Computation of aerodynamic noise of centrifugal fan using large eddy simulation approach, acoustic analogy, and vortex sound theory

Abstract

Large eddy simulation is applied to solve the unsteady three-dimensional viscous flow in the whole impeller-volute configuration of a centrifugal fan. The results of the simulation are used to predict the impeller-volute interaction and to obtain the unsteady pressure, velocity, and vorticity fluctuations in the impeller and volute casing. The simulation at the design point is carried out with the wall-adapting local eddy-viscosity subgrid-scale model and a sliding mesh technique is applied to consider the impeller-volute interaction. The results show that a strongly unsteady flow field occurs in the impeller and volute casing of the fan, and the flow is characterized with obvious pressure and vorticity fluctuations, especially at the tongue and at the blade wake region. The large pressure fluctuation at the tongue and the large fluctuation of the blade wake vorticity appear as the blade wake is passing the tongue. Acoustic analogy and vortex sound theory are used to compute the radiated dipole and quadrupole sound fields, which are in good agreement with the experiment. The sound results show that the vortex sound theory is convenient for the broadband noise computation, and the dipole sound is much higher than the quadrupole sound. The dipoles, distributed over the volute tongue surface, are the dominant sound source of the fan.

Experimental study on the noise reduction of an industrial forward-curved blades centrifugal fan

“…To the best knowledge of authors, only few literatures have been presented on the noise generation mechanism and control method for the industrial FC blades centrifugal fan [21,22]. The difficulties are that the efficiency of FC blades centrifugal fan is lower, but the noise level is higher than that of the FC multi-blade and BC blades centrifugal fans with the same volute and impeller outlet diameter.…”

A Numerical Study on the Distribution and Evolution Characteristics of an Acoustic Field in the Time Domain of a Centrifugal Pump Based on Powell Vortex Sound Theory

“…By using Green function, the analytical solution of the equation could be derived to solve the noise signal in time domain at a certain monitoring point. Liu et al [24], Ouyang et al [25] and Wang et al [26] applied the analytical solution to aerodynamic noise computation of fans and noise directivity characteristics analysis of submerged jet, respectively.…”

Numerical optimization for radiated noises of centrifugal pumps in the near-field and far-field based on a novel MLGA-PSO algorithm

“…Noises of centrifugal pumps include structural vibration-induced noises and fluid-induced noises [9][10][11]. Structural vibration-induced noises are from structural design and manufacture, and have been solved by active control technologies.…”