Fluid-structure interactions in Francis turbines : A perspective review
Fluid-structure interactions in Francis turbines : A perspective review
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DOI：
10.1016/j.rser.2016.09.121
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发表时间：
2017-02
影响因子：
15.9
通讯作者：
C. Trivedi;M. Cervantes
中科院分区：
文献类型：
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作者：
C. Trivedi;M. Cervantes
具有竞争力的电价和降低的利润率迫使水轮机在关键条件下运行。对更大运行范围的需求和涡轮机转轮的高效率迫使制造商生产轻量化的转轮。当强制(流激)激励频率接近转轮的固有频率时，水轮机转轮有时会发生共振，从而导致故障。投产后发生结构故障的成本高得令人望而却步。为了获得可靠和安全的流道设计，了解流激的结构响应是很重要的。高幅度的压力脉动会导致叶片的疲劳载荷，随着时间的推移，叶片会出现裂纹。幅值取决于流动条件、涡轮机类型和定子/转子叶片组合。结构响应取决于材料特性、流致阻尼和固有频率。此外，在水轮机中，流速从不到1米的S−1到超过40米的S−1给响应预测带来了挑战。综述了流致激振、附加质量效应、流体动力阻尼和叶片颤振等方面的研究进展。本文从实验和数值研究两个方面进行了讨论。本文还讨论了增加的过渡循环次数，如负荷变化、启停和总负荷甩出对汽轮机和疲劳负荷的影响。最后，试图强调未来流体结构分析的重要要求，以填补目前文献中的空白。
Competitive electricity prices and reduced profit margins have forced hydraulic turbines to operate under critical conditions. The demand for extended operating ranges and the high efficiency of the turbine runners have forced manufacturers to produce lightweight runners. A turbine runner sometimes experiences resonance when a forced (flow-induced) excitation frequency approaches the runner’s natural frequency, resulting in failure. The cost of structural failure after commissioning is prohibitive. To attain a reliable and safe runner design, understanding of the structural response to flow-induced excitations is important. High amplitude pressure pulsations cause fatigue loading of the blades, which develop cracks over time. The amplitudes are dependent on the flow conditions, type of turbine and stator/rotor vane combinations. The structural response is dependent on the material properties, flow-induced damping and natural frequencies. Moreover, in a hydraulic turbine, changes in flow velocity from less than 1 m s−1to over 40 m s−1create challenges in predicting the response.The main objective of this article is to review the studies conducted on fluid-structure interactions within hydraulic turbines. Several aspects are reviewed, such as flow-induced excitation, added mass effect, hydrodynamic damping, and blade flutter. Both experimental and numerical studies are discussed in this article. This review also discusses the consequences of an increased number of transient cycles, such as load variation, start-stop and total load rejection, on the turbines and the fatigue loading. Finally, an attempt is made to highlight the important requirements for prospective fluid-structure analysis to fill current gaps in the literature.