한국음향학회지 (The Journal of the Acoustical Society of Korea)

  • 제34권1호
  • /
  • Pages.36-45
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  • 2015
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  • 1225-4428(pISSN)
  • /
  • 2287-3775(eISSN)
한국음향학회 (The Acoustical Society of Korea)
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U-FRPM 기법을 이용한 원심팬 광대역소음의 효율적 예측

Efficient Prediction of Broadband Noise of a Centrifugal Fan Using U-FRPM Technique

  • 허승 (부산대학교 기계공학부) ;
  • 정철웅 (부산대학교 기계공학부)
  • Heo, Seung (School of Mechanical Engineering, Pusan National University) ;
  • Cheong, Chulung (School of Mechanical Engineering, Pusan National University)
  • 투고 : 2014.08.07
  • 심사 : 2014.12.24
  • 발행 : 2015.01.31
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초록

유동광대역소음을 효율적으로 예측하기 위하여 통계적으로 난류를 재생하는 방법에 대한 많은 연구들이 최근에 진행되고 있다. 그 중에서도, FRPM(Fast Random Particle Mesh) 기법은 RANS(Reynolds-Averaged Navier-Stokes) 방정식 해석을 통해 도출된 정상상태 유동장의 난류 운동에너지와 소산 값을 이용하여 특정한 통계적 특성을 가지는 난류를 재생하는 기법으로서 유동광대역소음 문제 등에 성공적인 적용 예에 대해서 보고되고 있다. 하지만 기존의 FRPM 방법은 축류팬과 같이 축 대칭 특성을 갖는 기계의 경우 정상상태의 유동장을 기초로 광대역소음을 예측하는 문제에는 적용할 수 있으나, 원심팬과 같이 볼루트 영역으로 인하여 축 대칭이 성립되지 않는 기계류의 유동광대역소음에는 적용할 수 없다. 본 연구에서는 이러한 FRPM 기법을 확장하여, 원심팬에서 발생하는 광대역소음을 효율적으로 예측하기 위하여 비정상 RANS 방정식의 수치해와 연계하여 광대역소음원으로 고려되는 난류를 특정한 통계적 특성을 가지도록 재생할 수 있는 U-FRPM(Unsteady-FRPM) 기법을 제안하였다. 먼저 전산유체역학을 사용하여 RANS 방정식을 해석함으로써, 원심팬 주위의 비정상상태 유동장 정보를 도출하고, 음향상사법(Acoustic Analogy)을 기초로 도출된 유동소음원을 U-FRPM을 이용하여 모델링하였다. 모델링된 소음원은 경계요소법을 통해 구현되는 선형음향전파모델과 연계하여 수음점에서 광대역소음을 예측하는데 이용되었다. 예측된 결과와 실험결과의 비교를 통해 본 논문에서 제시한 방법의 유효성을 확인하였다.

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.

키워드

참고문헌

  1. M. Tournour, Z. El Hachemi, A. Read, F. Mendonca, F. Barone, and P. Durello, "Investigation of the tonal noise radiated by subsonic fans using the aero-acoustic analogy," Fan Noise Conference 2003, Senlis, France.
  2. S. Lee, S. Heo, and C. Cheong, "Prediction and reduction of internal blade-passing frequency noise of the centrifugal fan in a refrigerator," Int. J. Refrig. 33, 1129-1141 (2010). https://doi.org/10.1016/j.ijrefrig.2010.03.006
  3. S. Heo, C. Cheong, and T.-H. Kim, "Development of low noise centrifugal fan a refrigerator using inclined S-shaped trailing edge," Int. J. Refrig. 34, 2049-2091 (2011).
  4. S. Heo, D. Kim, and C. Cheong, "Analysis of relative contributions of tonal noise sources in volute tongue region of a centrifugal fan" (in Korean), J. Acoust. Soc. Kr. 33, 40-47 (2014). https://doi.org/10.7776/ASK.2014.33.1.040
  5. S. Heo, D. Kim, C. Cheong, and T.-H. Kim, "Prediction of internal broadband noise of a centrifugal fan using stochastic turbulent synthetic model" (in Korean), Trans. KSNEV. 21, 1138-1145 (2011). https://doi.org/10.5050/KSNVE.2011.21.12.1138
  6. W. Béchara, C. Bailly, and P. Lafon, "Stochastic approach to noise modeling for free turbulent flows," AIAA J. 31, 445-463, (1994).
  7. C. Bailly, P. Lafon, and S. Candel, "Computation of noise generation and propagation for free and confined turbulent flow," AIAA Conference, 96-1732 (1996).
  8. S. Heo, D. Kim, and C. Cheong, "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
  9. R. Ewert, J. Dierke, J. Siebert, A. Appel, M. Siefert, and O. Kornow, "CAA broadband noise prediction for aeroacoustic design," J. Sound Vib, 330, 4139-4160 (2011). https://doi.org/10.1016/j.jsv.2011.04.014
  10. J. Ryu, C. Cheong, S. Kim, and S. Lee, "Computation of internal aerodynamic noise from a quick-opening throttle valve using frequency-domain acoustic analogy," Appl. Acoust. 66, 1278-1308 (2005). https://doi.org/10.1016/j.apacoust.2005.04.002
  11. M. J. Lighthill, "On sound generated aerodynamically, I. general theory," Proc. Roy. Soc. 211A, 564-587 (1952).
  12. N. Curle, "The influence of solid boundaries on aerodynamic sound," Proc. Roy. Soc. 231A, 505-514 (1955).
  13. S. Velarde-Suarez, R. Ballesteros-Tajadura, J. P. Hurtado- Cruz, and C. Santolaria-Morros, "Experimental determination of the tonal noise sources in a centrifugal fan," J. Sound Vib. 295, 781-796 (2006) https://doi.org/10.1016/j.jsv.2006.01.049
  14. C. Cheong, P. Joseph, Y. Park, and S. Lee, "Computational on aeolian tone from a circular cylinder using source models," Appl. Acoust. 69, 110-236 (2008). https://doi.org/10.1016/j.apacoust.2006.10.004
  15. M. Dieste, G. Gabard, "Random-vortex-particle methods for broadband fan interaction noise," AIAA 2010 Conference
  16. D. Russell, J. Titlow, and Y. Bemmen, "Acoustic monopoles, dipoles, and quadrupoles: An experiment revisited," Am. J. Phys. 67, 660-664 (1999).

피인용 문헌

  1. Development of High-performance/low-noise Centrifugal Fan Circulating Cold Air Inside a Household Refrigerator by Reduction of Vortex Flow vol.26, pp.4, 2016, https://doi.org/10.5050/KSNVE.2016.26.4.428