Towards Understanding LES and DES for Industrial Aeroacoustic Predictions

Abstract

Computational Aeroacoustics combines the multi-disciplines of Computational Fluid Dynamics and Computational Acoustics. The former solves the time-dependant Navier-Stokes equations but relies on modelling turbulence, which is central to the correct prediction of aeroacoustic sources. It must be capable of capturing narrowband and broadband acoustics, the former manifested as tonal modes that cause discomfort, and both types of which may be significant contributors to component fatigue failure. This paper describes an analysis process, which has begun to show substantial value in both the preliminary design and production life cycles. It is founded on LES-type turbulence modelling, hitherto almost exclusively the domain of research departments and institutions, yet latterly has potential to become an industrial analysis tool through the combined advance in processing power and efficiencies realised through Detached Eddy Simulation (DES) turbulence modelling. Keywords: STAR-CD, Aeroacoustic sources, dipoles and quadrupoles, narrowband and broadband noise, DES 1. Introduction 2. Aeroacoustic Analysis Tool-kit Real challenges to suppress undesirable fluidexcited acoustics are posed by a wide variety of engineering disciplines. Noise regulations,