| This article has been：Browse 1390Times Download 3215Times |
scan it! |
|
|
| DOI：10.13522/j.cnki.ggps.2021247 |
|
| Numerical Analysis of Internal Flow in a Slanted Axial-flow Pump |
|
HU Wenzhu, TONG Daobin, LI Zhongbin, et al.
|
|
1. College of Hydraulic Science and Engineering, Yangzhou University, Yangzhou 225127, China;
2. Sucheng Water Conservancy Project Construction Service Center, Suqian 223800，China;
3. Hydrodynamic Engineering Laboratory of Jiangsu Province, Yangzhou 225009, China
|
| Abstract: |
| 【Background and objective】Slanted axial-flow pump has the advantages of small excavation depth, stable flow pattern and high efficiency. It has been widely used in large and medium-sized low head pumping stations. With the improvement in water conveyance and distribution projects and irrigation and drainage in China, the requirement for hydraulic performance of the slanted axial-flow pump has increased. The objective of this paper is to numerically analyze internal flow in the flow channel in the slanted axial-flow pump.【Method】The 3D numerical analysis was based on CFD for a 30° slanted axial-flow pump, from which we obtained the internal geometry of the flow pathways for different flow conditions. We then analyzed the section velocity nephogram, the axial uniformity of the outlet and the weighted average velocity angle of the elbow inlet channel. We also showed the pressure distribution over the impeller blades and sections of guide vanes, as well as the vortex structure distribution in the straight pipe outlet channel.【Result】There was a noticeable velocity gradient at the outlet of the elbow inlet channel. Under optimal flow condition, the uniformity of the axial velocity in the outlet section of the inlet channel was 93%, and the velocity weighted average angle was 85.2°. With the increase in flow rate, the high pressure area over the impeller blade shifted from the inlet towards the outlet, and the pressure over the blade was regularly distributed. As the flow rate increased, the velocity circulation in the outlet section in the guide vanes decreased first followed by an increase, while the velocity circulation at the outlet section of the guide vane was the lowest under 1.0Qbep flow condition. Most vortex bands in the elbow section of the straight pipe outlet channel were long strips, distributed predominately at the inlet of the elbow near the pump shaft.【Conclusion】The flow pattern inside the slanted axial flow pump was relatively uniform, and the elbow inlet channel can provide a good flow pattern in the impeller. Verification revealed that the model for the slanted axial-flow pump gave results consistent with experimental data. |
| Key words: slanted axial-flow pump; pump installation; internal flow; hydraulic performance; numerical simulation |
|
|
