• Title/Summary/Keyword: Preferred direction of gas

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A Study on the Effects on Low Cycle Fatigue Life of a High Pressure Turbine Nozzle due to the Perturbation of Crystal Orientation of Grain of DS Materials (일방향 응고 재료의 결정립 성장 방향 섭동이 고압터빈 노즐 저주기 피로 수명에 미치는 영향에 대한 연구)

  • Huh, Jae Sung;Kang, Young Seok;Rhee, Dong Ho
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.40 no.7
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    • pp.653-658
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    • 2016
  • High pressure components of a gas turbine engine are generally made of nickel-base superalloys, using precision casting process due to complicated geometries with intricate channels and cooling holes. Turbine components manufactured from directionally solidified and single crystal materials have columnar grains; however, it is found that the crystals do not grow in its preferred direction, although the orientation can be controlled. This anisotropy can lead to the variations of elastic and Hill's parameters in constitutive equations, and they alter stress distributions and the low cycle fatigue life. We aims to evaluate the effects of perturbed crystal orientations on the structural integrity of a directionally solidified nozzle using low cycle fatigue life. We also attempt to show the necessity for the control of allowed manufacturing errors and stochastic analysis. Our approaches included conjugate heat transfer and structural analysis, along with low cycle fatigue life assessment.