Minimizing the Trailing Edge Noise From Rotor-Only Axial Fans Using Design Optimization

Sørensen, Dan

doi:10.1006/jsvi.2001.3735

Cited by 9 publications

(4 citation statements)

References 19 publications

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“…Akaike et al [3] addressed noise reduction of ac ooling (propeller)f an for an automobile radiator by optimizing the axial distance between the fanr otor and the shroud using three-dimensional numerical simulations and exper- imental measurements. Sorensen [4] conducted numerical design optimization to minimize trailing edge noise of rotor-only axial fans. Maaloum et al [5] evaluated the aeroacoustic performance of axial-flowf ans using an aeroacoustic approach based on the vortexsurface method, and predicted their tonal noise using the Ffowcs Williams-Hawkings (FW-H) equation.…”

Section: Introductionmentioning

confidence: 99%

Optimum Design for Noise Reduction of a Two-Bladed Propeller Fan

Choi¹,

Lee²,

Chung³

2015

Acta Acustica united with Acustica

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Numerical simulations were performed to investigate the sound generation mechanism of apropeller faninthe outdoor unit of an air conditioner.T he vortexa nd separation flowa round two-and three-bladed propeller fans were analyzed to locate the sources of noise. Atwo-bladed fanusually has alower flowrate than athree-bladed fana tt he same rotating speed. In general, at wo-bladed fans hould increase the rotating speed to obtain the same amount of flowr ate as at hree-bladed fan. The increased rotating speed of at wo-bladed fanm ay results in al ouder noise comparing at hree-bladed fan. To overcome this drawback, an optimized two-bladed fanw as proposed by increasing the solidity and pitch angle. During optimizing the two-bladed fan, the relative priorities of the design parameters were evaluated to identify the most important, and these parameters were then optimized using the response surface methodology.The overall sound pressure level(OASPL)o fthe newoptimized twobladed propeller fanw as 5.2 dB lower than that of previous two-bladed fans and 1.2 dB lower than that of the optimized three-bladed fan. PACS no. 43.28.-g 920 ©S.Hirzel Verlag · EAA Choi et al.:O ptimum design forpropeller fan ACTA ACUSTICA UNITED WITH ACUSTICA

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Section: Introductionmentioning

confidence: 99%

Optimum Design for Noise Reduction of a Two-Bladed Propeller Fan

Choi¹,

Lee²,

Chung³

2015

Acta Acustica united with Acustica

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Section: Introductionmentioning

confidence: 99%

“…14,15 Most scholars only focus on the structural factors that affect the aerodynamic noise of wind blades and the research on the causes of noise. [16][17][18][19] But the location of noise sources and effective solutions is still not deep. Some common theories have been explored, but a few of means and mechanisms do not apply to internal flow characteristics and pressure fluctuation characteristics of the trailing edge of the axial-flow fan blades.…”

Section: Introductionmentioning

confidence: 99%

The influence of axial-flow fan trailing edge structure on internal flow

Zhang

Yuan

Zhou

et al. 2018

Advances in Mechanical Engineering

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Axial-flow fan with advantages such as large air volume, high head pressure, and low noise is commonly used in the work of air-conditioner outdoor unit. In order to investigate the internal flow mechanism of the axial-flow fan with different trailing edge structures of impellers, four kinds of impellers were designed, and numerical simulation and experiment were deployed in this article. The pressure distribution on the blades surface and distribution of vorticity in impellers were obtained using numerical simulation. Distribution of blade loading and velocity at the circumference are discussed. The relationship between the wideband noise and the trailing edge was established based on the experiment results. The results show that after the optimization of the trailing edge structure, the distribution of vorticity near the trailing edge of the blade is more uniform, especially at the trailing edge of 80% of the chord length of the suction surface. From the blade height position of 70% to the impeller tip, the pressure on the surface rapidly increases due to the tip vortex and the vortex shedding on the blade edge occurred in the top region of impeller. The pressure fluctuation amplitude at the trailing edge structure of the tail-edge optimization structure is smaller. In the distribution of blade loading, the three tail-edge optimization structures have smaller pressure fluctuations and pressure differences at the trailing edge structure. It is extremely important to control the fluctuation amplitude at the trailing edge. The amplitude of low-frequency sound pressure level of optimizing the trailing edge structure decreases obviously in the range of 50-125 Hz, and the optimization structure of trailing edge has an obvious effect on low-frequency wideband noise.

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“…He also set a solid foundation for turbomachinery by deriving the relation for energy transfer between the fluid and the impeller. Recently, Sørensen [4] combined a noise prediction model with an aerodynamic model to execute the design optimization on an axial-flow fan. He selected the blade element model to calculate the aerodynamic performance of the fan and, furthermore, provided velocities used in the calculation of the trailing edge noise.…”

Section: Introductionmentioning

confidence: 99%

An integrated performance analysis for a small axial-flow fan

Lin

Tsai

2010

Proceedings of the Institution of Mechanical Engineers, Part C:

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Owing to the high system resistance and space limitations on computer devices, many researchers have begun to pay more attention to developing high-performance axial-flow fans. Evidently, evaluating the fan performance under different operating conditions is essential for both designer and practical engineering applications. However, previous studies do not provide a detailed flow-field analysis, torque prediction, efficiency estimation at various operating points, and qualitative numerical prediction of sound generation. Thus, this comprehensive study was performed with the aim to offer the aforementioned technical information and completely evaluate the fan performance. In this study, computational fluid dynamics (CFD) simulations and experimental measurements are utilized to perform flow visualization, torque calculation, efficiency estimation, and noise analysis. For demonstration purposes, a 120 mm-diameter axial-flow fan is designed and fabricated via computer numerical control (CNC) to serve as the research subject. The result indicates that the P— Q curve and the sound pressure level (SPL) spectrum of the experiment are in agreement with those of numerical simulations. The numerical deviations in maximum volumetric flowrate and static pressure are approximately 7 per cent and 13 per cent, respectively. Regarding the acoustic characteristics, the overall SPLs for measured spectra and large eddy simulation (LES) calculation are 51.3 dB and 48.1 dB, respectively. Consequently, this study establishes an integrated aerodynamic, acoustic, and electro-mechanical evaluation approach that can be used as an important tool for fan designers.

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Minimizing the Trailing Edge Noise From Rotor-Only Axial Fans Using Design Optimization

Cited by 9 publications

References 19 publications

Optimum Design for Noise Reduction of a Two-Bladed Propeller Fan

Optimum Design for Noise Reduction of a Two-Bladed Propeller Fan

The influence of axial-flow fan trailing edge structure on internal flow

An integrated performance analysis for a small axial-flow fan

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