Session: 01-06 Inlet Distortion and Engine Operability

Paper Number: 102227

102227 - Optimal Cfd Strategy for Intake Ground Vortex Ingestion in Crosswind Conditions 

Nacelles operating close to the ground in crosswind conditions can ingest a ground vortex into the intake and experience lip separation on the windward side. Over the past decades, experimental and numerical investigations have been conducted using full and scaled models to understand this phenomenon. However, accurate numerical predictions remain challenging due to the unsteady nature of the ground vortex. The main objective of this paper is to demonstrate the importance of numerical setup and determine the optimal computational model for ground vortex investigations. By considering vortex motion to be inherently unsteady, the influence of turbulence modelling fidelities, inlet and exit boundary conditions, and grid convergence are studied in an unsteady manner using URANS and DDES. Numerical predictions of the time-averaged intake pressure recovery (IPR) and the standard deviation of the vortex motion on the ground are validated against the existing experimental data. Results showed that grid convergence could not be achieved using steady-state computations due to large-scale flow fluctuation at high crosswind conditions. The intake flow separation and ground vortex predictions were influenced by the turbulence model and inlet boundary layer profiles. Moreover, acoustic reflection was observed at the intake exit boundary due to the motion of the ingested vortex, hence modifying the frequency of vortex oscillation; this was mitigated using a choked nozzle at the intake exit, which eliminates boundary reflections. Finally, guidelines for ground vortex computational modelling at crosswind conditions are presented.

Presenting Author: Venkata Y. T. Chennuru Universidad Politécnica de Madrid

Presenting Author Biography: Finished my bachelor's from NIT Trichy in India and then pursued a master's degree in the THRUST program at KTH. Currently, I am a PhD student under Professor Roque Corral at the Polytechnic University of Madrid.

Authors:

Venkata Y. T. Chennuru Universidad Politécnica de Madrid
Fanzhou Zhao Imperial College London
Mehdi Vahdati Imperial College London