旋流自吸泵气液两相流数值模拟

Gas-liquid two-phase flow numerical simulation of a vortex flow self-priming pump

采用雷诺时均N-S方程和RNGk-ε湍流模型,使用多相流模型中的混合物模型,通过商用软件FLUENT,对自吸时旋流自吸泵内气液两相流场作了数值模拟.在对蜗壳流道和叶轮流道进行网格划分时,尺寸扭曲率为0.78.根据模拟结果,将泵内两相流场的静压分布,与单液相时的静压分布作了对比,并比较了叶轮内气相与液相相对速度的分布情况.另外,对含气率的分布情况作了分析.结果表明,自吸时气液两相状态下的静压稍小于单液相状态下的静压;泵内的主要流动是液相通过相间作用夹带气相的流动,液相速度略大于气相速度;靠近泵出口的两个叶道内,有气相的积聚,含气率较高.

Gas-liquid two-phase flow of a vortex flow self-priming pump under self-priming condition was simulated by using reynolds time-averaged N - S equations, RNG k - ε turbulent model, and mixer model of multi-phase models in FLUENT. When the channel of impeller and volute were meshed, the size distortion rate was 0.78. The static pressure distribution of the pump from two-phase flow simulation was compared with that from single phase flow, and the relative velocities of the impeller between gas phase and liquid phase were compared. The distribution of gas volume fraction was analyzed. The results show that the static pressure of gas-liquid two-phase is slightly less than that of single-phase when self-priming. The main flow of the pump is the flow of liquid phase with the flow of gas through the phase entrainment effect. Liquid velocity is slightly larger than that of gas. The two channels near the outlet of the pump have obvious gas accumulation with higher gas voids.