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Effects of a Simplified Mixture Nozzle Geometry on the Acoustic Field in an Aero Gas Turbine Combustor

항공용 가스터빈 연소기에서의 혼합기 노즐 형상의 단순화가 음향장 해석 결과에 미치는 영향

  • 표영민 (강릉원주대학교 기계자동차공학부) ;
  • 홍수민 (강릉원주대학교 기계자동차공학부) ;
  • 김대식 (강릉원주대학교 기계자동차공학부)
  • Received : 2019.05.13
  • Accepted : 2019.06.08
  • Published : 2019.06.30

Abstract

A 3D FEM (Finite Element Method) based Helmholtz solver has been commonly used to characterize fundamental acoustic behavior and investigate dynamic instability features in many combustion systems. In this approach, a geometrical simplification of the target system has been generally made in order to reduce computational time and cost because a real combustor and fuel nozzle have a very complicated flow passage. The feasibility of these simplifications is quantitatively investigated in a small aero gas turbine nozzle in term of acoustic characteristics. It is found that the simplification in a nozzle geometry during the 3D FEM analysis process has no great influence on the acoustic modeling results, while the calculation complexity can be improved for a similar modeling accuracy.

Keywords

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Fig. 2 Simplification steps of the target fuel-air mixture nozzle for 3D acoustic modeling; (a) Case 1, (b) Case 2, (c) Case 3, (d) Case 4, (e) Case 5.

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Fig. 3 Schematics of computational mesh: (a) Case 1, (b) Case 4, (c) Case 5

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Fig. 4 Schematics of lab-scale gas turbine combustor for the experiments(14) (top) and the numerical simulation (bottom).

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Fig. 5 Calculation results of 1st longitudinal and 1st circumferential modal shape for (a) Case 1 and (b) Case 5

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Fig. 6 Calculation result of 1st longitudinal modal shape at combustor length of 1.9 m.

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Fig. 1. (a) Sectional view and (b) nozzle schematics of the aero gas turbine combustor under development.

Table 1 Summary of geometrical changes for each case

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Table 2 Operating conditions and gas properties

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Table 3 Simplification effects of nozzle geometry on the predicted resonance frequency and required calculation time

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Table 4 Frequency prediction results in a lab-scale combustor rig

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References

  1. Y. Huang, H. G. Sung, S. Y. Hsieh, and V. Yang, "Large-Eddy Simulation of Combustion Dynamics of Lean-Premixed Swirl-Stabilized Combustor", Journal of Propulsion and Power, Vol. 19, No. 5, 2003, pp. 782-794. https://doi.org/10.2514/2.6194
  2. Y. Pyo, J. Kim, and D. Kim, "Time Lag Analysis Using Phase of Flame Transfer Function", Journal of ILASSKorea, Vol. 21, No. 2, 2016, pp. 104-110.
  3. K.T. Kim, G. L. Lee, H. J. Lee, B. D. Quay, and D. A. Santavicca, "Characterization of Forced Flame Response of Swirl-Stabilized Turbulent Lean-Premixed Flames in a Gas Turbine Combustor", Journal of Engineering for Gas Turbines and Power, Vol. 132, No. 4, 2010, pp. 41502-41510. https://doi.org/10.1115/1.3204532
  4. P. Wolf, R. Balakrishnan, G. Staelbach, L. Y. M. Gicquel, and T. Poinsot, "Using LES to Study Reacting Flows and Instabilities in Annular Combustion Chambers", Flow, Turbulence and Combustion, Springer Verlag, Germany, Vol. 88, 2012, pp. 191-206. https://doi.org/10.1007/s10494-011-9367-7
  5. M. G. Yoon and D. Kim, "Acoustic Transfer Function of a Combustion System with Premixing Chamber", Journal of Mechanical Science and Technology, Vol. 31. No. 12, 2017, pp. 6069-6076. https://doi.org/10.1007/s12206-017-1151-8
  6. C. F. Silva, F. Nicoud, T. Schuller, D. Durox and S. Candel, "Combining a Helmholtz Solver with the Flame Transfer Function to Assess Combustion Instability in a Premixed Swirled Combustor," Combustion and Flame, Vol. 160, No. 9, 2013, pp. 1743-1754. https://doi.org/10.1016/j.combustflame.2013.03.020
  7. S. Jang, D. Kim, S. Joo, and Y. Yoon, "Combustion Instability Modeling in a Partially-Premixed Gas Turbine Combustor Using Finite Element Method", Journal of ILASS-Korea, Vol. 23, No. 1, 2018, pp. 16-21. https://doi.org/10.15435/JILASSKR.2018.23.1.16
  8. S. K. Kim, D. Kim, and D. J. Cha, "Finite Element Analysis of Self-Excited Instabilities in a Lean Premixed Gas Turbine Combustor", International Journal of Heat and Mass Transfer, Vol. 120, 2018, pp. 350-360. https://doi.org/10.1016/j.ijheatmasstransfer.2017.12.021
  9. A. Andreini, B. Facchini, A. Giusti, and F. Turrini, "Assessment of Flame Transfer Function Formulations for the Thermoacoustic Analysis of Lean Burn Aero-Engine Combustors", Energy Procedia, Vol. 45, 2014, pp. 1422-1431. https://doi.org/10.1016/j.egypro.2014.01.149
  10. A. Andreini, B. Facchini, A. Giusti, F. Turrini and I. Vitale, "Thermo-Acoustic Analysis of an Advanced Lean Injection System in a Tubular Combustor Configulation", The proceeding of the COMSOL European Conference, 2012.
  11. M. Knadler, "Validation of a Physics-Based Low-Order Thermo-Acoustic Model of a Liquid-Fueled Gas Turbine Combustor and its Application for Predicting Combustion Driven Oscillations", Ph.D. Dissertation, Dept. of Aerospace Engineering and Engineering Mechanics, University of Cincinnati, November 2017.
  12. Comsol, Comsol Multiphysics 5.3a, www.comsol.com.
  13. D. Kim, S. Jung, and H. Park, "Design of Acoustic Liner in Small Gas Turbine Combustor Using One-Dimensional Impedance Models", Journal of Engineering for Gas Turbines and Power, Vol. 140, No. 12, 2018, pp. 121505-121515. https://doi.org/10.1115/1.4040765
  14. B. Ahn, J. Lee, S. Jung, and K. T. Kim, "Low-Frequency Combustion Instability of an Airblast Swirl Injector in a Liquid-Fuel Combustor", Combustion and Flame, Vol. 196, 2018, pp. 424-438. https://doi.org/10.1016/j.combustflame.2018.06.031