• Title, Summary, Keyword: 원심팬

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A Study on Vibration Reduction of fan in wall-mounted air conditioner (벽걸이 에어컨의 팬 진동 저감에 관한 연구)

  • Chung, Jin-tai;Kim, Min-sung;Lim, Jong-hyuk
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.245-246
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    • 2014
  • 에어컨의 실내기에서 발생하는 소음은 주로 회전하는 팬의 진동에 의하여 발생하게 된다. 이는 구조기인 소음으로 낮은 주파수특성을 갖고, 흡음이나 차음의 소음저감방법으로는 해결하기 어려운 특성을 가지고 있다. 본 연구에서는 벽걸이형 에어컨 원심팬에 발생하는 진동(sway motion)의 원인을 진동실험과 동역학 시뮬레이션을 통하여 규명하였다. 실험적인 측면으로는 시스템분석과 시그널분석을 통하여 원심팬 구성품의 물성치 및 동특성을 확보하였고, 해석적인측면으로는 실험으로 확보된 원심팬의 동특성을 바탕으로 동역학 시뮬레이션 모델을 수립하였다. 실험 및 동역학 시뮬레이션을 바탕으로 원심팬 진동의 원인을 규명하였고, 원심팬 진동의 원인은 원심팬과 모터축사이의 축정렬 불량임을 확인하였다. 이를 해결하고 진동을 저감하기위한 장치를 고안하고 실험을 통하여 진동저감효과를 확인하였다.

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Analysis of Relative Contributions of Tonal Noise Sources in Volute Tongue Region of a Centrifugal Fan (원심팬 볼루트 영역내 순음 소음원의 상대적 기여도 분석)

  • Heo, Seung;Kim, Daehwan;Cheong, Cheolung
    • The Journal of the Acoustical Society of Korea
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    • v.33 no.1
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    • pp.40-47
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    • 2014
  • Interaction between the unsteady flow emitted from the blade of the centrifugal fan and the volute tongue region of fan duct is known as the main noise source of the centrifugal fan. In this paper, the relative contributions of the volute tongue region of the centrifugal fan is analyzed to utilize as the foundation data of low noise design. The internal hybrid CAA (Computational Aero-Acoustics) method is used to predict noise radiated from the main noise source. This method is the noise prediction technique using CFD (Computational Fluid Dynamics), Acoustic analogy, and BEM(Boundary Element Method). The relative contributions of the centrifugal fan volute tongue region using the hybrid CAA method show that the region between the cut-off and the scroll has high contribution than the region between the cut-off and the outlet and the hub region of blade has high contribution than the shroud region of blade. These results is utilized as the important data for the development of low noise centrifugal fan.

Broadband Noise Prediction of the Ice-maker Centrifugal Fan in a Refrigerator Using Hybrid CAA Method and FRPM Technique (복합 CAA 방법과 FRPM 기법을 이용한 냉장고 얼음제조용 원심팬의 광대역 소음 예측)

  • Heo, Seung;Kim, Dae-Hwan;Cheong, Cheol-Ung
    • The Journal of the Acoustical Society of Korea
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    • v.31 no.6
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    • pp.391-398
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    • 2012
  • In this paper, prediction of centrifugal fan was conducted through combination the hybrid CAA method which was used to predict the fan noise with the FRPM technique which was used to generate the broadband noise source. Firstly, flow field surround the centrifugal fan was computed using the RANS equations and noise source region was deducted from the computed flow field. Then the FRPM technique was applied to the source region for generation of turbulence which satisfies the stochastic features. The noise source of the centrifugal fan was modeled by applying the acoustic analogy to the synthesized flow field from the computed and generated flow fields. Finally, the broadband noise of the centrifugal fan was predicted through combination the modeled noise source with the linear propagation which was realized using the boundary element method. It was confirmed that the proposed technique is efficient to predict the tonal and broadband noises of centrifugal fan through comparison with the measured data.

An Analysis of the Acoustic Field in a Closed Structure by a Centrifugal Fan (원심팬에 의한 닫힌 구조물 내부의 음향장 해석)

  • 전완호;이덕주
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.602-607
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    • 1997
  • 원심팬의 소음해석 기법은 Lighthill 방정식을 풀어야 하는 어려운 작업이기 때문에 아직 해석된 예가 드물다. 그래서 본 연구에서는 이미 개발한 움직이는 쌍극에 의한 소음 계산 기법을 이용해서 원심팬의 소음을 자유공간에서 계산한다. 닫힌 공간내의 음장은 경계요소법 혹은 유한요소법으로 많이 연구가 되어 왔다. 본 연구도 일반적으로 많이 사용되는 경계요소법을 이용한다. 이 세가지 방법은 원심팬에 의한 유동/음원 특성을 계산하고, 계산된 음원특성을 이용해서 경계요소법으로 전체 음향장을 계산하는 순서로 수행된다.

