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在输/排水管道的快速填充过程中常会出现含滞留气团的复杂气—水两相瞬变流,极有可能引发异常的压力波动,从而导致严重的水力过载甚至爆管事故。目前,对于这种特殊瞬变流现象的研究基本采用一维方法或观测视角,无法准确反映气团的动态特性。为此,基于计算流体力学(CFD)模拟方法,采用5种湍流模型对该瞬变流问题进行了二维(2D)数值模拟,并将其瞬态压力、水气耦合分布模拟与试验结果进行比较。结果表明,CFD模拟方法能有效模拟水气分布及压力动态变化;标准κ-ε和标准κ-ω模型计算的最大压力误差较小,RNG模型的压力波动周期吻合度最好,两种κ-ω模型的气团模拟效果欠佳。
In the process of rapid filling of the pipelines / drains, complicated gas-water two-phase transient flow with entrapped air mass often appears, which may lead to abnormal pressure fluctuations, leading to serious hydraulic overload and even burst pipe accidents. At present, the study of this special transient flow phenomenon basically adopts one-dimensional method or observation perspective, which can not accurately reflect the dynamic characteristics of the air mass. Therefore, based on Computational Fluid Dynamics (CFD) simulation method, five kinds of turbulence models are used to simulate the transient flow and the simulation and experimental results of transient pressure, moisture and gas coupling are carried out Compare The results show that the CFD simulation method can effectively simulate the distribution of water vapor and the dynamic changes of pressure. The maximum pressure error calculated by standard κ-ε and standard κ-ω models is small, and the RNG model has the best periodicity of pressure fluctuation. The air mass simulation of ω model is ineffective.