A Numerical Study of Flutter in a Transonic Fan
A Numerical Study of Flutter in a Transonic Fan
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跨音速风扇颤振的数值研究
DOI：
10.1115/97-gt-235
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
M. Giles
中科院分区：
文献类型：
--
作者：
K. Isomura;M. Giles
采用准三维粘性非定常计算流体动力学程序研究了一台现代跨音速风扇的弯曲模态颤振。本研究中的颤振类型是叶尖相对马赫数刚好大于1的高载荷叶片的颤振，通常称为跨音速失速颤振。这种类型的颤振在现代宽弦风扇中经常遇到，没有部分跨度的护罩。CFD模拟使用了Roe的三阶通量差分的迎风格式，以及约翰逊和King的湍流模型，以及约翰逊和Coakley的后期修改。本文用en方法和Schubauer和Klebanoff的实验数据建立了一个动态转捩点模型，计算了该风扇的流动，揭示了IHI跨音速风扇的颤振源是通道激波的振荡，而不是失速。随着叶片载荷的增加，通道激波向前移动。就在通道激波未启动之前，通道激波的稳定性降低，并且小的叶片振动导致激波在未启动位置和启动位置之间以大的振幅振荡。叶片激振力的主要分量是由于叶片压力表面上振荡通道激波的根部。版权所有© 1997 by ASME
The bending mode flutter of a modern transonic fan has been studied using a quasi-3D viscous unsteady CFD code. The type of flutter in this research is that of a highly loaded blade with a tip relative Mach number just above unity, commonly referred to as transonic stall flutter. This type of flutter is often encountered in modern wide chord fans without a part span shroud.The CFD simulation uses an upwinding scheme with Roe’s 3rd-order flux differencing, and Johnson and King’s turbulence model with the later modification due to Johnson and Coakley. A dynamic transition point model is developed using the en method and Schubauer and Klebanoff’s experimental data.The calculations of the flow in this fan reveal that the source of the flutter of IHI transonic fan is an oscillation of the passage shock, rather than a stall. As the blade loading increases, the passage shock moves forward. Just before the passage shock unstarts, the stability of the passage shock decreases, and a small blade vibration causes the shock to oscillate with a large amplitude between unstarted and started positions. The dominant component of the blade excitation force is due to the foot of the oscillating passage shock on the blade pressure surface.Copyright © 1997 by ASME