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An Analysis of Flow and Noise for Vacuum Cleaner Centrifugal Fan (진공청소기 원심팬의 유동과 소음 해석)

  • 전완호;이덕주;유기완
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.130-135
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    • 1995
  • 본 연구에서는 30000rpm으로 회전하는 진공청소기 원심팬의 유동장을 임펠러, 디퓨저, 케이싱을 모두 고려하여 해석하였다. 또한 삼차원으로 배출되는 출구를 간단한 sink 패널로 모델하여 출구의 효과를 충분히 고려하였다. 해석된 유동장 자료를 이용하여 먼 거리에서의 음압을 예측하였다. 예측된 음압자료는 FFT를 이용하여 측정된 값과 주파수 영역에서 비교하였다. 또한 진공청소기 원심팬의 측정자료에서 보이는 광역소음특성이 임펠러에서 흘려지는 후류와류의 교란에 의한 임펠러와 디퓨저 깃의 비정상 힘이 주된 원인임을 밝혔다.

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Performance/Noise Optimization of Centrifugal Fan Using Response Surface Method (반응표면법을 이용한 원심팬 성능/소음 최적화)

  • Shin, Donghui;Heo, Seung;Cheong, Cheolung;Kim, Tae-Hoon;Jung, Jiwon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.41 no.3
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    • pp.165-172
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    • 2017
  • In this study, centrifugal fan blades used to circulate cold air inside a household refrigerator were optimized to achieve high performance and low noise by using the response surface method, which is frequently employed as an optimization algorithm when multiple independent variables affect one dependent variable. The inlet and outlet blade angles, and the inner radius, were selected as the independent variables. First, the fan blades were optimized to achieve the maximum volume flow rate. Based on this result, a prototype fan blade was manufactured using a 3-D printer. The measured P-Q curves confirmed the increased volume flow rate of the proposed fan. Then, the rotation speed of the new fan was decreased to match the P-Q curve of the existing fan. It was found that a noise reduction of 1.7 dBA could be achieved using the new fan at the same volume flow rate.

Blade shape optimization of centrifugal fan for improving performance and reducing aerodynamic noise of clothes dryer (의류 건조기 성능 향상과 공력소음 저감을 위한 원심팬의 날개 형상 최적화)

  • Choi, Jinho;Ryu, Seo-Yoon;Cheong, Cheolung;Kim, Min-kyu;Lee, Kwangho
    • The Journal of the Acoustical Society of Korea
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    • v.38 no.3
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    • pp.321-327
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    • 2019
  • The purpose of this study is paper is to improve the flow performance and to reduce the aerodynamic noise of air discharge system consisting of a centrifugal fan, ducts and a housing for the clothes dryer. Using computational fluid dynamics and acoustic analogy based on FW-H (Ffowcs-Williams and Hawkings) Eq., air flow field and acoustic fields of the air discharge system are investigated. To optimize aerodynamic performance and aerodynamic noise, the response surface method is employed. The two factors central composite design using the inflow and outflow angles of fan blades is adopted. The devised optimum design shows the reduction of turbulent kinetic energy in the ducts and the housing of the system, and as a result, the improved flow rate and reduce noise is confirmed. Finally, the experment using the proto-type manufactured usign the optimum design shows the increase of flow rate by 4.2 %.

Efficient Prediction of Broadband Noise of a Centrifugal Fan Using U-FRPM Technique (U-FRPM 기법을 이용한 원심팬 광대역소음의 효율적 예측)

  • Heo, Seung;Cheong, Chulung
    • The Journal of the Acoustical Society of Korea
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    • v.34 no.1
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    • pp.36-45
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    • 2015
  • Recently, a lot of studies have been made about the methods used to generate turbulent velocity fields stochastically in order to effectively predict broadband flow noise. Among them, the FRPM (Fast Random Particle Mesh) method which generates turbulence with specific statistical properties using turbulence kinetic energy and dissipation obtained from the steady solution of the RANS (Reynolds Averaged Navier-Stokes) equations has been successfully applied. However, the FRPM method cannot be applied to the flow noise problems involving intrinsic unsteady characteristics such as centrifugal fan. In this paper, to effectively predict the broadband noise generated by centrifugal fan, U-FRPM (unsteady FRPM) method is developed by extending the FRPM method to be combined with the unsteady numerical solutions of the unsteady RANS equations to generate the turbulence considered as broadband noise sources. Firstly, an unsteady flow field is obtained from the unsteady RANS equations through CFD (Computational Fluid Dynamics). Then, noise sources are generated using the U-FRPM method combined with acoustic analogy. Finally, the linear propagation model which is realized through BEM (Boundary Element Method) is combined with the generated sources to predict broadband noise at the listeners' position. The proposed technique is validated to compare its prediction result with the measured data.