采用计算流体力学与结构动力学相结合的方法,数值模拟了三维振荡叶栅非定常黏性流场;通过对叶片表面非定常气动力及其所做非定常气动功的计算分析,采用能量法对叶片颤振与否进行预估判断。针对三维直叶片和风扇转子叶片,通过调整叶片的相对厚度,研究了叶片厚度变化对风扇/压气机颤振特性的影响。此外,通过对振荡叶栅非定常流场结构的研究,发现了叶片吸力面气流分离与叶片振动之间的耦合关系。本文的研究在风扇/压气机设计中,可用于评估最大相对厚度等叶型结构设计参数对气弹稳定性的影响,对叶轮机颤振机理研究具有一定的参考意义。
By using computational fluid dynamics and structural dynamics methods, the 3D viscous unsteady flow around oscillating cascades is numerically simulated. Through the computation and analysis of unsteady aerodynamic forces loading on the cascades and aerodynamic work, the probability of blade flutter is predicted through the energy method. The flutter characteristics of linear blades and fan rotors with various thickness are numerically analyzed respectively, and the influence of blade thickness and its variation on flutter characteristics is initially studied. Through studying the structure of the unsteady flow field in vibrating cascades, the coupling relationship between flow separation on the suction surface and blade vibration is revealed. The research results can be used to study the effect of structure design parameters such as maximum thickness on the aeroelastic stability in the fan/compressor design, and it is of value for reference in turbomachinery flutter mechanism research.