• 제목/요약/키워드: KH-RT 분열모델

검색결과 3건 처리시간 0.024초

분열모델 상수가 분무 및 연소특성에 미치는 영향 (Effects of Spray Breakup Model Variables on Spray and Combustion Characteristics)

  • 이승필;박준규;박성욱
    • 한국분무공학회지
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    • 제22권1호
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    • pp.29-35
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    • 2017
  • This paper describes the effects of spray breakup model constants on spray and combustion characteristics in single cylinder compression engine. KIVA-3V code coupled with a CHEMKIN chemistry solver was used for numerical analysis. In this study, spray simulations and combustion simulations are studied simultaneously. Spray simulation was conducted in constant volume to reduce the effects of air-flow as swirl or tumble. The model validation was conducted and there are little difference between experiments and simulation, this differences were reasonable. In spray simulation, the effects of model constants on spray tip penetration, spray patter and SMD were studied. Furthermore, the analysis of effects of breakup variables on combustion and emissions characteristics was conducted. The results show the KH-RT breakup model constants affects spray and combustion characteristics strongly. Increasing KH model variable (B1) and RT model constants ($C_{\tau}$, $C_{RT}$) induced slower breakup time.

횡단류에 분사되는 액체 제트의 분무 및 연소 특성 (Spray and Combustion Characteristics of Liquid Jet in Cross Flow)

  • 이관형;김두만;구자예;황진석
    • 한국항공우주학회지
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    • 제34권12호
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    • pp.48-58
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    • 2006
  • 횡단류에 분사되는 액체 제트의 분무 및 연소 특성에 대한 수치적 연구를 수행하였다. 수치 계산을 위해 3차원의 분무 및 화학반응 유동 해석에 유용한 KIVA 코드를 횡단류에서의 분무 해석에 적합하도록 수정하여 사용하였다. 액주의 분열과 리거먼트 및 액적의 분열 현상을 해석하기 위하여 wave 모델과 KH-RT hybrid 모델이 사용되었다. 침투길이는 유입공기의 속도가 감소하거나 분사속도가 증가함에 따라 증가하였다. 유입공기의 속도가 증가할수록 계산결과의 오차가 크게 발생함을 알 수 있었다. 연소 특성에 대한 수치 해석으로 연소실 내부의 화염전파 형상과 국부지역에서의 온도및 공해 배출량에 대한 결과를 얻었다.

분사각 변화에 따른 횡단류에 분사되는 액체제트의 분무특성에 대한 수치적 연구 (Numerical Study for Spray Characteristics of Liquid Jet in Cross Flow with Variation of Injection Angle)

  • 이관형;고정빈;구자예
    • 대한기계학회논문집B
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    • 제30권2호
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    • pp.161-169
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    • 2006
  • The spray characteristics of liquid jet in cross flow with variation of injection angle are numerically studied. Numerical analysis was carried out using KIVA code, which was modified to be suitable for simulating liquid jet ejected into cross flow. Wave model and Kelvin-Helmholtz(KH)/Rayleigh-Taylor(RT) hybrid model were used for the purpose of analyzing liquid column, ligament, and the breakup of droplet. Numerical results were compared with experimental data in order to verify the reliability of the physical model. Liquid jet penetration length, volume flux, droplet velocity profile and SMD were obtained. Penetration length increases as flow velocity decreases and injection velocity increases. From the bottom wall, the SMD increases as vertical distance increases. Also the SMD decreases as injection angle increases.