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Dimethyl Ether(DME) 연료의 분무 거동 및 미립화 특성
서현규,박지홍,이창식,Suh, Hyun-Kyu,Park, Ji-Hong,Lee, Chang-Sik 한국자동차공학회 2007 한국 자동차공학회논문집 Vol.15 No.5
Dimethyl Ether(DME) is an alternative fuel for diesel engine, it is renewable and offers potential reductions in emissions. This work was conducted to figure out the macroscopic behavior and the atomization characteristics of DME using a common-rail injection system. The macroscopic behavior was visualized with the spray visualization system composed of a Nd;YAG laser and an ICCD camera. The atomization characteristics were investigated in terms of axial mean velocity, Sauter mean diameter(SMD) and droplet distributions obtained from a phase Doppler particle analyzer(PDPA) system. In this study, it was revealed that the macroscopic behavior and the atomization characteristics of DME are similar compared with commercial diesel fuel. However, DME fuel has a shorter spray tip penetration and a small SMD due to the effect of evaporation characteristics.
노즐 형상에 따른 디젤 연료 분무 도달거리 예측에 관한 수치해석적 검증
서현규 ( Hyun Kyu Suh ),민세훈 ( Se Hun Min ) 한국액체미립화학회 2016 한국액체미립화학회 학술강연회 논문집 Vol.2016 No.-
The objective of this study was to verify the experimental and numerical results of spray tip penetration injected from different types of the nozzle-hole geometries. Spray visualization was taken by high speed camera under the different test conditions. For the simulations of spray evolution, turbulence, evaporation and breakup model were applied K-zeta-f, Dukowicz and Wave model, respectively. The prediction accuracy of spray tip penetration was increased by the varying of the spray cone angle. At the same time, the results of this work were compared in terms of spray tip penetration, and SMD characteristics. The numerical results of spray evolution process and spray tip penetration showed good agreement with experimental one.
CO<sub>2</sub>를 포함한 Simulated-EGR 압축착화엔진에서 당량비 변화에 따른 성능 예측
서현규 ( Hyun Kyu Suh ) 한국액체미립화학회 2020 한국액체미립화학회지 Vol.25 No.1
The objective of this work is to numerically reveal the effect of equivalence ratio change on the simultaneous reduction of NO<sub>X</sub> and soot emissions from the simulated-EGR compression ignition engine containing CO<sub>2</sub>. An experiment was conducted by using a single-cylinder common-rail injection system engine, an intake control system, and exhaust emissions analyzers. The numerical analysis results were validated under the same experimental conditions. To investigate the effect of equivalence ratio by simulated-EGR containing CO<sub>2</sub>, the O<sub>2</sub>, N<sub>2</sub>, and CO<sub>2</sub> mole fraction were changed in the initial air conditions to the cylinder. The results were analyzed in terms of peak cylinder pressure, indicated mean effective pressure, indicated specific nitrogen oxide, and indicated specific soot. It was revealed that ignition delay characteristics and heat release rate (ROHR) characteristics were not significantly different according to the equivalence ratio. However, as the equivalence ratio increased from 0.68 to 0.83, the maximum combustion pressure and IMEP decreased by about 6.5% and 9.4%, respectively. In the case of ISFC, as is well known, the trend is opposite of IMEP. In the case of ISNO, as the equivalence ratio increased, less NO was generated, and as the equivalence ratio increased by 0.05, the ISSoot value of about 10% increased.
함산소 바이오디젤 연료의 혼합기 형성 및 미립화 증진에 관한 연구
서현규(Hyun Kyu Suh),박성욱(Sung Wook Park),이창식(Chang Sik Lee) 한국자동차공학회 2012 한국자동차공학회 학술대회 및 전시회 Vol.2012 No.11
In this work, the improvement of mixture formation and atomization characteristics of biodiesel fuel were analyzed under various test conditions for the optimization of compression-ignition engine fueled with biodiesel. To achieve these, effect of nozzle caviting flow, group-hole nozzle geometry and injection strategies on the injection rate, spray evolution and atomization characteristics of biodiesel were studied by using spray characteristics measuring system. At the same time, the fuel heating system was installed to obtain the effect of fuel temperature on the biodiesel fuel atomization. It was revealed that cavitation in the nozzle orifice promotes the atomization performance of biodiesel. The group-hole nozzle geometry and split injection strategies can not improve it, however, the different orifice angles which is diverged and converged angle in a group-hole nozzle enhance the biodiesel atomization. It was also observed that the increase of fuel temperature induces the quick evaporation of biodiesel fuel droplet.
서현규 ( Hyun Kyu Suh ),임영찬 ( Young Chan Lim ) 한국액체미립화학회 2014 한국액체미립화학회 학술강연회 논문집 Vol.2014 No.-
The motivation for this investigation was to enhance the understanding of the influence of ambient conditions on the sooting behaviors of decane droplet. To achieve this, preliminary experiments on the effects of oxygen (O2) concentration, ambient pressure (Pamb), and initial droplet diameter (d0) on the decane droplet combustion will be described. At the same time, experimental measurements of the sooting behavior such as soot volume fraction (fv), burning rate (K), and soot standoff ratio (SSR) for isolated decane droplet combustion experiments are described under complete observation condition of the droplet burning. These new observations provide important insights into the burning and sooting behavior of droplet flames and can be used as benchmarks to calibrate evolving models for droplet combustion.