetric fraction at the outlet of the nozzle equals to 1,the more remote from the nozzle,the smaller the liquid phase volumetric fraction.The outlet speed will increase with an increase of the inlet pressure.The direction of the outlet speed and the fluid trajectory chart inside the nozzle show that the fluid flows out of the nozzle in a rotating state.
出处
《热能动力工程》
CAS
CSCD
北大核心
2011年第5期599-603,636,共5页
Journal of Engineering for Thermal Energy and Power
关键词
VOF
离心式喷嘴
两相流
压强分布
空气心
速度流场
VOF(volume of fluid),centrifugal type nozzle,two-phase flow,pressure distribution,air core,velocity flow field
