Analytical investigation of the SAFE diagram for bladed wheels, numerical and experimental validation
Analytical investigation of the SAFE diagram for bladed wheels, numerical and experimental validation
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DOI：
10.1016/j.jsv.2014.04.061
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发表时间：
2014-09
影响因子：
4.7
通讯作者：
L. Bertini;P. Neri;C. Santus;A. Guglielmo;G. Mariotti
中科院分区：
文献类型：
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作者：
L. Bertini;P. Neri;C. Santus;A. Guglielmo;G. Mariotti
压缩机和涡轮叶轮与定子叶片分配的流体相互作用。它们会受到振动和疲劳载荷的影响，尤其是在激发共振条件时。设计叶轮时避免共振是基础。坎贝尔图方法过于保守，因为叶轮显示出许多接近的频率自然模式，因此几乎不可能避免频率匹配。辛格的高级频率评估（SAFE）图或干扰图除了频率之外还引入了形状匹配来进行共振预测，因此许多频率匹配情况可以被识别为非关键情况，从而可以容忍。本文通过引入解析表达式来识别叶轮共振条件，解释并演示了 SAFE 图。通过具体算例研究了模态振型与谐波分量的匹配。还介绍并论证了谐波指数和模态形状的匹配分布的对称性。最后，叶轮分析用于有限元模拟和实验中的验证。
Compressor and turbine bladed wheels interact with the fluid distributed by the stator vanes. They are subject to vibration and fatigue loading, especially when resonance conditions are excited. Avoiding resonance is fundamental when designing bladed wheels. The Campbell diagram approach is too conservative since bladed wheels show many close frequency natural modes, thus it is almost impossible to avoid frequency matching. Singh׳s Advanced Frequency Evaluation (SAFE) diagram, or interference diagram, also introduces shape matching in addition to the frequency, for resonance prediction, therefore many frequency matching cases can be identified as non-critical and thus tolerated. The present paper explains and demonstrates the SAFE diagram by introducing an analytical expression to identify bladed wheel resonance conditions. The mode shape matching with a harmonic component is investigated by means of specific examples. Symmetry properties of the matching distribution of harmonic indices and mode shapes are also introduced and demonstrated. Finally, a bladed wheel analysis is used for validation, both in FE simulations and experiments.