气隙激振力对转子临界转速的影响

Influence of Flow Gap Induced Exciting Forces on Critical Speeds of Rotors

从诱发汽流激振的原因出发,指出气隙激振力是汽轮机组发生汽流激振的主要原因,并以Riccati传递矩阵法为框架,建立能够处理包括气隙激振力在内的各种激振源对转子临界转速影响的计算模型。利用该模型就气隙激振力对转子临界转速的影响进行了计算分析,通过与试验台实测的结果对比分析,验证了计算模型的可靠性,得出了临界转速的下降量随着充气压力的提高而增大的结论。该计算模型今后还可应用于转子稳定性及汽流激振的分析研究。

Starting from the fact that flow gaps may cause vibration exciting forces, it is pointed out that such forces are the main genesis of flow incited vibration of steam turbines; a calculation model is further being constructed, using Riccati transfer matrix computation as the framework, capable of calculating the effect, on critical speed, of all kinds of vibration exciting sources, including flow gap initiated. In this way, the effect of flow gap on the critical speed of a rotor has been calculated, and a comparison with test rig measurements shows that the calculation model is reliable; concluding that the drop of the critical speed gets larger with increasing pressure of flow. This calculation model can henceforth also be used for analyzing rotor stability and flow incited vibration.