The Journal of the Acoustical Society of Korea (한국음향학회지)

The Acoustical Society of Korea (한국음향학회)
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Improvement in flow and noise performance of backward centrifugal fan by redesigning airfoil geometry

익형 형상 재설계를 통한 후향익 원심팬의 유동 및 소음성능 개선

  • Received : 2021.08.20
  • Accepted : 2021.10.16
  • Published : 2021.11.30
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Abstract

The goal of this study is to improve flow and noise performances of existing backward-curved blade centrifugal fan system used for circulating cold air in a refrigerator freezer by optimally designing airfoil shape. The unique characteristics of the system is to drive cold airflow with two volute tongues in combination with duct system in a back side of a refrigerator without scroll housing generally used in a typical centrifugal fan system. First, flow and noise performances of existing fan system were evaluated experimentally. A P-Q curve was obtained using a fan performance tester in the flow experiment, and noise spectrum was measured in an anechoic chamber in the noise experiment. Then, flow characteristics were numerically analyzed by solving the three-dimensional unsteady Navier-Stokes equations and noise analysis was performed by solving the Ffowcs Williams and Hawkins equation with input from the flow simulation results. The validity of numerical results was confirmed by comparing them with the measured ones. Based on the verified numerical method, blade inlet and outlet angles were optimized for maximum flow rate using the two-factor central composite design of the response surface method. Finally, the flow and noise performances of a prototype manufactured with the optimum design were experimentally evaluated, which showed the improvement in flow and noise performance.

본 연구의 목표는 냉장고 냉동실 냉기순환용으로 사용되는 후향익 원심팬 시스템을 대상으로 익형의 형상을 최적설계 하여 유동성능 및 소음성능을 향상시키는 것이다. 대상 시스템은 전형적인 원심팬 시스템에서 사용되는 스크롤 하우징 형상 없이 두 개의 Volute가 후면 덕트 시스템과 연계하여 냉기를 공급한다는 특성을 가지고 있다. 먼저 팬 시스템의 유동 및 소음성능을 실험적으로 평가하였다. 유동실험에서 팬 성능 시험기를 사용하여 P-Q 곡선을 도출할 수 있었으며, 무향실에서 소음실험을 통해 소음 스펙트럼을 측정하였다. 다음으로, 3차원 비정상 Navier-Stokes 방정식을 전산유체역학을 사용하여 수치해석하여 유동 특성을 분석하였으며, 예측한 유동장을 입력값으로 Ffowcs Willams-Hawkings방정식을 이용해 소음해석을 수행하였다. 수치해석결과는 실험 결과와 비교를 통해 그 유효성을 검증하였다. 검증된 수치해석 기법을 기반으로 반응표면법의 2인자 중심합성법을 통해 유량이 최대가 되는 입구각 및 출구각을 도출하였다. 마지막으로 최적화된 팬을 대상으로 시제품을 제작하여 실험한 결과 개선된 유량 성능 및 소음성능을 확인하였다.

Keywords

Acknowledgement

본 연구는 산업통상자원부가 지원하는 조선해양산업핵심기술개발사업(20012974)으로 수행된 연구결과임.

References

  1. M. Shin, C. Cheong, T. H. Kim, and J. Koo, "Numerical and experimental investigation on improvement of flow and noise performances of ice-fan flow piping system of household refrigerator" (in Korean), Trans. Korean Soc. Noise Vib. Eng. 28, 694-700 (2018). https://doi.org/10.5050/KSNVE.2018.28.6.694
  2. D. Shin, S. Y. Ryu, C. Cheong, T. H. Kim, and J. Jung, "Development of high-performance /low-noise centrifugal fan circulating cold air inside a household refrigerator by reduction of vortex flow" (in Korean), Trans. Korean Soc. Noise Vib. Eng. 26, 428-435 (2016). https://doi.org/10.5050/KSNVE.2016.26.4.428
  3. S. Heo, C. Cheong, and T. H. Kim, "Development of low-noise centrifugal fans for a refrigerator using inclined S-shaped trailing edge," IJR. 34, 2076-2091 (2011).
  4. D. Shin, H. Heo, C. Cheong, T. Kim, and J. Jung, "Performance-noise optimization of centrifugal fan using response surface method" (in Korean), Trans. Korean Soc. Mech. Eng. A, 41, 165-172 (2017). https://doi.org/10.3795/KSME-A.2017.41.3.165
  5. J. Choi, S. Y. Ryu, C. Cheong, M. K. Kim, and K. Lee, "Blade shape optimization of centrifugal fan for improving performance and reducing aerodynamic noise of clothes dryer" (in Korean), J. Acoust. Soc. Kr. 38, 321-327 (2019).
  6. K. Kim, S. Y. Ryu, C. Cheong, S. Seo, and C. Jang, "Optimal design of impeller in fan motor unit of cordless vacuum cleaner for improving flow performance andreducing aerodynamic noise" (in Korean), J. Acoust. Soc. Kr. 39, 379-389 (2020).
  7. B. Lee, W. Sim, J. Chung, and J. Jo, "Reduction of flow-induced noise in a household air purifier," JMST. 34, 3105-3115 (2020).
  8. H. Seung, K. Daehwan, C. Cheolung, and K. T.-H. K, "Prediction of internal broadband noise of a centrifugal fan using stochastic turbulent synthetic model" (in Korean), Trans. Korean Soc. Noise Vib. Eng. 21, 1138-1145 (2011). https://doi.org/10.5050/KSNVE.2011.21.12.1138
  9. H. Seung, K. Daehwan, and C. Cheolung, "Broadband noise prediction of the ice-maker centrifugal fan in a refrigerator using hybrid CAA method and FRPM technique" (in Korean), J. Acoust. Soc. Kr. 31, 391-398 (2012). https://doi.org/10.7776/ASK.2012.31.6.391
  10. H. Seung and C. Cheolung, "Efficient prediction of broadband noise of a centrifugal fan using u-frpm technique" (in Korean), J. Acoust. Soc. Kr. 34, 36-45 (2015). https://doi.org/10.7776/ASK.2015.34.1.036