Session: 01-04 Inlets, Ducts & BLI

Paper Number: 81805

81805 - Unsteady Analysis of Aeroengine Intake Distortion Mechanisms: Vortex Dynamics in Crosswind Conditions 

The formation of a ground vortex and its ingestion into an aero-engine intake under crosswind conditions play a significant role in the aerodynamic excitation of fan vibrations. Using steady and unsteady numerical simulations, the intake distortion metrics for a simplified aero-engine intake are determined using established metrics such as DC60. However, these do not convey sufficient information from a fan forcing perspective. Thus, the need arises to develop new metrics which would adequately represent the intake distortion flow features such as ground vortex and lip separations. For the simplified intake at high crosswind velocities, there is substantial movement of the ingested ground vortex at the aerodynamic interface plane. The ingested ground vortex moves azimuthally varying both in size and strength, exhibiting periodicity. Circumferential mode decomposition shows that the largest amplitude of the distortion occurs at the first circumferential mode, and the amplitudes of the higher modes decrease linearly. Furthermore, the amplitude of the spatial harmonics are time dependant, and a new distortion metric to account for these variations is proposed. The sensitivities to the magnitude of the approaching crosswind velocities, the height of the intake above the ground plane and to the direction of approaching crosswind are also accounted for, with the aim of developing reduced order model to predict intake distortions.

Presenting Author: Anirudh RAO Imperial College London

Presenting Author Biography: Anirudh Rao is a Research Associate at Imperial College London working with the VIbration UTC at the Dept. of Mechanical Engineering.

Authors:

Anirudh RAO Imperial College London
Prathiban Sureshkumar Imperial College London
Sina Stapelfeldt Imperial College London
Bharat Lad Rolls Royce
Kuen-Bae Lee Rolls Royce
Ricardo Puente Rico Imperial College London