| 曾永顺,齐鑫,姚志峰,王福军.空化对振动水翼附加质量和阻尼特性影响研究[J].水利学报,2023,54(9):1133-1140 |
| 空化对振动水翼附加质量和阻尼特性影响研究 |
| Influence of cavitation on the added mass and damping characteristics of a vibrating hydrofoil |
| 投稿时间：2023-02-12 |
| DOI：10.13243/j.cnki.slxb.20230067 |
| 中文关键词: 水翼 空化 双向流固耦合 固有频率 水力阻尼 |
| 英文关键词: hydrofoil cavitation two-way FSI added mass hydrodynamic damping ratio |
| 基金项目:国家自然科学基金项目(52179092) |
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| 中文摘要: |
| 抽水蓄能机组需频繁调节工况以适应电网需求。由此水力激振频率范围加宽，共振风险增加。附加质量和阻尼特性是评估共振工况点和共振幅值的关键参数。在空化发生时，叶片绕流流体从液相变成汽相，其复杂的流固耦合效应对叶片附加质量和阻尼特性产生影响。本文将叶片简化为NACA 0009水翼，探索了空化发生时基于双向流固耦合的附加质量和水力阻尼特性预测方法。结果表明，模拟得到的静水中固有频率和不同空化数下的空化脱落频率与实验结果吻合良好，相对误差分别在7.12%和8.76%以内。在空化数σ=1.04~2.02范围内，固有频率和水力阻尼随空化数的降低分别增大和减小，相对于实验的平均误差分别为9.69%和13.65%。内部流动分析表明反向射流导致前缘空化周期性脱落，吸力面的绕流速度下降则是空化发生后水力阻尼下降的主要原因。研究成果对抽水蓄能机组设计阶段预判空化时的叶片振动评估具有重要指导意义。 |
| 英文摘要: |
| Pumped storage units need to frequently adjust their operating conditions to meet the needs of the electric grid.This widens the frequency range of the hydraulic excitation and increases the risk of resonance.Added mass and damping characteristics are key parameters for evaluating the resonance operating point and resonance amplitude，respectively.When cavitation occurs，the fluid flowing around the blade changes from liquid phase to vapor phase，and its complex fluid-structure interaction (FSI) affects the added mass and hydrodynamic damping characteristics of a blade.In this paper，the blade is simplified as a NACA 0009 hydrofoil，and the prediction method of added mass and hydrodynamic damping characteristics based on two-way FSI is explored under cavitation conditions.The results show that the simulated natural frequency in still water and the cavitation shedding frequency under different cavitation numbers are in good agreement with the experimental results，and the relative errors are within 7.12% and 8.76%，respectively.When the cavitation number is in the range of 1.04-2.02，the natural frequency and hydrodynamic damping increase and decrease respectively with the decrease of cavitation number，and the average errors relative to the experiment results are 9.69% and 13.65%，respectively.The internal flow analysis shows that the re-entrant jet causes the cavitation at the leading edge to shed periodically，and the decrease in the flow velocity around the suction surface may be the main reason for the decrease in hydrodynamic damping after the cavitation occurs.The research results have important guiding significance for the blade vibration evaluation under the cavitation condition in the design stage of a pumped storage unit. |
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