• 제목/요약/키워드: 대형이차와류

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핵연료집합체에서의 대형이차와류 혼합날개의 열전달 특성에 관한 연구 (A Study of Beat Transfer Characteristics of Large Scale Vortex Flow Mixing Vane of Nuclear Fuel Rod Bundle)

  • 안정수;최영돈
    • 대한기계학회논문집B
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    • 제30권1호
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    • pp.24-31
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    • 2006
  • Mixing vanes have been installed in the space grid of nuclear fuel rod bundle to improve turbulent heat transfer. Split mixing vanes induce the vortex flow in the cooling water to swirl in sub-channel of fuel assembly. But, The swirling flow decays rapidly so that the heat transfer enhancing effect limited to short length after the mixing vane. In thi present study, the large scale vortex flow(LSVF) is generated by rearranging the mixing vanes to the coordinated directions. This LSVF mixing vanes generate the most strong secondary flow vortices which maintain about 35 $D_H$ after the spacer grid. The streamwise vorticity generated by LSVF sustain two times more than that split mixing vane. Heat transfer in the rod bundle occurs greatly at the same direction to cross flow, and maximum temperature at the surface of bundle drops about 1.5K

핵연료집합체에서의 대형이차와류 혼합날개의 난류생성 특성에 관한 연구 (A Study of Turbulence Generation Characteristics of Large Scale Vortex Flow Mixing Vane of Nuclear Fuel Rod Bundle)

  • 안정수;최영돈
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.1819-1824
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    • 2004
  • The common method to improve heat transfer in Nuclear fuel rod bundle is install a mixing vane in space grid. The previous split mixing vane is guides cooling water to swirl flow in sub-channel of fuel assembly. But, this swirl flow decade rapidly after mixing vane and the effect of enhancing the heat transfer vanish behind this short region. The large scale secondary vortex flow was generated by rearranging the inclined angle direction of mixing vanes to the coordinated directions. This LSVF mixing vanes generate the most strong secondary flow vortices which maintain about 35 $D_H$ after the spacer grid and the streamwise vorticity in subchannel with LSVF mixing vane sustain two times more than that in subchannel with split mixing vane. The turbulent kinetic energy and the Reynolds stresses generated by the mixing vanes have nearly same scales but maintain twice more than previous type.

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핵연료 집합체에서의 대형 이차 와류 혼합날개의 난류생성 특성에 관한 연구 (A Study of Turbulence Generation Characteristics of Large Scale Vortex Flow Mixing Vane of Nuclear Fuel Rod Bundle)

  • 안정수;최영돈
    • 설비공학논문집
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    • 제18권10호
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    • pp.811-818
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    • 2006
  • Mixing vanes have been installed in the space grid of nuclear fuel rod bundle to improve turbulent heat transfer. Split mixing vanes induce the vortex flow in the cooling water to swirl in sub-channel of fuel assembly. But, The swirling flow decays rapidly so that the heat transfer enhancing effect limited to short length after the mixing vane. In the present study, the large scale vortex flow (LSVF) is generated by rearranging the mixing vanes to the coordinated directions. This LSVF mixing vanes generate the most strong secondary flow vortices which maintain about $35D_h$ after the spacer grid. The streamwise vorticity generated by LSVF sustain two times more than that split mixing vane.