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Advances in Acoustics and Vibration
Volume 2013 (2013), Article ID 876973, 10 pages
http://dx.doi.org/10.1155/2013/876973
Research Article

Large-Eddy Simulation of the Aerodynamic and Aeroacoustic Performance of a Ventilation Fan

1Department of Mechanical and Aerospace Engineering, Sapienza, University of Rome, Via Eudossiana, 18, 00184 Roma, Italy
2Fläkt Woods Ltd., Axial Way, Colchester CO4 5ZG, UK

Received 4 October 2012; Accepted 18 January 2013

Academic Editor: Abul Azad

Copyright © 2013 Stefano Bianchi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

There are controversial requirements involved in developing numerical methodologies in order to compute the flow in industrial fans. The full resolution of turbulence spectrum in such high-Reynolds number flow configurations entails unreasonably expensive computational costs. The authors applied the study to a large unidirectional axial flow fan unit for tunnel ventilation to operate in the forward direction under ambient conditions. This delivered cooling air to the tunnel under routine operation, or hot gases at 400C under emergency conditions in the event of a tunnel fire. The simulations were carried out using the open source code OpenFOAM, within which they implemented a very large eddy simulation (VLES) based on one-equation SGS model to solve a transport equation for the modelled (subgrid) turbulent kinetic energy. This subgrid turbulence model improvement is a remedial strategy in VLES of high-Reynolds number industrial flows which are able to tackle the turbulence spectrum’s well-known insufficient resolution. The VLES of the industrial fan permits detecting the unsteady topology of the rotor flow. This paper explores the evolution of secondary flow phenomena and speculates on its influence on the actual load capability when operating at peak-pressure condition. Predicted noise emissions, in terms of sound pressure level spectra, are also compared with experimental results and found to agree within the uncertainty of the measurements.