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Design Sensitivity Estimation of Injector Nozzle Hole Considering Cavitation

캐비테이션에 관한 인젝터 노즐 홀의 설계민감도 평가

  • 염정국 (동아대학교 기계공학과) ;
  • 하형수 (동아대학교 기계공학과)
  • Received : 2013.04.08
  • Accepted : 2013.08.11
  • Published : 2013.11.01

Abstract

This study performs a computational fluid dynamics (CFD) analysis of the inner flow of a multihole injector nozzle by using ANSYS CFX 13.0. Based on the obtained results, a design of experiment (DOE) was performed and applied to investigate the effects of injector nozzle design parameters on cavitation. To analyze the design sensitivity and signal-to-noise ratio (S/N ratio), the hole diameter, hole length, hole angle, and K-factor of the nozzle hole were selected as design parameters, and the effect of these parameters was investigated at 16 experimental points. Consequently, it was found that the effect of the K-factor on the cavitation and inner flow of the injector nozzle is the greatest. Thus, the selection of a suitable K-factor is important in nozzle design considering cavitation flow.

본 연구에서는 다공홀 인젝터 내부 유동에 대한 CFD 시뮬레이션 해석(ANSYS 13.0 CFX)을 직접 수행하였다. 이러한 결과를 바탕으로 인젝터 노즐 설계변수가 캐비테이션에 미치는 영향을 파악하기 위해 실험계획법이 적용되었다. 각 설계변수의 설계민감도 및 신호 대 잡음비 분석을 위해 캐비테이션 유동에 영향을 미친다고 판단되는 설계변수는 노즐 홀 직경, 노즐 홀 길이, 노즐 홀 각도 및 노즐 홀의 K-factor로 지정하였다. 또한 16 개 실험점으로 각 변수의 영향을 분석하였다. 본 연구에서 노즐 내부유동을 파악하기 위하여 수치해석 프로그램과 신호 대 잡음비 분석이 본 논문에 적용되었고 그 결과, K-factor의 변화가 노즐 홀 길이와 노즐 홀 각도의 변화보다 인젝터 내부 캐비테이션 생성에 미치는 영향이 더 크다는 것을 알 수 있었다.

Keywords

References

  1. Powell, C. F., Kastengren, A. L., Liu, Z and Fezzaa, K., 2011, "The Effects of Diesel Injector Needle Motion on Spray Structure," Trans. of the ASME, Vol. 133, Issue 1, pp. 012802-1-012802-9.
  2. Wang, Y., Lee, W. G., Reitz, R. and Diwakar, R., 2011, "Numerical Simulation of Diesel Sprays Using an Eulerian-Lagrangian Spray and Atomization (ELSA) Model Coupled with Nozzle Flow," SAE Technical Paper 2011-01-0386.
  3. Park, W. A., Lee, H. W. and Min, K. D., 2012, "Evaluation of Droplet Breakup Models and Application to the Diesel Engine Combustion Analysis," Trans. of KSAE, Vol. 21, No. 1, pp. 86-91. https://doi.org/10.7467/KSAE.2013.21.1.086
  4. Stiesch, G., 2003, Modeling Engine Spray and Combustion Process, Springer, New York, pp. 119-192.
  5. Baumgarten, C., Stegemann, J. and Merker, G. P., 2002, "A New Model for Cavitation Induced Primary Break-up of Diesel Sprays," ILASS-Europe 2002, Zaragoza 9-11.
  6. Kim, J. H. and Song, K. K., 1999, "Visualization of the Flow in a Diesel Injection Nozzle in Case of the Steady Flow Condition," Trans. of KSAE, Vol. 7, No. 6, pp. 49-56.
  7. Mitroglou, N., Gavaises, M., Nouri, J. M. and Arcoumanis, C., 2011, "Cavitation Inside Enlarged and Real-size Fully Transparent Injector Nozzles and Its Effect on Near Nozzle Spray Formation," DIPSI Workshop 2011 on Droplet Impact Phenomena & Spray Investigation.
  8. Lee, S. B., 2000, Well Defined Taguchi Method, Sangjosa, Seoul, pp. 15-45.
  9. Kim, Y. R. and Song, H. H., 2012, "Effect of Injector Design Parameter on Nozzle Coking in Diesel Engines," Journal of ISASS-Korea, Vol. 17, No. 3, pp. 140-145. https://doi.org/10.15435/JILASSKR.2012.17.3.140
  10. 2009, ANSYS CFX-Solver Theory Guide Release 12.0, ANSYS. Inc., Canonsburg, pp. 54-56.
  11. Giannadakis, E., Gavaises, M. and Arcoumanis, C., 2008, "Modelling of Cavitation in Diesel Injector Nozzles," J. Fluid mech., Vol. 616, pp. 153-193. https://doi.org/10.1017/S0022112008003777