• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.8
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• pp.99-106
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• 1999

The present study deals with the effect of combustion chamber shape on in-cylinder soot oxidation characteristics of a D.I . diesel engine. The analysed combustion chambers were a toroidal and a reentrant with a projection(Complex). The two-color method was used to measure in-cylinder flame temperature and KL value which is approximately proportional to the soot amount along the optical path. In addition, heat release rate was calculated from the in-cylinder pressure data. From these investigations , the soot oxidation of the reentrant and the complex which were strengthen squish flows went worse in late combustion period under heavy-load operation compared to that of the toroidal at retarded fuel injection timing . It might be the cause of the flame holding that squish lip depress the outflow of flame from the bowl to the entire combustion space.

• Journal of ILASS-Korea
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• v.22 no.4
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• pp.203-209
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• 2017

The International maritime organization(IMO), in an effort to slow down the global warming, proposes reduction in ship's speed as a way to lower the rate emissions from ships. In addition, since ship's fuel cost have been increased, the shipping volumes, fuel-saving technology are being required urgently. Therefore, in this present study, a method of reducing the fuel cost that can improve the performance of the diesel engine was tried by introducing a predetermined amount (0.1~0.3% of the mass amount of fuel used) of hydrogen fuel additive. The experimental conditions of the test engine were 1500rpm and torque BMEP-10b ar. The engine performances (power output, fuel consumption rate, p-max, exhaust temperature) were compared before and after addition of hydrogen fuel additives. This experimental study confirmed reducing at least 2% fuel consumption and 2.19% NOx emission.

• Journal of Advanced Marine Engineering and Technology
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• v.23 no.5
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• pp.637-653
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• 1999

In this study well-known burned rate expressions of Weibe function and double Wiebe function have been adopted for the combustion analysis of large two stroke marine diesel engine. A cycle simulation program was also developed to predict the performance and pressure waves in pipes using validated burned rate function,. Levenberg-Marquardt iteration method was applied to cali-brate the shape coefficients included in double Wiebe function for the performance prediction of two-stroke marine diesel engine. As a result the performance prediction using double Wiebe func-tion is well correlated withexperimental dta with the accuracy of 5% and pressure waves in intake and transport pipe are well predicted. From the results of this study it can be confirmed that the shape coefficients of burned rate function should be modified using the numerical method suggested for the accurated prediction and double Wiebe function is more suitable than Wiebe func-tion for combustion analysis of large two stroke marine engine.

• Journal of ILASS-Korea
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• v.4 no.4
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• pp.17-23
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• 1999

Recently, many researchers have been studied a D.I. diesel engine because of the exhaust gas restriction and fuel consumption performance. It is well known that the fuel injection characteristics are the key factors on the diesel combustion and exhaust emission. In this study, the fuel injection characteristics of 5-hole injector and the combustion characteristics are investigated with the amount of fuel by means of the visualization method and visualization D.I. diesel engine system. As the results of the experiments, the spray pattern of the fuel injection and the diffusion flame of a D.I. diesel engine are clarified. In addition, combustion phenomena with operation conditions such as engine speed and engine load are made clear.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.3
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• pp.82-90
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• 1996

In a diesel engine the phenomenon of spray impaction on a chamber wall has been taken as an undesirable matter because of the deposition of fuel on the surfaces, and the subsequent slow evaporation and mixing with air resulting in unburned hydrocarbons. Therefore many researches have concentrated on avoiding fuel impingement on surfaces. On the contrary done a number of studies using spray wall impactions in a positive way, which makes the droplets smaller, changes the direction into free spaces far from the wall and also improves mixing with air. In this paper the size of the impaction site prepared for the injection spray which is raised from the bottom in the piston bowl center is analysed as both simulative and experimental manner.

