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가스터빈엔진 디스크의 도브테일 형상 최적화와 신뢰도 해석

Shape Optimization and Reliability Analysis of the Dovetail of the Disk of a Gas Turbine Engine

  • 허재성 (한국항공우주연구원 항공엔진실)
  • Huh, Jae-Sung (Aero-propulsion Division, Korea Aerospace Research Institute)
  • 투고 : 2013.11.07
  • 심사 : 2014.02.02
  • 발행 : 2014.04.01

초록

가스터빈엔진의 가장 핵심 부품인 디스크와 블레이드는 고온, 고압축비, 고속 회전이라는 가혹한 환경에서 지속적으로 운용된다. 이러한 가혹한 환경과 디스크와 블레이드가 가지는 큰 회전 에너지로 인해 디스크 및 블레이드에 의해 유발되는 파손은 항공기 손상 혹은 탑승자의 피해로 이어지는 재해적 고장 혹은 한계 고장으로 이어진다. 그러므로 디스크와 블레이드의 구조적 건전성의 마진을 충분히 확보하기 위해서 본 연구에서는 디스크의 취약 부위인 도브테일의 형상을 최적화하고, 그 해의 강건성을 확인하기 위해 치수 공차와 피로 수명의 산포와 같은 불확실성에 대하여 신뢰도 해석을 수행하고자 한다. 이 결과를 통해 결정론적 방법인 최적설계의 필요성과 함께 한계를 확인하고, 향후 신뢰도 기반 최적설계의 필요성을 인지하고자 한다. 이를 위해 비선형 열-구조 연성해석과 접촉 해석을 포함한 유한요소해석을 수행하였다.

The most critical rotating parts of a gas turbine engine are turbine blades and disc, given that they must operate under severe conditions such as high turbine inlet temperature, high speeds, and high compression ratios. Owing to theses operating conditions and high rotational speed energy, some failures caused by turbine disks and blades are categorized into catastrophic and critical, respectively. To maximize the margin of structural integrity, we aim to optimize the vulnerable area of disc-blade interface region. Then, to check the robustness of the obtained optimized solution, we evaluated structural reliability under uncertainties such as dimensional tolerance and fatigue life variant. The results highlighted the necessity for and limitations of optimization which is one of deterministic methods, and pointed out the requirement for introducing reliability-based design optimization which is one of stochastic methods. Thermal-structural coupled-filed analysis and contact analysis are performed for them.

키워드

참고문헌

  1. Cheu, T. C., 1990, "Procedures for Shape Optimization of Gas Turbine Disks," Computers & Structures, Vol. 34, No. 1, pp.1-4. https://doi.org/10.1016/0045-7949(90)90295-D
  2. Liu, J. S., Parks, G. T. and Clarkson, P. J., 2002, "Optimization of Turbine Disk Profiles by Metamorphic Development," Transactions of the ASME, Vo. 124, pp.192-200. https://doi.org/10.1115/1.1467079
  3. Rao, A. R., Scanlan, J. P. and Keane, A. J., 2007, "Applying Multiobjective Cost and Weight Optimization to the Initial Design of Turbine Disks" Journal of Mechanical Design, Vol.129, pp.1303-1310. https://doi.org/10.1115/1.2779899
  4. Rao, J. S., Kishore, C. B. and Mahadevappa, V., 2008, "Weight Optimization of Turbine Blades," 12th Intl. Symp. on Transport Phenomena and dynamics of Rotating
  5. Brujic, D., Ristic, M., Mattone, M., Maggiore, P. and De Poli, G. P., 2010, "CAD Based Shape Optimization for Gas Turbine Component Design," Structural Multidisciplinary optimization, Vol. 41, pp.647-659. https://doi.org/10.1007/s00158-009-0442-9
  6. Tryon, R. G., Cruse, T. A. and Mahadevan, S., 1996, "Development of a Reliability-Based Fatigue Life Model for Gas Turbine Engine Structures," Engineering Fracture Mechanics, Vol.53, No. 5, pp.807-828. https://doi.org/10.1016/0013-7944(95)00138-7
  7. Cruse, T. A., Mahadevan, S. and Tryon, R. G., 1997, Fatigue Reliability of Gas Turbine Engine Structures, NASA CR-97-206215.
  8. Liu, C. L., Lu, Z. Z. and Xu, Y. L., 2004, "Reliability Analysis for an Aero Engine Turbine Disk Under Low Cycle Fatigue Condition" ACTA Metallurgica Sinica, Vol. 17, No. 4, pp.514-520.
  9. Liu, C. L., Lu, Z. Z., Xu Y. L, and Yue, Z. F., 2005 "Reliability Analysis for Low Cycle Fatigue Life of the Aeronautical Engine Turbine Disc Structure Under Random Environment" Materials Science and Engineering A, Vol. 395, pp.218-225. https://doi.org/10.1016/j.msea.2004.12.014
  10. Tang, J. X. and Lu, S., 2005, "Reliability Analysis Method for the Strain Fatigue Life of a Disk," Journal of Propulsion Technology, Vol. 26, No. 4, pp.344-347.
  11. Tang, J. X. and Lu, S., 2006, "Numerical Simulation of LCF Probability Life of a Turbine Disk," Journal of Aerospace Power, Vol. 21, No. 4, pp.706-710.
  12. Hu, D. Y., Pei, Y., Wang, R. Q. and Li, Q. H., 2008, "Probabilistic Design of Low Cycle Fatigue for Turbine Disk," Journal of propulsion technology, Vol. 29, No. 4, pp.481-487.
  13. Gao, Y., Bai, G. and Zhang, Y., 2009, "Reliability Analysis of Multiaxial Low Cycle Fatigue Life for Turbine Disk," Acta Aeronautica et Astronautica Sinica, Vol. 30, No. 9, pp.1678-1682.
  14. Huh, J. S., 2013, "A Parametric Study on Gas Trubine Engine Disc by Utilizing Axisymmetry and Sector Analysis Model," Trans. Korean Soc. Mech. Eng. A, Vol. 37, No. 6, pp.769-774. https://doi.org/10.3795/KSME-A.2013.37.6.769
  15. Cullen, T. M. and Freeman, J. W., 1965, The Mechanical Properties of Inconel 718 Sheet Alloy at $800^{\circ}$, $1000^{\circ}$, and $1200^{\circ}F$, NASA CR-268.
  16. Military Standard, 2003, "Metallic Materials and Elements for Aerospace Vehicle Structure," MILHDBK-5J (USAF).
  17. Military Standard, 2002, "Engine Structural Integrity Program (ENSIP)," MIL-HDBK-1783B.
  18. Huh, J. S. and Kwak, B. M., 2007, "Numerical Verification of the First Four Statistical Moments Estimated by a Function Approximation Moment Method," Trans. Korean Soc. Mech. Eng. A, Vol. 31, No. 4, pp.490-495. https://doi.org/10.3795/KSME-A.2007.31.4.490
  19. Melchers, R. E., 1999, Structural Reliability Analysis and Prediction, John Wiley & Sons.