Session: 22-01 Fan and LPT Flutter

Paper Number: 153338

Fan Flutter at Mild Wind Conditions at Sea-Level-Static 

This paper investigates the impact of ground vortex on the flutter stability of a fan blade during Sea-Level-Static (SLS) operation under light or zero crosswind conditions. Typically, flutter rig tests or CFD simulations are performed assuming clean intakes without considering the ground plane. However, when an aircraft engine operates close to the ground in static or near-static conditions, a strong vortex forms at the ground plane and is ingested into the intake. With the rise of Ultra-High Bypass Ratio (UHBR) engines, with shorter intakes and reduced ground clearances, it becomes crucial to determine whether (and how) distortions such as ground vortex influence the flutter stability of the fan blade. A three-dimensional unsteady Computational Fluid Dynamics (CFD) model is used to analyse the phenomenon. Initial findings indicate that under static engine conditions with light or zero crosswind, the ground vortex modifies the intake acoustics, which in turn influences the flutter stability of the fan blade, potentially leading to a reduced flutter margin in some cases. To the best of the authors’ knowledge, this is the first time the effects of ground vortex on fan blade flutter stability have been presented, offering valuable insights for aero-engine manufacturers and researchers in the field of aeroelasticity.

Presenting Author: Venkata y.t. Chennuru Universidad Politécnica de Madrid

Presenting Author Biography: Venkata got his dual degree in master’s from THRUST program at KTH in Stockholm and University of Liege. Currently, he is a third Ph.D. student under Prof. Roque Corral, working on fan flutter under distortion at the Politechnic University of Madrid.

Authors:

Venkata y.t. Chennuru Universidad Politécnica de Madrid
Roque Corral Universidad Politécnica de Madrid
Fanzhou Zhao Imperial College London
Salvador Rodríguez-Blanco Universidad Politécnica de Madrid
Mehdi Vahdati Universidad Politécnica de Madrid