摘要
为了研究离心泵空化时内部流动机理,应用Fluent软件中的RNGK-ε湍流模型和壁面函数法,对1个比转数为47的离心泵在不同工况下其内部定常三维湍流空化流场进行数值模拟,分析了不同工况下叶轮中间流面和叶片中间流线的静压分布、速度分布及空泡体积分数分布的变化规律。结果表明:低压区位于叶片吸力面进口稍后处,此处正是空化初生的位置;叶轮进口处存在一定的速度漩涡,使得局部压力降低而产生空化;空泡首先在叶片吸力面进口稍后靠近前盖板的位置产生,然后沿叶片吸力面向出口方向扩散,且其空泡体积分数逐渐减小;随着流量的增大,空泡体积分数逐渐增大。模拟结果较好地反映了离心泵内空化发生的过程,为空化特性的研究提供一定的理论依据。
In order to study internal flow mechanism under the cavitation in a centrifugal pump, the RNG K - 6 turbu- lence model and wall-function method were applied to simulate the three-dimensional turbulent flow cavitation character- istics in a centrifugal pump with specific speed of 47 under different working conditions based on Fluent software. The static pressure distribution , the velocity distribution and the vapor bubbles volume fraction distribution on middle stream surface of impeller and middle stream line of blade under different working conditions were analyzed. The results show that there is lower pressure zone in the inlet later on place of suction side of blade, which is just the incipience of the cavitation; there are some velocity vortexes in the impeller inlet, and it leads to some areas pressure reduce to take place the cavitation ; the vapor bubbles generate at suction side of blade near the leading edge at first and then extend to the out- let of impeller and the vapor bubbles volume fraction gradually decrease; the vapor bubbles volume fraction enlarge by degrees with the increasing of the flow rate . The simulation results are reasonable on performance process of cavitation in the centrifugal pump , which provide theoretical basis for study of cavitation characteristics.
出处
《农机化研究》
北大核心
2012年第11期59-63,72,共6页
Journal of Agricultural Mechanization Research
基金
国家标准化管理委员会项目(2007A4308-T-604)
江苏省科技服务业计划项目(BM2008375)
关键词
离心泵
空化
数值模拟
FLUENT
流场
centrifugal pump
cavitation
numerical simulation
Fluent
flow field
