• Title/Summary/Keyword: 순압력계수

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Three-dimensional Flow and Aerodynamic Loss Downstream of First-Stage Turbine Vane Cascade (터빈 제1단 정익 익렬 하류에서의 3차원 유동 및 압력손실)

  • Jeong, Jae Sung;Bong, Seon Woo;Lee, Sang Woo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.41 no.8
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    • pp.521-529
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    • 2017
  • Three-dimensional flow characteristics within a high-acceleration first-stage turbine vane passage has been investigated in a newly-built vane cascade for propulsion. The result shows that there is a strong favorable pressure gradient on the vane pressure surface. On its suction surface, however, there exists not only a much stronger favorable pressure gradient than that on the pressure surface upstream of the mid-chord but also a subsequent adverse pressure gradient downstream of it. By employing two different oil-film methods with upstream coating and full-coverage coating, a four-vortex model horseshoe vortex system can be identified ahead of each leading edge in the cascade, and the separation line of inlet boundary layer flow as well as the separation line of re-attached flow is provided as well. In addition, basic flow data such as secondary flow, aerodynamic loss, and flow turning angle downstream of the cascade are obtained.

Peak Net Pressure Coefficients for Cladding Design of Retractable Dome Roofs according to Rise-Span Ratio (라이즈-스팬 비에 따른 개폐식 돔 지붕의 외장재 설계용 피크순압력계수)

  • Cheon, Dong-Jin;Kim, Yong-Chul
    • Journal of Korean Association for Spatial Structures
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    • v.24 no.2
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    • pp.101-109
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    • 2024
  • In this study, the characteristics of wind pressure distribution on circular retractable dome roofs with a low rise-to-span ratio were analyzed under various approaching flow conditions by obtaining and analyzing wind pressures under three different turbulent boundary layers. Compared to the results of previous studies with a rise-to-span ratio of 0.1, it was confirmed that a lower rise-to-span ratio increases the reattachment length of the separated approaching flow, thereby increasing the influence of negative pressure. Additionally, it was found that wind pressures varied significantly according to the characteristics of the turbulence intensity. Based on these experimental results, a model for peak net pressure coefficients for cladding design was proposed, considering variations in turbulence intensity and height.