Transactions of the Korean Society of Mechanical Engineers A (대한기계학회논문집A)

The Korean Society of Mechanical Engineers (대한기계학회)
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Numerical Study of Breakup Process of Diesel Spray

디젤분무의 분열과정에 대한 수치해석 연구

  • 염정국 (동아대학교 기계공학과) ;
  • 정우성 (동아대학교 기계공학과)
  • Received : 2013.04.08
  • Accepted : 2013.10.04
  • Published : 2013.12.01
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Abstract

High-pressure flows are ubiquitous in many industrial fields. A representative application is fuel injection using a common-rail control system in diesel engines, where the injection pressure in the injector exceeds 1000 bar. In high-speed injection, the fluid injected through the nozzle undergoes breakup owing to the interaction with the ambient gas. The breakup process influences mixture formation, which in turn influences combustion in diesel engines. Therefore, it is very important to analyze the breakup process of fuel spray. The Reitz and Diwakar model and cascade atomization and breakup (CAB) model were used in this study as sub-models for the numerical analysis of the breakup process of fuel spray. This study aims to precisely analyze the breakup process of spray and to investigate the breakup frequency of the injected fuel. Consequently, it proposes a suitable sub-model for analyzing the breakup process of a diesel spray by using CFX, a commercial CFD program.

유체의 고압유동은 여러 산업현장에 활용되고, 특히 그 중 내연기관의 연료분사 인젝터가 대표적이며 디젤엔진의 커먼레일 시스템의 경우 1000bar 이상의 압력이 사용된다. 이와 같이 고속으로 분출되는 유체유동의 경우, 노즐을 통해 분사되는 고속의 유체는 주위기체와의 상호작용으로 분열과정을 거치게 된다. 이 분열과정은 연소실 혼합기형성기과정에 영향을 주게 되며, 그 결과 엔진의 연소상태에 까지 영향을 미치게 된다. 따라서 연료분무의 분열과정에 대한 해석은 중요하며, 본 연구에서는 연료분무의 분열을 위한 수치해석 서브모델로 Reitz&Diwakar 및 CAB(Cascade atomization and breakup)모델을 사용하였다. 본 연구의 목적은 분사된 분무의 분열과정의 정확한 해석이며, 분사연료의 분열발생 형태의 빈도 등을 조사하였다. 결과로서 본 연구는 상용 CFD 프로그램(CFX)을 이용하여 디젤분무의 분열과정해석을 위한 적합한 분열모델을 제안한다.

Keywords

References

  1. Lee, S. D. and Jung, S. H., 2013, "Comparison of Combustion Characteristics Between Esterified and Non-esterified Bio-diesel Oil on CRDI Diesel Engine with Turbocharger," Journal of the Korean Society of Marine Engineering, Vol. 37, No. 1, pp. 53-58. https://doi.org/10.5916/jkosme.2013.37.1.53
  2. Lee, S. H., Kim, H. S., Park, J. H. and Cho, P. B., 2012, "On-Road Investigation of PM Emissions According to Vehicle Fuels(Diesel, DME and Bio-Diesel)," Transactions of KSAE, Vol. 20, No. 3, pp. 88-97. https://doi.org/10.7467/KSAE.2012.20.3.088
  3. Jeong, K. S., Lee, D. G., Roh, H. G. and Lee, C. S., 2011, "Effect of Pilot Injection on Combustion and Exhaust Emissions Characteristics in a Biodiesel Fueled Diesel Engine," Journal of the Korean Society of Combustion, Vol. 16, No. 4, pp. 1-7.
  4. Park, W. A., Lee, H. W. and Min, K. D., 2013, "Evaluation of Droplet Breakup Models and Application to the Diesel Engine Combustion Analysis," Transactions of KSAE, Vol. 21, No. 1, pp. 86-91. https://doi.org/10.7467/KSAE.2013.21.1.086
  5. Desantes, J. M., Payri, R., Salvador, F. J. and Gil, A., 2006, "Development and Validation of a Theoretical Model for Diesel Spray Penetration," Fuel, Vol. 85, Issues 7-8, pp. 910-917. https://doi.org/10.1016/j.fuel.2005.10.023
  6. Park, S. H., Kim, H. J., Kim, S. H. and Lee, C. S., 2010, "Spray-Atomization Characteristics of Biodiesel Fuel with Multiple Injection," Transactions of KSAE, Vol. 18, No. 4, pp. 40-47.
  7. Yeom, J. K., 2011, "Basic Experimental Study on the Application of Biofuel to a Diesel Engine," Trans. Korean Soc. Mech. Eng. B, Vol. 35, No. 11, pp. 1163-1168. https://doi.org/10.3795/KSME-B.2011.35.11.1163
  8. Lee, S. R., 1994, "Internal Combustion Engine, BOSUNGKAK, Seoul, pp. 231-233.
  9. Park, S. H., Youn, I. M., Lim, Y. S. and Lee, C. S., 2013, "Influence of the Mixture of Gasoline and Diesel Fuels on Droplet Atomization, Combustion and Exhaust Emission Characteristics in a Compression Ignition Engine," ELSEVIER, Vol. 106, pp. 392-401. https://doi.org/10.1016/j.fuproc.2012.09.004
  10. Liu, A. B. and Reitz, R. D., 1993, "Mechanisms of Air-assisted Liquid Atomization," Atomization and Sprays, Vol. 3, pp. 1-27. https://doi.org/10.1615/AtomizSpr.v3.i1.10
  11. Hossainpour, S. and Binesh, A. R., 2009, "Investigation of Fuel Spray Atomization in DI Heavy-Duty Diesel Engine and Comparison of Various Spray Breakup Models," FUEL, Vol. 88, pp. 799-805. https://doi.org/10.1016/j.fuel.2008.10.036