http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
저온 디젤 연소에서 스월비에 따른 CO 배출 및 연비 변화
국상훈(Sanghoon Kook),Paul C. Miles(Paul C. Miles),Michael Bergin(Michael Bergin),배충식(Choongsik Bae) 한국자동차공학회 2005 한국자동차공학회 춘 추계 학술대회 논문집 Vol.2005 No.11_1
Engine-out CO emission was measured over a wide range of swirl ratios and injection timings on low-temperature diesel combustion regime in a small~bore single-cylinder diesel engine. Our previous work has shown that late-cycle mixing plays an important role even in so-called dilution-controlled low-temperature combustion systems. In this study. we employ multi-dimensional numerical simulation to characterize the flow structures and their impact on CO emissions. 65% exhaust gas recirculation is simulated with additional N₂ and CO₂, The CO emission shows optimal values at swirl ratio of 2.59 and limited ranges of injection timings. The numerical simulations show that the formed CO is trapped inside bowl at high swirl of 7.12. while CO is lifted out due to an enhanced reverse squish flow with a swirl ratio of 2.59. For a lower swirl ratio of 1.44, the existence of a single, large bulk flow structure limits the mixing process. The measured fuel conversion efficiency shows maximum value at low swirl ratio. The source of the maxima is clarified by the analysis of the work conversion efficiency, combustion efficiency, and heat transfer loss. Results show heat loss plays important role in determining the fuel conversion efficiency.