Effect of Blade Loading on the Structure of Tip Leakage Flow in a Forward-Swept Axial-Flow Fan

블레이드 하중이 축류형 팬에서의 팁 누설 유동구조에 미치는 영향

  • Published : 2003.04.01

Abstract

An experimental analysis using three-dimensional laser Doppler velocimetry(LDV) measurement and computational analysis using the Reynolds stress model in FLUENT are conducted to give a clear understanding of the effect of blade loading on the structure of tip leakage flow in a forward-swept axial-flow fan operating at the maximum efficiency condition ($\Phi$=0.25) and two off-design conditions ($\Phi$=0.21 and 0.30). As the blade loading increases, the onset position of the rolling-up of tip leakage flow moves upstream and the trajectory of tip leakage vortex center is more inclined toward the circumferential direction. Because the casing boundary layer becomes thicker and the mixing between the through-flow and the leakage jet with the different flow direction is enforced, the streamwise vorticity decays more fast with the blade loading increasing. A distinct tip leakage vortex is observed downstream of the blade trailing edge at $\Phi$=0.30, but it is not observed at $\Phi$=0.21 and 0.25.

Keywords

References

  1. J. Acoust. Soc. America v.101 Active control of axial-flow fan noise Lauchle,G.C.;MacGillivray,J.R.;Swanson,D.C.
  2. J. Sound Vibration v.218 no.2 High frequency noise generation in small axial flow fans Quinlan,D.A.;Bent,D.A.
  3. ASEM J. Eng. Power v.105 Investigation of the tip clearance flow inside and at the exit of a compressor rotor pass-age-Part I: mean velocity field Pandya,A.;Lakshminarayana,B.
  4. ASME J. Eng. Power v.105 Investigation of the tip clearance flow inside and at the exit of a compressor rotor pass-age-Part II: turbulence properties Pandya,A.;Lakshminarayana,B.
  5. ASME J. Eng. Power v.106 Tip clearance flow in a compressor rotor passage at design and off-design conditions Lakshminarayana,B.;Pandya,A.
  6. Trans. KSME(B) v.23 Numerical analysis on the blade tip clearance flow in the axial rotor (II)-Variation of leakage vortex with tip clearance and attack angle Ro,S.H.;Cho,K.R.
  7. ASME J. Eng. Power v.104 Casing wall boundary-layer development through an isolated compressor rotor Hunter,I.H.;Cumpsty,N.A.
  8. Ph. D. thesis An Experimental Study on the Tip Region Flow in an Axial-Flow Fan Myung,H.J.
  9. Int. J. JSME(B) v.42 Mean velocity characteristics behind a forward-swept axial-flow fan Myung,H.J.;Baek,J.H.
  10. User's guide ver.5 FLUENT
  11. Proc. 1st National Cong. Fluids Eng. A study of the flows of an axial flow fan Myung,H.J.;Baek,J.H.;Lee,I.S.
  12. Proc. of KFMA Meeting Turbulence chracteristics of a leakage vortex in an axial-flow fan Myung,H.J.;Baek,J.H.;Rew,H.S.;Lee,I.S.
  13. Proc. of SAREK Meeting Measurement of the flow behind an axial-flow fan using three-dimensional LDV Myung,H.J.;Baek,J.H.
  14. Proc. of KFMA Meeting Structure of tip leakage flow in a forward-swept axial-flow fan Lee,G.H.;Myung,H.J.;Baek,J.H.
  15. User's guide ver.1 GAMBIT
  16. Turbulence and Combustion Structure of tip leakage flow in a forward-swept axial-flow fan, submitted to Flow Lee,G.H.;Baek,J.H.;Myung,H.J.
  17. Final report Numerical analysis of internal flow through impeller for matching turbocharger Lee,G.H.;Baek,J.H.
  18. J. Turbomachinery v.111 Structure of tip clearance flow in an isolated axial compressor rotor Inoue,M.;Kuroumaru,M.
  19. Proc. Royal Society v.A211 On sound generated aerodynamically: 1. General theory Lighthill,M.J.