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

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 400∘ C 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 peakpressure 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.

A numerical investigation into the aerodynamic effect of pressure pulses on a tunnel ventilation fan

“…18 They used the open source code OpenFOAM, a code previously validated by researchers studying the flow-field in both aerospace and industrial turbomachinery applications. 19–26…”

“…18 They used the open source code OpenFOAM, a code previously validated by researchers studying the flow-field in both aerospace and industrial turbomachinery applications. [19][20][21][22][23][24][25][26] In this paper, the authors first describe the tunnel ventilation fan that is the subject of the reported research and consider the tunnel ventilation system applications into which they have installed it. They then define the pressure pulses to which they have subjected the fan and clarify the computational approach that occurs with their modelling.…”