CFD ANALYSIS OF FLOWFIELD IN A GENERIC ENGINE NACELLE

This paper deals with the study of airflow in an uncluttered nacelle, as an important first step in setting up the basis for further analysis of suppressant transport within an aircraft engine nacelle. This initial study will help establish a viable CFD model to study the nacelle air flow conditions at typical Reynolds numbers, by studying the effects of different turbulence models, boundary conditions as well as the computational grids used in the simulation. Initial boundary conditions were derived from a report by Sandia National Laboratories (SNL). Validation cases were run using different input conditions, based on either the experimental conditions or based on a user-defined function and the validity of current simulations were ascertained by comparing velocity profiles and turbulence intensity profiles at different measurement stations. Effects of the computational grids were examined by carrying out a grid sensitivity study. The sensitivity of the simulations to different turbulence models, was also studied, to see if the discrepancies in the velocity and turbulence intensity profiles, near the walls, noticed in some sections, could be resolved. The current simulations showed reasonable agreement to the experimental data and very good agreement with the CFD-ACE obtained data from the simulations performed by SNL.