• Title/Summary/Keyword: Turbo-fan noise

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Study on the Optimal Shape of Low Noise, New Concept Fan for Refrigerator (냉장고용 저소음 신형상홴의 최적 형상에 관한 연구)

  • 정용규;김창준;백승조;전완호
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.05a
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    • pp.645-650
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    • 2002
  • In this paper, new concept, low noise axial fan was developed. The fan was designed to operate at high-pressure condition inside the refrigerator. This fan - we call it Alpha fan - has small turbo blades at trailing edge of axial fan. These turbo blades make alpha fan operate at high pressure and low noise condition. In order to find out the optimal value of design parameters, 6-sigma method was used. The design parameters are ratio between inner and outer diameter, Height, Install angle and Install position of turbo blade. Optimal value of turbo blade was found out and the noise generated from this fan is reduced about 3dB(A).

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Noise Reduction of Turbo Fans for Air-Conditioner Indoor Units (에어컨 실내기 터보팬의 소음 저감)

  • 김진백;최원석;구형모;이재권
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.93-96
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    • 2004
  • A turbo-fan for the 4-way cassette indoor units of air-conditioners has been investigated. The main purpose of this investigation is the reduction of the turbo-fan noise. In order to reduce the noise level, many design parameters of turbo-fans such as blade section, blade thickness, geometry of blade leading edge, blade width, blade angle and bellmouth depth have been studied. With the experimental data of these parameters, a new turbo-fan was made for our system. The noise level of the new system was at least 3 dB(A) lower than that of the current in use.

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The Study on Vibration Isolation of Industrial Turbo-fan (산업용 터보팬의 진동절연에 관한 연구)

  • Park, Ik-Pil;Kim, Dong-Young;Kwon, Yong-Soo;Ahn, Chan-Woo
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.609-615
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    • 2001
  • A turbo-fan is easily exposed to noise and vibration as against other industrial machines and the majority of them is subject to be damaged by vibration. The most usual problem of vibration in a turbo-fan is resonance so the case of being composed of iron sheet structure with low strength like a turbo-fan should be taken seriously. In this paper, FFT(Fast Fourier Transform) and Order tracking method were used to analyze factors of vibration in a turbo-fan and hereby with proper selection of vibration isolator, we wanted to reduce vibration of base. After Order tracking, we knew resonance occurred in rotational frequency 23 Hz(1400 rpm) at the casing and the bearing. After the test of base vibration using vibration isolators, the spring isolator was more effective than the robber isolator in the base vibration and the vibration isolating is more effective in the case that the isolating pad is adhered to the bottom of the isolating spring.

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Development of Standard Series for Turbo Blowers (터보 블로워 표준화 제품 개발 사례)

  • Song, Kween;Kim, Kwang-Ho;Kim, Shin Hyoung;Kim, Hwe-Ryong
    • 유체기계공업학회:학술대회논문집
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    • 2000.12a
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    • pp.99-103
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    • 2000
  • This paper describes the development of standard series for turbo blowers. In mass production system, it is very required to standardize blowers to improve the productivity of ordering, estimating, manufacturing. To standardize blowers, we performed researches on the effects of $b_1$(impeller inlet width), $b_2$(impeller outlet width), ${\beta}_1$(blade inlet angle), ${\beta}_2$(blade outlet angle), Z(number of blades) of impellers and geometry of casing experimentally. Through this study, we chose the several best model of turbo blowers with high efficiency and low noise, which represent each specific speed series 63, 80, 100, 125, 160, 200, 250, 315. After the development of such standardized blowers, the test results are used to prepare the fan geometry and performance database for a selection software.

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Flow Analysis of a Low-Noise Turbo Fan for a Vacuum Cleaner (진공청소기용 저소음 터보팬 내부 유동 해석)

  • Lee, Ki-Choon;Kim, Chang-Jun;Hur, Nahmkeon;Jeon, Wan-Ho
    • The KSFM Journal of Fluid Machinery
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    • v.6 no.4 s.21
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    • pp.14-20
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    • 2003
  • In this study an analysis of the flow characteristics in three types of turbo-fans for a vacuum cleaner was performed by using CFD. The characteristics of three models calculated for various rotating speed for flow rates are obtained and compared with measured data. The mixing plane approach is applied to compute the flow between impeller and diffuser. The results show that the model that is modified to reduce fan noise gives stable flow characteristics in operating range than the original model, with both models show similar performance characteristics at the range of high flow rate. Since in the modified model it takes much longer for an impeller blade to pass a diffuser blade than in the original model, and the peak pressure at BPF can be relieved, it is anticipated that the modified model give much lower noise level with similar performance than the original one, which remains to be verified by unsteady computation and measurements. The good agreement between the predictions and measurement results confirms the validity of this study.

