摘要
为了获得剪切型空化喷嘴空化水射流流场的流动特性,利用FLUENT软件对射流全流场进行数值模拟。多相流动模型选择混合模型,空化模式由混合密度函数和蒸汽输送方程组成,分析喷嘴入口压力对射流流场的轴向速度、轴向动压强及气相体积分数分布特性的影响。结果表明,不同压力条件下射流轴向速度和轴向动压强分布规律相同,且具有显著的轴对称性。喷嘴发生空化时气泡最先发生在射流由圆柱段进入扩散段的位置,当压力为20 MPa时,在靶距约为17 mm的外流场区域出现涡环,且随着压力的增加,外流场靠近喷嘴扩散段位置的气相体积分数和最大气相体积分数不断增大;当压力增加到45 MPa时,喷嘴扩散段与外流场的涡环相连形成一条气相通道,该气相通道的直径随着压力的增加而增大。
This paper introduces a study seeking to identify the flow characteristics behind the cavitation water jet flow field of the shear cavitation nozzle. The research involves simulating the entire flow field of the jet using FLUENT software; and analyzing the distribution law underlying the axial velocity, axial dynamic pressure and gas phase volume of the internal outflow field under different inlet pressure conditions by selecting the mixing model for the multiphase flow model in the process of numerical simulation and using the cavitation model consisting of the mixing density function and the steam transport equation. The results demonstrate that the same distribution law underlies axial velocity and axial dynamic pressure under different pressure conditions, suggesting remarkable axial symmetry;when the nozzle cavitation takes place, the bubble first appears in the position where the jet enters the diffusion section from the cylinder section ; when the pressure is 20 MPa, the vortex ring appears in the area of the outer flow field with a target distance of about 17 mm; along with the increase of pressure comes a constant increase in the value of the gas volume fraction and the max value of the gas volume fraction in the external flow field near the nozzle diffusion section; and when the pressure rises to 45 MPa, the nozzle diffuser section is connected with the vortex ring of the outflow field to form a vapor phase channel which increases in diameter with the increase of pressure.
作者
董星
李金林
李哲
靳晓明
Dong Xing;Li Jinlin;Li Zhe;Jin Xiaoming(School of Mechanical Engineering,Heilongjiang University of Science ＆ Technology,Harbin 150022,China;School of Environmental ＆ Chemical Engineering,Heilongjiang University of Science ＆ Technology,Harbin 150022,China;Center of Engineering Training ＆ Basic Experimentation,Heilongjiang University of Science ＆ Technology,Harbin 150022,China)
出处
《黑龙江科技大学学报》
CAS
2018年第5期560-565,共6页
Journal of Heilongjiang University of Science And Technology
基金
黑龙江省自然科学基金项目(E2016060)
黑龙江省教育厅科学技术研究项目(12531569)
关键词
水射流
空化
喷嘴
流场
数值模拟
water jet
cavitation
nozzle
flow field
numerical simulation