• Journal of ILASS-Korea
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• v.26 no.3
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• pp.142-148
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• 2021

The objective of this study is to analyze the basic flame behavior characteristics using the single fuel droplet combustion of diesel, palm-based biodiesel, and canola-based biodiesel. The results were compared and analyzed through the post processed image, which was applied the threshold level for removing noise in the raw image. The raw image was taken by a high-speed camera during the entire combustion process. At the same time, the maximum flame length, which was measured by the application code of the MATLAB program, the ignition delay, and the combustion period were compared and analyzed.

• Journal of Power System Engineering
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• v.12 no.2
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• pp.12-17
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• 2008

Biodiesel fuel(BDF) which is easily produced from vegetable oils such as soybean oil and rice bran oil can be effectively used as an alternative fuel in diesel engine. But biodiesel fuel can affect the performance and emissions in diesel engine because it has different chemical and physical properties from diesel fuel. To investigate the combustion characteristics of biodiesel fuel as an alternative fuel for D.I. diesel engine, the experiments were carried out at the three-cylinder, four stroke D.I. diesel engine with T/C. Experimental parameters adopted a conventional diesel fuel and a blend of biodiesel fuel derived from soybean. As a result of experiments in a test engine, BSFC with blend of BDF resulted in higher than with diesel fuel. The ignition delay decreased with blend of BDF than with diesel fuel.

• Journal of Power System Engineering
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• v.13 no.6
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• pp.51-56
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• 2009

Recently, lots of researchers have been attracted to develop various alternative fuels in diesel engine. The use of biodiesel fuel(BDF) is an effective way of substituting diesel fuel in the long run. But biodiesel fuel can affect the performance and emissions in diesel engine because it has different chemical and physical properties from diesel fuel. In this study, to investigate the combustion characteristics of biodiesel fuel as an alternative fuel for D.I. diesel engine, experiments were carried out at the three-cylinder, four stroke D.I. diesel engine with T/C. As a result, shorter ignition delays were observed for the biodiesel blend cases relative to the diesel oil. The pick value of premixed combustion for the rate of heat release is increased with decreasing C.F.W. temperature.

• Journal of the korean Society of Automotive Engineers
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• v.15 no.3
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• pp.19-31
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• 1993

디젤자동차는 가솔린 자동차에 비하여 연료소비효율(fuel economy)이 20-30% 정도 높고 고출력을 낼수 있어 이의 수요가 증가하고 있다. 본 고에서는 디젤자동차에서 배출되는 수많은 화학물질중에서 문제가 되고 있는 입자상물질, NOx 및 SO$_{2}$를 제거하는 기술에 대하여 살펴본다. 이러한 오염물질의 저감을 위하여는 배기가스 재순환, 분사시기의 조절, 인터쿨링 같은 연소기술의 개선과 유황분이 적고, 방향족화합물의 함량이 적은 청정연료를 사용하여 어느 수준까지는 목적을 달성할 수 있다. 1. 디젤자동차 배출허용기준. 2. 배기가스 정화기술. 2.1 트랩기술(trap technology). 2.2 재생기술(regeneration technology). 2.3 제어 및 센서기술(control and sensor technology)

• Journal of Power System Engineering
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• v.9 no.3
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• pp.21-25
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• 2005

디젤분무가 연소실 벽에 충돌할 때의 연료부착특성을 파악하기 위하여 평판에 충돌하는 디젤 분무의 부착특성을 실험적으로 연구하였다. 투명 아크릴판을 이용하여 연료액막과 충돌분무를 동시에 촬영하였고, 충돌분무의 성장에 따른 연료액막의 성장도 함께 측정되었다. 부착된 연료는 연료액막 및 부착액적들로 나누어서 측정할 수 있었으며 그 결과 연료액막 주변에 무수한 연료액적이 부착함을 알 수 있었다. 시간에 따른 부착연료비를 예측하기 위하여 몇 가지 가정이 사용되었다. 그 결과 시간경과에 따른 부착연료비를 충돌거리 10mm, 30mm, 50mm에 대하여 예측할 수 있었다.