| 引用本文: | 全 莉,刘 颖,吴泽昊,等.平面S型轴伸贯流泵装置泵内流动特性研究[J].灌溉排水学报,2023,42(3):90-96. |
| QUAN Li,LIU Ying,WU Zehao,et al.平面S型轴伸贯流泵装置泵内流动特性研究[J].灌溉排水学报,2023,42(3):90-96. |
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| 摘要: |
| 【目的】探究低扬程泵站平面S型泵装置内压力脉动特性和流动稳定性。【方法】采用软件CFX开展三维全流道数值模拟，湍流模型选择为RNG k-ε。采用快速傅里叶变换对压力信号进行处理，在Ansys后处理系统中对流场数据进行可视化处理。分析了小流量工况0.8 Qd、设计工况Qd和大流量工况1.2 Qd等3个典型工况下泵装置内的流动特性、压力脉动特性和涡量分布特性。【结果】进水流道内水流流态稳定，流量工况主要影响出水流道内的流动稳定；叶轮内压力脉动激励源为叶轮的旋转作用，在叶轮进口脉动频率成分复杂，主频为叶频；而叶轮出口脉动幅值较小，存在明显的低频脉动；进水流道内水流涡量接近0，叶轮室、导叶室和出水流道内的涡量差别很大，受到叶轮的旋转扰动叶轮室内和导叶室内流场涡量最大。小流量工况下泵段和出水流道内的涡量差异最大，随着流量的增大涡量减小。【结论】涡量分布规律与泵装置内流态变化一致，这从能量的角度解释了不同流量工况下流动稳定差异的原因。研究结果对充分了解平面S型泵装置内流动特性和流动稳定机理提供理论指导，对工程运行提供借鉴意义。 |
| 关键词: 平面S型轴伸贯流泵；涡量；压力脉动；流动特性；数值模拟 |
| DOI：10.13522/j.cnki.ggps.2022208 |
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| Flow Characteristics in Plane S-type Axial Extended Tubular Pump |
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QUAN Li, LIU Ying, WU Zehao, YAN Jie
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Yangzhou Survey, Design and Research Institute, Yangzhou 225009, China
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| Abstract: |
| 【Objective】The S-type axial extended tubular pump is a device widely used in various hydraulic engineering projects. The objective of this paper is to analyze the pressure pulsation characteristics and flow stability in the pump under different working conditions in low-lift stations.【Method】Three-dimensional full-channel numerical simulation is carried out with software CFX, and the turbulence model is selected as RNG k-ε. Fast Fourier transform (FFT) is used to process the pressure signal, and the flow data is visualized in the Ansys Post system. The flow characteristics, pressure pulsation characteristics and vorticity distribution characteristics in the pump unit under three typical conditions, 0.8 Qd, Qd and 1.2 Qd (Qd is the design flow condition) were analyzed.【Result】Flow pattern in the inlet of the channel is stable, and flow stability in the outlet of the channel is mainly affected by flow condition. The impeller's rotation serves as the excitation source of pressure pulsation in the pump, and there are high-order harmonics of blade frequency at the inlet of the impeller. The amplitude of high-order harmonics at the outlet of the impeller is small, and there are complex frequency components at the outlet of the guide vane, along with evident low-frequency pulsations. We also find that the flow vorticity in the inlet passage is zero, while the vorticity in the impeller chamber, guide vane chamber, and outlet passage is highly diverse. Due to the rotation disturbance of the impeller, the vorticity in the flow field in the impeller chamber and guide vane chamber is the largest. Under low flow condition, the difference in vorticity between the pump section and the outlet channel is the highest, while the vorticity decreases with increasing flow. This is consistent with the change of flow pattern in the pump device, thereby explaining, from an energy perspective, the reason for variation of the flow stability under different flow conditions.【Conclusion】Our results provide guidance for comprehending the mechanisms underlying flow characteristics and stability in the plane S-type pump device. They are helpful for engineering design. |
| Key words: plane S-type axial extension tubular pump; vorticity; pressure pulsation; flow characteristics; numerical simulation |
