A numerical study of flutter in a transonic fan
- Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan). Aero-engine and Space Operations
- Oxford Univ. Computing Lab. (United Kingdom)
The bending mode flutter of a modern transonic fan has been studied using a quasi-three-dimensional 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 third-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 e{double_prime} method and Schubauer and Klebanoff`s experimental data. The calculations of the flow in this fan reveal that the source of the flutter of 1H1 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.
- OSTI ID:
- 290041
- Report Number(s):
- CONF-970604--
- Journal Information:
- Journal of Turbomachinery, Journal Name: Journal of Turbomachinery Journal Issue: 3 Vol. 120; ISSN JOTUEI; ISSN 0889-504X
- Country of Publication:
- United States
- Language:
- English
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