• Title/Summary/Keyword: Disel Injection

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Visualization of the Flow in a Diesel Injection Nozzle In case of the Steady Flow Condition (정상류 조건에서의 디젤 연료 분사 노즐내의 유동가시화)

  • 김장헌;송규근
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.6
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    • pp.49-56
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    • 1999
  • The effects of the internal flow in a D.I. Diesel injection nozzle on the atomization of a spray were analyzed experimentally. Flow visualization studies were made using a transparent acrylic model nozzle as a diesel nozzle . Water instead of disel fuel was used as the injection liquid. The geometry of the model nozzle was scaled up 10 times of the actual nozzle and the injection pressure for the model nozzle was adjusted so as to achieve a Reynolds number at the discharge hole that was the same as the actual nozzle. Experimental results show that when the needle lift was small, the high turbulence in the sac chamber generated by the high velocity seat flow made the spread angle of the spray plume large. Cavitation, which arose from the sac chamber, makes the spread angle of the spray plume large but the discharge coefficient small.

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Expansion of Operating Range and Reduction of BSFC in Low Temperature Diesel Combustion with Boosting (과급을 이용한 저온 디젤 연소의 운전영역 확장 및 연료소비율 저감)

  • Shim, Eui-Joon;Han, Sang-Wook;Jang, Jin-Young;Park, Jung-Seo;Bae, Choong-Sik
    • Proceedings of the KSME Conference
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    • 2008.11b
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    • pp.3013-3018
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    • 2008
  • Supercharging system was adopted to investigate the influence of boost pressure on operating range, brake specific fuel consumption (BSFC) and exhaust emissions by using a supercharger at low temperature diesel combustion (LTC) condition in a 5-cylinder 2.7 L direct injection diesel engine. The experimental parameters such as injection quantity, injection timing, injection pressure and exhaust gas recirculation (EGR) rate were varied to find maximum operating range. The result showed that operating range with boost was expanded up to 41.9% compared to naturally aspirated LTC condition due to increased mixing intensity. The boosted LTC engine showed low BSFC value and dramatically reduced soot emission under all operating range compared with high speed direct injection (HSDI) mode. Finally, this paper presents the boosted LTC map of emission and the strategy of improved engine operating range.

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Numerical analysis on the characteristics of disel spray for variation of injection spray angle and swirl ratio. (분사각 및 스월 변화에 따른 디젤분무의 특성에 관한 수치 해석)

  • Jung H.;Cha K. S.;Park C. G.
    • Journal of computational fluids engineering
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    • v.5 no.3
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    • pp.1-7
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    • 2000
  • In high-pressure diesel engine, the injected fuel spray impinges on the piston cavity surface due to the short distance between the injection nozzle and the cavity wall. The behavior of the impinging spray has the great influence on the dispersion of fuel, the evaporation, and the mixture formation process. In this study, the numerical simulation using the GTT code was performed to study the gas flows, the spray behaviors, and the fuel vapor distributions in the combustion of a D.I engine for variation of spray angle and swirl ratio.

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Lab-Scale Air/Bio-Sparging Study to Remediate Diesel-Contaminated Soil and Groundwater : The Effect of Air Injection Rate and Pattern (디젤오염 토양 및 지하수 복원을 위한 공기주입정화법 실험실 연구 : 공기주입량과 공기주입방식의 영향)

  • Chang, Soon-Woong;Lee, Si-Jin;Cho, Su-Hyung;Yoon, Jun-Ki
    • Journal of Soil and Groundwater Environment
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    • v.11 no.4
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    • pp.10-17
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    • 2006
  • Laboratory-scale two-dimensional aquifer physical model studies were conducted to assess the effect of air injection rate and air injection pattern on the removal of disel contaminated soil and groundwater by air/bio-sparging. The experimental results were represented that the optimal conditions in this experiment were as air injection rate of 1,000 ml/min and pulsed air injection pattern(15 min on/off). The results of the TPH reduction, DO consumption and $CO_2$ production indicate the effective biodegradation evidence of diesel. Based on our results, The minimal $O_2$ supply and pulsed air injection pattern could effectively enhance the diesel removal and the pulsing air injection had effect on oxygenation in this system. Thus, the cost of operating air/bio-sparging system will be reduced if optimal air injection rate and pulsed air injection pattern are applied to remediate contaminants.

Analysis of Performance Characteristics on Diesel Engine with Aftertreatment and EGR System (후처리 시스템을 장착한 디젤엔진의 EGR 밸브 작동에 따른 성능 분석)

  • Park, Cheol-Woong;Choi, Young;Lim, Gi-Hun
    • Transactions of the Korean Society of Automotive Engineers
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    • v.18 no.5
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    • pp.124-129
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    • 2010
  • The direct injection (DI) diesel engine has become a prime candidate for future transportation needs because of its high thermal efficiency. However, nitrogen oxides (NOx) increase in the local high temperature regions and particulate matter (PM) increases in the diffusion flame region within diesel combustion. Therefore, the demand for developing hybrid system consist of exhaust gas recirculation (EGR) and aftertreatment system as well as diesel particulate filter (DPF) or lean NOx trap (LNT) should be applied. The variation of EGR rate due to the malfunction of EGR valve can affect not only the combustion stability of engine but also the performance of aftertreatment system. In this research, 2.0 liter 4-cylinder turbocharged diesel engine was used to investigate the combustion and emission characteristics for various operating conditions with EGR. While the fuel consumption was increased with increase of EGR rate, NOx emission was improved by maximum 90% at low speed, low load operating condition. To achieve combustion stability and reliability of aftertrearment system with minimum penalty in fuel consumption and emissions, the fault diagnosis of EGR malfunction must be employed.