轴向间距对转子叶片颤振特性的影响机理

摘要

The mechanism of the upstream blade row affecting the flutter characteristics of the rotor blade is studied,using the self-developed unsteady fluid-solid coupling numerical simulation program.The influence coefficient method is used to analyze the effect of axial spacing on the aeroelastic stability of rotor.The results show that the neighboring blade vibration,which adjacent to the certain blade's suction side,determines the value of rotor aerodynamic damping in the tuned cascade, and its effect is even larger than the certain blade vibration itself;in the multi-row environment, inlet guide vanes(IGV)mainly affects the minimum aerody-namic damping of rotor blade,and IGV increases the nodal diameter value of the most unstable point of aero-elasticity;the channel change caused by blade vibration restrains the reflection of IGV on unsteady pressure wave; with the decrease of axial spacing, the range of unsteady influence of blade vibration is obviously in-creased,since the effect of IGV on the unsteady pressure wave attenuates the circumferential attenuation of un-steady pressure wave;the influence coefficient method needs to measure more blades to obtain more accurate aerodynamic damping in the multi-row environment.%使用自行开发的非定常流固耦合数值模拟程序,研究了上游叶排影响转子叶片颤振特性的机理,采用影响系数法分析轴向间距影响转子气动弹性稳定性的规律.结果表明:在协调叶栅中,叶片吸力面相邻的叶片振动对转子叶片气动阻尼的大小起决定性作用,其影响甚至超过振动叶片本身的影响;多排环境中,导叶(IGV)对转子叶片气动阻尼最小值的影响最大,并使其对应的节径增大;相邻叶片振动引起的通道变化抑制了导叶对非定常压力波的反射作用;随着轴向间距的减小,导叶对非定常压力波的反射作用减弱了非定常压力波的周向衰减,从而增大了叶片振动的非定常影响范围;在多排环境中使用影响系数法需要测量更多的叶片才能得到较为准确的气动阻尼.