DOI QR코드

DOI QR Code

Aeroacoustics Analysis and Noise Reduction of Dual Type Combined Fan using Lattice-Boltzmann Method

Lattice-Boltzmann Method를 이용한 이중구조팬의 공력소음 해석 및 저감

  • Kim, Wootaek (Department of Mechanical Engineering, Hanyang University) ;
  • Ryu, Minhyung (Department of Mechanical Engineering, Hanyang University) ;
  • Kim, Jinwook (Department of Mechanical Engineering, Hanyang University) ;
  • Ho, Sunghwan (EXA Korea Corporation) ;
  • Cho, Leesang (Department of Mechanical & System Engineering, Hansung University) ;
  • Cho, Jinsoo (School of Mechanical Engineering, Hanyang University)
  • Received : 2016.01.16
  • Accepted : 2016.04.18
  • Published : 2016.05.01

Abstract

In this study, aeroacoustic characteristics of combined fan are investigated and noise was reduced by applying Serrated Trailing Edge which is known as the method to reduce fan noises. Unsteady CFD (Computational Fluid Dynamics) analysis was carried out using Lattice Boltzmann Method(LBM) to figure out the combined fan's aeroacoustics and experimental results was used to verify simulation results. Results show that different BPFs are generated at the each inner fan and outer fan on the different frequency while Blade Passing Frequency(BPF) of general fans is constant on the entire frequency range. Boundary vortex and vortex shedding are suppressed or dispersed by applying the Serrated Trailing Edge to the inner fan. Furthermore, broadband noise and fan's torque are reduced.

본 연구에서는 이중구조팬의 소음특성을 알아보고 소음저감 방법으로 알려진 톱니형 뒷전(Serrated Trailing Egde)을 적용하여 이중구조팬의 소음을 저감시켰다. 해석에는 Lattice Boltzmann Method(LBM)를 이용한 비정상 전산해석을 수행하였으며 해석의 타당성을 평가하기 위하여 시험을 실시하였다. 이중구조팬은 일반적인 팬처럼 단일의 Blade Passing Frequency(BPF)를 갖는 것이 아니라 내부팬과 외부팬 각각의 BPF가 서로 다른 음역대에서 나타나는 것을 확인 하였다. 톱니형 뒷전을 내부팬에 적용하여 경계층에서의 구속와류와 뒷전에서의 와류흘림이 억제 또는 분산되고 광역소음뿐만 아니라 팬의 토크도 저감되었다.

Keywords

References

  1. T. Wright, W.E. Simmons, "Blade Sweep for Low-Speed Axial Fans." Journal of Turbomachinery, 1990, Vol. 112, pp.151-158. https://doi.org/10.1115/1.2927413
  2. T. Fukano, Y. Takamatsu, "The Effects of Tip Clearence on the Noise of Low Pressure Axial and Mixed Flow Fans." Journal of Sound and Vibration, Feb. 1986, pp.291-308.
  3. T.H Kim, S.H. Lee, S.H. Lee "Computation of Seerated Trailing Edge Flow and Noise using a Hybrid Zonal RANS-LES." 2012, KSNVE, Vol. 22, No. 5, pp.444-450. https://doi.org/10.5050/KSNVE.2012.22.5.444
  4. J.S. Kim, H.S. Kim, K.T. Hyun "Development of Uneven Fan by Aeroacoustics Analysis & Optimization Method." 2012 KSCFE, Vol. 17, No. 1, pp.16-22.
  5. H. Inazumi, K. Yano, "Axial Flow Fan." 2000, JP 2000-130396.
  6. G.Q. Liang, J.C. Wang, Y. C, C.H. Zhou, J. L, L.Q. Ren "The Study of Qwl's Silent Flight and Noise Reduction on Fan Vane with Bionic Structure" 2010, Advances in Natural Science, Vol. 3, No. 2, pp. 192-198.
  7. T. Fukano, Y. Kodama, Y Sensoo, "Noise generated by low pressure axial flow fans : Modeling of the turbulent noise," Journal of Sound and Vibration, Feb. 1977, Vol. 50, pp. 63-74. https://doi.org/10.1016/0022-460X(77)90551-X
  8. Balmuda Korea Inc, "Axial Fan." 2011, 1020117028040.
  9. H.J. Choi, J.C. Park, H.S. Yoon, H.H. Chun, D.H. Kang, "Large Eddy Simulation of Turbulent Flow around a Ship Model Using Message Passing Interface." 2006, KSOE, Vol. 20, No. 4, pp. 76-82.
  10. R.T. Jung "Feasibility study on the two-dimensional free surface simulation using the Lattice-Boltzmann Method." 2012, JKOSMEE, Vol. 15, No. 4, pp. 273-280.
  11. H. Martin, H. Jens, "Implementation of no-site velocity boundary conditions for D3Q19 lattice boltzmann simulations." 2010, Journal of Statistical Mechanics: Theory and Experiment, 10.1088/1742-5468.
  12. P. L. Bhatnagar, E. P. Gross, and M. Krook, "A model for collision processes in gases. I. Small amplitude processes in charged and neutral one-component systems." 1954, Physical Review, vol. 94, no. 3, pp. 511-525. https://doi.org/10.1103/PhysRev.94.511
  13. Y. H. Qian, D. D'Humieres and P. Lallemand, "Lattice BGK models for Navier Stokes equation." 1992, Europhys Letters, Vol. 17, No. 6, pp. 479-484. https://doi.org/10.1209/0295-5075/17/6/001
  14. M.J. Lighthill, "On Sound Generated Aerodynamically." 1952, Proceedings of the Royal Society of London, Series A: Mathematical and Physical Sciences, Vol. 211, No. 1107, pp. 564-587. https://doi.org/10.1098/rspa.1952.0060
  15. J.E. Ffowcs Williams, D.L. Hawkings, 1969, "Theory Relating to the Noise of Rotating Machinery" 1969, Journal of Sound and Vibration, Vol. 10, No. 1, pp. 10-21. https://doi.org/10.1016/0022-460X(69)90125-4
  16. Y.H. Yu, S.N. Jung, "Prediction of Thickness and Loading Noise of Hovering Model Helicopter Rotor." Nov. 2014, KSAS Conference, 1767-1770.
  17. F. Farassat, "Linear Acoustic Formulas for Calculation of Rotating Blade Noise." 1981, AIAA J. Vol. 19, No. 9, pp. 1122. https://doi.org/10.2514/3.60051
  18. Korean Industrial Standards "Method of A-Weighted Sound Pressure Level Measurement for Fans, Blowers and Compressors." 1999, KS B 6311.
  19. Korean Industrial Standards "Testing Methods for Industrial Fans" 2001, KS B 6311.
  20. T. Zhu, S. Michael, T.H. Carolus, B. Neuhierl, F. Perot, "Experimental and Numerical Investigation of Tip Clearance Noise of an Axial Fan Using a Lattice Boltzmann Method." 2014, ICSV Conference, Beijing, China.
  21. F. Perot, M.S. Kim, S. Moreau, M. Henner, D. Neal "Direct Aeroacoustics Perdiction of a Low Speed Axial Fan." 2010, AIAA/CEAS Aeroacoustics Conference, Reston, Virginia.
  22. C. Lee "A Prediction method for the aerodynamic performance and the noise of axial flow fan." 1997, SAREK Conference.