Rotating Coherent Flow Structures as a Source for Narrowband Tip Clearance Noise from Axial Fan

Zhu, Tao; Lallier-Daniels, Dominic; Sanjosé, Marlène; Moreau, Stéphane; Carolus, Thomas

doi:10.2514/6.2016-2822

Cited by 6 publications

(3 citation statements)

References 26 publications

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“…Such characteristics make the LBM, straightforward to code with a very good parallel efficiency, particularly adequate for solving complex fluid flows and wave propagation with complicated geometry (e.g. Shin et al, 8 Zhu et al 9 ). The simulation of turbulent flows can be achieved, as for NS, with Direct Numerical Simulation (LBM-DNS) or Large Eddy Simulation (LBM-LES) approaches (e.g.…”

Section: Introductionmentioning

confidence: 99%

Hermite regularization of the lattice Boltzmann method for open source computational aeroacoustics

Brogi

Malaspinas

Chopard

et al. 2017

The Journal of the Acoustical Society of America

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The lattice Boltzmann method (LBM) is emerging as a powerful engineering tool for aeroacoustic computations. However, the LBM has been shown to present accuracy and stability issues in the medium-low Mach number range, which is of interest for aeroacoustic applications. Several solutions have been proposed but are often too computationally expensive, do not retain the simplicity and the advantages typical of the LBM, or are not described well enough to be usable by the community due to proprietary software policies. An original regularized collision operator is proposed, based on the expansion of Hermite polynomials, that greatly improves the accuracy and stability of the LBM without significantly altering its algorithm. The regularized LBM can be easily coupled with both non-reflective boundary conditions and a multi-level grid strategy, essential ingredients for aeroacoustic simulations. Excellent agreement was found between this approach and both experimental and numerical data on two different benchmarks: the laminar, unsteady flow past a 2D cylinder and the 3D turbulent jet. Finally, most of the aeroacoustic computations with LBM have been done with commercial software, while here the entire theoretical framework is implemented using an open source library (PALABOS).

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Section: Introductionmentioning

confidence: 99%

Hermite regularization of the lattice Boltzmann method for open source computational aeroacoustics

Brogi

Malaspinas

Chopard

et al. 2017

The Journal of the Acoustical Society of America

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“…These components occur at the blade passing frequency f bpf = n • z. Additional subharmonic tonal components can occur due to the interaction of the gap flow with the fan blades [8,9,10]. Broadband components can be related to several mechanisms.…”

Section: Introductionmentioning

confidence: 99%

Efficient and Noise Reduced Design of Axial Fans Considering Psychoacoustic Evaluation Criteria

Zenger

Münsterjohann

Becker

2016

AMM

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Axial fans are the largest group of blowers and thus have a significant impact on their environment: Their demand for electrical power and the generation of a significant noise emission, have a negative impact on the environment.In this work the improvement of efficiency and reduction of noise emission are subject of the investigations. Several types of low-pressure axial fans are subject of this investigation. Measurements of pressure rise, efficiency and acoustic behavior will be presented for different blade geometries. The modifications of forward- and backward-skewed blades are compared to a unskewed blade geometry. The forward-skewed configurations show an improvement on the hydraulic properties, the efficiency and reduce the noise emission whilst the backward-skewed configurations improve the acoustic behavior at low flow rates with flow detachment occurring. Besides an acoustic quantification of the noise emission using the sound power level, psychoacoustic methods like loudness and sharpness were used.

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“…They used a Large Eddy Simulation (LES) to compute the unsteady pressure and velocity fields as input data for the acoustic field calculation with an acoustic analogy method. The influence of coherent flow structures in the rotor -stator gap of an axial fan were investigated by Zhu et al (2016) by using a compressible Lattice Boltzmann Method (LBM) in combination with comprehensive experiments to obtain sound pressure data as well as wall pressure data from the blades. The authors were capable to show that several humps in the acoustic spectrum are related to coherent flow structures in the gap.…”

mentioning

confidence: 99%

Investigation of the wall pressure fluctuations, the operational deflection shapes and the airborne noise radiation of a single stage radial pump

Witte¹,

Kranz²,

Torner³

et al. 2019

European Conference on Turbomachinery Fluid Dynamics and Hermodynamics

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The emission of hydro acoustic and airborne noise is a crucial aspect for pump applications in building equipment systems. Hydrodynamic pressure fluctuations inside the pump are the source for the noise emission. These fluctuations propagate far into the connected pipe system as hydro acoustic pressure waves. Furthermore, they will excite structural vibrations of the pump housing causing the emission of airborne noise in the vicinity. The experimental determination of the wall pressure fluctuations, the operational deflection shapes (ODS) as well the airborne noise emissions are one part of this study. The main part of this study will focus on the development and test of a new software framework combining a scale resolving flow simulation and finite element simulation for the numerically prediction of the ODS. The comparison of the computed ODS with the experiment at the 1 th and 2 th order of the blade passing frequency confirmed a good accordance.

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Rotating Coherent Flow Structures as a Source for Narrowband Tip Clearance Noise from Axial Fan

Cited by 6 publications

References 26 publications

Hermite regularization of the lattice Boltzmann method for open source computational aeroacoustics

Hermite regularization of the lattice Boltzmann method for open source computational aeroacoustics

Efficient and Noise Reduced Design of Axial Fans Considering Psychoacoustic Evaluation Criteria

Investigation of the wall pressure fluctuations, the operational deflection shapes and the airborne noise radiation of a single stage radial pump

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