Flow Analysis of a Low-Noise Turbo Fan for a Vacuum Cleaner (진공청소기용 저소음 터보팬 내부 유동 특성 해석)

  • Lee Ki-Choon;Kim Chang Jun;Hur Nahmkeon;Jeon Wan Ho
    • Proceedings of the KSME Conference
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    • 2002.08a
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    • pp.631-634
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    • 2002
  • The study of the flow characteristics in two types of turbo-fans for a vacuum cleaner was performed in a previous study. In present study an analysis of a new modified model to reduce fan noise was performed by using CFD. The characteristics of three models calculated for various rotating speeds and flow rates are obtained and compared with available measured data. The results show that the modified model gives stable flow characteristics in operating range than the original model, while both models show similar performance characteristics at the range of high flow rate. Since in the modified model it takes much longer for an impeller blade to pass a diffuser blade than in the original model, and thus the peak pressure at BPF can be relieved, it is anticipated that the modified model gives much lower noise level with similar performance than the original one, which remains to be verified by unsteady computation and measurements.

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A Study on the Identification of Aeroacoustic Noise and Noise Reduction for a Vacuum Cleaner (청소기의 공력소음 특성 파악 및 저소음화에 관한 연구)

  • 전완호;백승조;김창준
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.13 no.6
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    • pp.460-466
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    • 2003
  • The aeroacoustic characteristics and noise reduction method of a centrifugal fan for a bagless vacuum cleaner were studied. The major noise source of vacuum cleaner is the centrifugal fan. The impeller of the fan rotates over 30000 rpm and generates very high-level piercing noise. It was found that the dominant noise source of the fan is generated from the aerodynamic interaction between the highly rotating impeller and stationary diffuser. In order to reduce the high tonal sound generated from the aerodynamic interaction between the impeller and diffuser, tapered impeller was carefully designed and tested. The trailing edge of the tapered impeller was inclined and this reduces the flow interactions between the rotating impeller and the stationary diffuser because of some phase shift. The static efficiency of the new impeller is slightly lower than the conventional one. The overall SPL is reduced about 3.6 dBA. The SPL of blade passing frequency(BPF) is reduced about 6 dBA and the $2^{nd}$ BPF is reduced about 20 dBA. The vacuum cleaner with the tapered impeller has lower noise level than that of the previous impeller and the strong tonal sound was dramatically reduced.

The Analysis of the Unsteady Flow Field and Aerodynamic Sound of Fan Motor in a Vacuum Cleaner (진공청소기용 팬 모터의 비정상 유동 해석 및 공력소음 해석)

  • 김재열;심재기;송경석;오성민;양동조;김우진
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2004.04a
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    • pp.281-286
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    • 2004
  • The vacuum cleaner motor runs on very high speed for the suction power. Specially, the motive power is provided by the impeller being rotate on very high speed. And centrifugal fan consists of the impeller, the diffuser, and the circular casing. Due to the high rotating speed or the impeller and small gap distance between the impeller and diffuser, the centrifugal fan makes very high noise level at BPF and harmonic frequencies. In order to calculate the sound pressure of centrifugal fan, the unsteady flow data is needed. And Noise cause is dividing to fluid noise by exhaust flow of fan and vibration noise by rotational vibration of vacuum cleaner fan motor. Until now, measuring method has been used to measure vibration by the accelerometer; this method has been not measured for the vibration in some parts of brush and commutator because of motor construction and 3-D vibrating mode. This paper was purposed on the accurate analysis, using laser vibration analyzer,. By using this measured data of noise cause against the difficult part in old times, we would like to use for the design of silent fan motor.

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Anallysis of the flow and noise characteristics of small turbo fan in a ultra slim note PC (초박형 노트북 냉각 터보팬의 유동 및 소음 분석)

  • Jeon, W.H.;Lim, T.G.;Minorkkawa, Gaku;Miyahara, Masaharu
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2013.10a
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    • pp.775-780
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    • 2013
  • In recent years, a notebook like an ultrabook gets thinner. Its thickness causes problems in cooling fan performance, system installation condition, and so on. In this study, we installed a small turbofan in notebook system with very narrow gap in order to generate similar condition to a real product. Experiments were performed to measure the fan's performance and the flow and noise characteristics, its results were compared with computational ones. Prediction of P-Q curve using CFD showed under about 5% error in high flow rate and its trend was agreed with experimental one over the flow field. Experimental data to measure the noise at a distance of 100 mm from a rotation axis direction of an impeller corresponded well with computational ones of broadband and BPF noise. The noise experiments to measure at a distance of 100 mm from a rotation axis direction of an impeller corresponded well with computational ones of broadband and BPF noise. Especially, tip part of impeller blade and part of exit and bottom near in an analysis by a commercial program(FlowNoise).

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Study on the Noise Characteristic of Centrifugal Fan operating at High Pressure Region (흡입저항이 높은 원심홴 소음특성에 관한 연구)

  • Jung, Yeun-Young;Park, Jin-Won;Jeon, Wan-Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.05a
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    • pp.1011-1014
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    • 2006
  • Turbo blower generates high peaks when it operates at high pressure region. The fan of the air-cleaner system, operates especially high pressure region due to several filters, generates high noise level. In this case, the tonal sound of BPF makes people annoyance. The blower of air-cleaner has several high resistance filters in its inlet area and rotates above 900rpm Moreover, for the compact design, the size of the blower should be reduced 10%. The reduced diameter of blower makes low flow rate and high noise level. In order to reduce the noise, new blade shape was suggested and optimized

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